[RFC PATCH v1 07/21] cli: Add Busybox upstream hush.c file.

This commit adds new file cli_hush_2021_upstream.c, it is a copy of Busybox hush file it was of time to Busybox commit 37460f5da.

Signed-off-by: Francis Laniel francis.laniel@amarulasolutions.com --- common/cli_hush_2021_upstream.c | 12162 ++++++++++++++++++++++++++++++ 1 file changed, 12162 insertions(+) create mode 100644 common/cli_hush_2021_upstream.c

diff --git a/common/cli_hush_2021_upstream.c b/common/cli_hush_2021_upstream.c new file mode 100644 index 0000000000..c970d9097e --- /dev/null +++ b/common/cli_hush_2021_upstream.c @@ -0,0 +1,12162 @@ +/* vi: set sw=4 ts=4: */ +/* + * A prototype Bourne shell grammar parser. + * Intended to follow the original Thompson and Ritchie + * "small and simple is beautiful" philosophy, which + * incidentally is a good match to today's BusyBox. + * + * Copyright (C) 2000,2001 Larry Doolittle larry@doolittle.boa.org + * Copyright (C) 2008,2009 Denys Vlasenko vda.linux@googlemail.com + * + * Licensed under GPLv2 or later, see file LICENSE in this source tree. + * + * Credits: + * The parser routines proper are all original material, first + * written Dec 2000 and Jan 2001 by Larry Doolittle. The + * execution engine, the builtins, and much of the underlying + * support has been adapted from busybox-0.49pre's lash, which is + * Copyright (C) 1999-2004 by Erik Andersen andersen@codepoet.org + * written by Erik Andersen andersen@codepoet.org. That, in turn, + * is based in part on ladsh.c, by Michael K. Johnson and Erik W. + * Troan, which they placed in the public domain. I don't know + * how much of the Johnson/Troan code has survived the repeated + * rewrites. + * + * Other credits: + * o_addchr derived from similar w_addchar function in glibc-2.2. + * parse_redirect, redirect_opt_num, and big chunks of main + * and many builtins derived from contributions by Erik Andersen. + * Miscellaneous bugfixes from Matt Kraai. + * + * There are two big (and related) architecture differences between + * this parser and the lash parser. One is that this version is + * actually designed from the ground up to understand nearly all + * of the Bourne grammar. The second, consequential change is that + * the parser and input reader have been turned inside out. Now, + * the parser is in control, and asks for input as needed. The old + * way had the input reader in control, and it asked for parsing to + * take place as needed. The new way makes it much easier to properly + * handle the recursion implicit in the various substitutions, especially + * across continuation lines. + * + * TODOs: + * grep for "TODO" and fix (some of them are easy) + * make complex ${var%...} constructs support optional + * make here documents optional + * special variables (done: PWD, PPID, RANDOM) + * follow IFS rules more precisely, including update semantics + * tilde expansion + * aliases + * "command" missing features: + * command -p CMD: run CMD using default $PATH + * (can use this to override standalone shell as well?) + * command BLTIN: disables special-ness (e.g. errors do not abort) + * command -V CMD1 CMD2 CMD3 (multiple args) (not in standard) + * builtins mandated by standards we don't support: + * [un]alias, fc: + * fc -l[nr] [BEG] [END]: list range of commands in history + * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands + * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP + * + * Bash compat TODO: + * redirection of stdout+stderr: &> and >& + * reserved words: function select + * advanced test: [[ ]] + * process substitution: <(list) and >(list) + * let EXPR [EXPR...] + * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION) + * If the last arg evaluates to 0, let returns 1; 0 otherwise. + * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used) + * ((EXPR)) + * The EXPR is evaluated according to ARITHMETIC EVALUATION. + * This is exactly equivalent to let "EXPR". + * $[EXPR]: synonym for $((EXPR)) + * indirect expansion: ${!VAR} + * substring op on @: ${@:n:m} + * + * Won't do: + * Some builtins mandated by standards: + * newgrp [GRP]: not a builtin in bash but a suid binary + * which spawns a new shell with new group ID + * + * Status of [[ support: + * [[ args ]] are CMD_SINGLEWORD_NOGLOB: + * v='a b'; [[ $v = 'a b' ]]; echo 0:$? + * [[ /bin/n* ]]; echo 0:$? + * = is glob match operator, not equality operator: STR = GLOB + * == same as = + * =~ is regex match operator: STR =~ REGEX + * TODO: + * quoting needs to be considered (-f is an operator, "-f" and ""-f are not; etc) + * in word = GLOB, quoting should be significant on char-by-char basis: a*cd"*" + */ +//config:config HUSH +//config: bool "hush (68 kb)" +//config: default y +//config: select SHELL_HUSH +//config: help +//config: hush is a small shell. It handles the normal flow control +//config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops, +//config: case/esac. Redirections, here documents, $((arithmetic)) +//config: and functions are supported. +//config: +//config: It will compile and work on no-mmu systems. +//config: +//config: It does not handle select, aliases, tilde expansion, +//config: &>file and >&file redirection of stdout+stderr. +//config: +// This option is visible (has a description) to make it possible to select +// a "scripted" applet (such as NOLOGIN) but avoid selecting any shells: +//config:config SHELL_HUSH +//config: bool "Internal shell for embedded script support" +//config: default n +//config: +//config:# hush options +//config:# It's only needed to get "nice" menuconfig indenting. +//config:if SHELL_HUSH || HUSH || SH_IS_HUSH || BASH_IS_HUSH +//config: +//config:config HUSH_BASH_COMPAT +//config: bool "bash-compatible extensions" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_BRACE_EXPANSION +//config: bool "Brace expansion" +//config: default y +//config: depends on HUSH_BASH_COMPAT +//config: help +//config: Enable {abc,def} extension. +//config: +//config:config HUSH_BASH_SOURCE_CURDIR +//config: bool "'source' and '.' builtins search current directory after $PATH" +//config: default n # do not encourage non-standard behavior +//config: depends on HUSH_BASH_COMPAT +//config: help +//config: This is not compliant with standards. Avoid if possible. +//config: +//config:config HUSH_LINENO_VAR +//config: bool "$LINENO variable (bashism)" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_INTERACTIVE +//config: bool "Interactive mode" +//config: default y +//config: depends on SHELL_HUSH +//config: help +//config: Enable interactive mode (prompt and command editing). +//config: Without this, hush simply reads and executes commands +//config: from stdin just like a shell script from a file. +//config: No prompt, no PS1/PS2 magic shell variables. +//config: +//config:config HUSH_SAVEHISTORY +//config: bool "Save command history to .hush_history" +//config: default y +//config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY +//config: +//config:config HUSH_JOB +//config: bool "Job control" +//config: default y +//config: depends on HUSH_INTERACTIVE +//config: help +//config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current +//config: command (not entire shell), fg/bg builtins work. Without this option, +//config: "cmd &" still works by simply spawning a process and immediately +//config: prompting for next command (or executing next command in a script), +//config: but no separate process group is formed. +//config: +//config:config HUSH_TICK +//config: bool "Support command substitution" +//config: default y +//config: depends on SHELL_HUSH +//config: help +//config: Enable `command` and $(command). +//config: +//config:config HUSH_IF +//config: bool "Support if/then/elif/else/fi" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_LOOPS +//config: bool "Support for, while and until loops" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_CASE +//config: bool "Support case ... esac statement" +//config: default y +//config: depends on SHELL_HUSH +//config: help +//config: Enable case ... esac statement. +400 bytes. +//config: +//config:config HUSH_FUNCTIONS +//config: bool "Support funcname() { commands; } syntax" +//config: default y +//config: depends on SHELL_HUSH +//config: help +//config: Enable support for shell functions. +800 bytes. +//config: +//config:config HUSH_LOCAL +//config: bool "local builtin" +//config: default y +//config: depends on HUSH_FUNCTIONS +//config: help +//config: Enable support for local variables in functions. +//config: +//config:config HUSH_RANDOM_SUPPORT +//config: bool "Pseudorandom generator and $RANDOM variable" +//config: default y +//config: depends on SHELL_HUSH +//config: help +//config: Enable pseudorandom generator and dynamic variable "$RANDOM". +//config: Each read of "$RANDOM" will generate a new pseudorandom value. +//config: +//config:config HUSH_MODE_X +//config: bool "Support 'hush -x' option and 'set -x' command" +//config: default y +//config: depends on SHELL_HUSH +//config: help +//config: This instructs hush to print commands before execution. +//config: Adds ~300 bytes. +//config: +//config:config HUSH_ECHO +//config: bool "echo builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_PRINTF +//config: bool "printf builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_TEST +//config: bool "test builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_HELP +//config: bool "help builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_EXPORT +//config: bool "export builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_EXPORT_N +//config: bool "Support 'export -n' option" +//config: default y +//config: depends on HUSH_EXPORT +//config: help +//config: export -n unexports variables. It is a bash extension. +//config: +//config:config HUSH_READONLY +//config: bool "readonly builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: help +//config: Enable support for read-only variables. +//config: +//config:config HUSH_KILL +//config: bool "kill builtin (supports kill %jobspec)" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_WAIT +//config: bool "wait builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_COMMAND +//config: bool "command builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_TRAP +//config: bool "trap builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_TYPE +//config: bool "type builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_TIMES +//config: bool "times builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_READ +//config: bool "read builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_SET +//config: bool "set builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_UNSET +//config: bool "unset builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_ULIMIT +//config: bool "ulimit builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_UMASK +//config: bool "umask builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_GETOPTS +//config: bool "getopts builtin" +//config: default y +//config: depends on SHELL_HUSH +//config: +//config:config HUSH_MEMLEAK +//config: bool "memleak builtin (debugging)" +//config: default n +//config: depends on SHELL_HUSH +//config: +//config:endif # hush options + +//applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP)) +// APPLET_ODDNAME:name main location suid_type help +//applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush)) +//applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush)) + +//kbuild:lib-$(CONFIG_SHELL_HUSH) += hush.o match.o shell_common.o +//kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o + +/* -i (interactive) is also accepted, + * but does nothing, therefore not shown in help. + * NOMMU-specific options are not meant to be used by users, + * therefore we don't show them either. + */ +//usage:#define hush_trivial_usage +//usage: "[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE [ARGS] | -s [ARGS]]" +//usage:#define hush_full_usage "\n\n" +//usage: "Unix shell interpreter" + +#if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \ + || defined(__APPLE__) \ + ) +# include <malloc.h> /* for malloc_trim */ +#endif +#include <glob.h> +/* #include <dmalloc.h> */ +#if ENABLE_HUSH_CASE +# include <fnmatch.h> +#endif +#include <sys/times.h> +#include <sys/utsname.h> /* for setting $HOSTNAME */ + +#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */ +#include "unicode.h" +#include "shell_common.h" +#include "math.h" +#include "match.h" +#if ENABLE_HUSH_RANDOM_SUPPORT +# include "random.h" +#else +# define CLEAR_RANDOM_T(rnd) ((void)0) +#endif +#ifndef O_CLOEXEC +# define O_CLOEXEC 0 +#endif +#ifndef F_DUPFD_CLOEXEC +# define F_DUPFD_CLOEXEC F_DUPFD +#endif + +#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS && !(ENABLE_ASH || ENABLE_SH_IS_ASH || ENABLE_BASH_IS_ASH) +# include "embedded_scripts.h" +#else +# define NUM_SCRIPTS 0 +#endif + +/* So far, all bash compat is controlled by one config option */ +/* Separate defines document which part of code implements what */ +#define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT +#define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT +#define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT +#define BASH_DOLLAR_SQUOTE ENABLE_HUSH_BASH_COMPAT +#define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT +#define BASH_EPOCH_VARS ENABLE_HUSH_BASH_COMPAT +#define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST) +#define BASH_READ_D ENABLE_HUSH_BASH_COMPAT + + +/* Build knobs */ +#define LEAK_HUNTING 0 +#define BUILD_AS_NOMMU 0 +/* Enable/disable sanity checks. Ok to enable in production, + * only adds a bit of bloat. Set to >1 to get non-production level verbosity. + * Keeping 1 for now even in released versions. + */ +#define HUSH_DEBUG 1 +/* Slightly bigger (+200 bytes), but faster hush. + * So far it only enables a trick with counting SIGCHLDs and forks, + * which allows us to do fewer waitpid's. + * (we can detect a case where neither forks were done nor SIGCHLDs happened + * and therefore waitpid will return the same result as last time) + */ +#define ENABLE_HUSH_FAST 0 +/* TODO: implement simplified code for users which do not need ${var%...} ops + * So far ${var%...} ops are always enabled: + */ +#define ENABLE_HUSH_DOLLAR_OPS 1 + + +#if BUILD_AS_NOMMU +# undef BB_MMU +# undef USE_FOR_NOMMU +# undef USE_FOR_MMU +# define BB_MMU 0 +# define USE_FOR_NOMMU(...) __VA_ARGS__ +# define USE_FOR_MMU(...) +#endif + +#include "NUM_APPLETS.h" +#if NUM_APPLETS == 1 +/* STANDALONE does not make sense, and won't compile */ +# undef CONFIG_FEATURE_SH_STANDALONE +# undef ENABLE_FEATURE_SH_STANDALONE +# undef IF_FEATURE_SH_STANDALONE +# undef IF_NOT_FEATURE_SH_STANDALONE +# define ENABLE_FEATURE_SH_STANDALONE 0 +# define IF_FEATURE_SH_STANDALONE(...) +# define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__ +#endif + +#if !ENABLE_HUSH_INTERACTIVE +# undef ENABLE_FEATURE_EDITING +# define ENABLE_FEATURE_EDITING 0 +# undef ENABLE_FEATURE_EDITING_FANCY_PROMPT +# define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0 +# undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT +# define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0 +#endif + +/* Do we support ANY keywords? */ +#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE +# define HAS_KEYWORDS 1 +# define IF_HAS_KEYWORDS(...) __VA_ARGS__ +# define IF_HAS_NO_KEYWORDS(...) +#else +# define HAS_KEYWORDS 0 +# define IF_HAS_KEYWORDS(...) +# define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__ +#endif + +/* If you comment out one of these below, it will be #defined later + * to perform debug printfs to stderr: */ +#define debug_printf(...) do {} while (0) +/* Finer-grained debug switches */ +#define debug_printf_parse(...) do {} while (0) +#define debug_printf_heredoc(...) do {} while (0) +#define debug_print_tree(a, b) do {} while (0) +#define debug_printf_exec(...) do {} while (0) +#define debug_printf_env(...) do {} while (0) +#define debug_printf_jobs(...) do {} while (0) +#define debug_printf_expand(...) do {} while (0) +#define debug_printf_varexp(...) do {} while (0) +#define debug_printf_glob(...) do {} while (0) +#define debug_printf_redir(...) do {} while (0) +#define debug_printf_list(...) do {} while (0) +#define debug_printf_subst(...) do {} while (0) +#define debug_printf_prompt(...) do {} while (0) +#define debug_printf_clean(...) do {} while (0) + +#define ERR_PTR ((void*)(long)1) + +#define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n" + +#define _SPECIAL_VARS_STR "_*@$!?#-" +#define SPECIAL_VARS_STR ("_*@$!?#-" + 1) +#define NUMERIC_SPECVARS_STR ("_*@$!?#-" + 3) +#if BASH_PATTERN_SUBST +/* Support / and // replace ops */ +/* Note that // is stored as \ in "encoded" string representation */ +# define VAR_ENCODED_SUBST_OPS "\/%#:-=+?" +# define VAR_SUBST_OPS ("\/%#:-=+?" + 1) +# define MINUS_PLUS_EQUAL_QUESTION ("\/%#:-=+?" + 5) +#else +# define VAR_ENCODED_SUBST_OPS "%#:-=+?" +# define VAR_SUBST_OPS "%#:-=+?" +# define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3) +#endif + +#define SPECIAL_VAR_SYMBOL_STR "\3" +#define SPECIAL_VAR_SYMBOL 3 +/* The "variable" with name "\1" emits string "\3". Testcase: "echo ^C" */ +#define SPECIAL_VAR_QUOTED_SVS 1 + +struct variable; + +static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER; + +/* This supports saving pointers malloced in vfork child, + * to be freed in the parent. + */ +#if !BB_MMU +typedef struct nommu_save_t { + struct variable *old_vars; + char **argv; + char **argv_from_re_execing; +} nommu_save_t; +#endif + +enum { + RES_NONE = 0, +#if ENABLE_HUSH_IF + RES_IF , + RES_THEN , + RES_ELIF , + RES_ELSE , + RES_FI , +#endif +#if ENABLE_HUSH_LOOPS + RES_FOR , + RES_WHILE , + RES_UNTIL , + RES_DO , + RES_DONE , +#endif +#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE + RES_IN , +#endif +#if ENABLE_HUSH_CASE + RES_CASE , + /* three pseudo-keywords support contrived "case" syntax: */ + RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */ + RES_MATCH , /* "word)" */ + RES_CASE_BODY, /* "this command is inside CASE" */ + RES_ESAC , +#endif + RES_XXXX , + RES_SNTX +}; + +typedef struct o_string { + char *data; + int length; /* position where data is appended */ + int maxlen; + int o_expflags; + /* At least some part of the string was inside '' or "", + * possibly empty one: word"", wo''rd etc. */ + smallint has_quoted_part; + smallint has_empty_slot; + smallint ended_in_ifs; +} o_string; +enum { + EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */ + EXP_FLAG_GLOB = 0x2, + /* Protect newly added chars against globbing + * by prepending \ to *, ?, [, \ */ + EXP_FLAG_ESC_GLOB_CHARS = 0x1, +}; +/* Used for initialization: o_string foo = NULL_O_STRING; */ +#define NULL_O_STRING { NULL } + +#ifndef debug_printf_parse +static const char *const assignment_flag[] = { + "MAYBE_ASSIGNMENT", + "DEFINITELY_ASSIGNMENT", + "NOT_ASSIGNMENT", + "WORD_IS_KEYWORD", +}; +#endif + +/* We almost can use standard FILE api, but we need an ability to move + * its fd when redirects coincide with it. No api exists for that + * (RFE for it at https://sourceware.org/bugzilla/show_bug.cgi?id=21902). + * HFILE is our internal alternative. Only supports reading. + * Since we now can, we incorporate linked list of all opened HFILEs + * into the struct (used to be a separate mini-list). + */ +typedef struct HFILE { + char *cur; + char *end; + struct HFILE *next_hfile; + int fd; + char buf[1024]; +} HFILE; + +typedef struct in_str { + const char *p; + int peek_buf[2]; + int last_char; + HFILE *file; +} in_str; + +/* The descrip member of this structure is only used to make + * debugging output pretty */ +static const struct { + int32_t mode; + signed char default_fd; + char descrip[3]; +} redir_table[] ALIGN4 = { + { O_RDONLY, 0, "<" }, + { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" }, + { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" }, + { O_CREAT|O_RDWR, 1, "<>" }, + { O_RDONLY, 0, "<<" }, +/* Should not be needed. Bogus default_fd helps in debugging */ +/* { O_RDONLY, 77, "<<" }, */ +}; + +struct redir_struct { + struct redir_struct *next; + char *rd_filename; /* filename */ + int rd_fd; /* fd to redirect */ + /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */ + int rd_dup; + smallint rd_type; /* (enum redir_type) */ + /* note: for heredocs, rd_filename contains heredoc delimiter, + * and subsequently heredoc itself; and rd_dup is a bitmask: + * bit 0: do we need to trim leading tabs? + * bit 1: is heredoc quoted (<<'delim' syntax) ? + */ +}; +typedef enum redir_type { + REDIRECT_INPUT = 0, + REDIRECT_OVERWRITE = 1, + REDIRECT_APPEND = 2, + REDIRECT_IO = 3, + REDIRECT_HEREDOC = 4, + REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */ + + REDIRFD_CLOSE = -3, + REDIRFD_SYNTAX_ERR = -2, + REDIRFD_TO_FILE = -1, + /* otherwise, rd_fd is redirected to rd_dup */ + + HEREDOC_SKIPTABS = 1, + HEREDOC_QUOTED = 2, +} redir_type; + + +struct command { + pid_t pid; /* 0 if exited */ + unsigned assignment_cnt; /* how many argv[i] are assignments? */ +#if ENABLE_HUSH_LINENO_VAR + unsigned lineno; +#endif + smallint cmd_type; /* CMD_xxx */ +#define CMD_NORMAL 0 +#define CMD_SUBSHELL 1 +#if BASH_TEST2 +/* used for "[[ EXPR ]]" */ +# define CMD_TEST2_SINGLEWORD_NOGLOB 2 +#endif +#if BASH_TEST2 || ENABLE_HUSH_LOCAL || ENABLE_HUSH_EXPORT || ENABLE_HUSH_READONLY +/* used to prevent word splitting and globbing in "export v=t*" */ +# define CMD_SINGLEWORD_NOGLOB 3 +#endif +#if ENABLE_HUSH_FUNCTIONS +# define CMD_FUNCDEF 4 +#endif + + smalluint cmd_exitcode; + /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */ + struct pipe *group; +#if !BB_MMU + char *group_as_string; +#endif +#if ENABLE_HUSH_FUNCTIONS + struct function *child_func; +/* This field is used to prevent a bug here: + * while...do f1() {a;}; f1; f1() {b;}; f1; done + * When we execute "f1() {a;}" cmd, we create new function and clear + * cmd->group, cmd->group_as_string, cmd->argv[0]. + * When we execute "f1() {b;}", we notice that f1 exists, + * and that its "parent cmd" struct is still "alive", + * we put those fields back into cmd->xxx + * (struct function has ->parent_cmd ptr to facilitate that). + * When we loop back, we can execute "f1() {a;}" again and set f1 correctly. + * Without this trick, loop would execute a;b;b;b;... + * instead of correct sequence a;b;a;b;... + * When command is freed, it severs the link + * (sets ->child_func->parent_cmd to NULL). + */ +#endif + char **argv; /* command name and arguments */ +/* argv vector may contain variable references (^Cvar^C, ^C0^C etc) + * and on execution these are substituted with their values. + * Substitution can make _several_ words out of one argv[n]! + * Example: argv[0]=='.^C*^C.' here: echo .$*. + * References of the form ^C`cmd arg^C are `cmd arg` substitutions. + */ + struct redir_struct *redirects; /* I/O redirections */ +}; +/* Is there anything in this command at all? */ +#define IS_NULL_CMD(cmd) \ + (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects) + +struct pipe { + struct pipe *next; + int num_cmds; /* total number of commands in pipe */ + int alive_cmds; /* number of commands running (not exited) */ + int stopped_cmds; /* number of commands alive, but stopped */ +#if ENABLE_HUSH_JOB + unsigned jobid; /* job number */ + pid_t pgrp; /* process group ID for the job */ + char *cmdtext; /* name of job */ +#endif + struct command *cmds; /* array of commands in pipe */ + smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */ + IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */ + IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */ +}; +typedef enum pipe_style { + PIPE_SEQ = 0, + PIPE_AND = 1, + PIPE_OR = 2, + PIPE_BG = 3, +} pipe_style; +/* Is there anything in this pipe at all? */ +#define IS_NULL_PIPE(pi) \ + ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE)) + +/* This holds pointers to the various results of parsing */ +struct parse_context { + /* linked list of pipes */ + struct pipe *list_head; + /* last pipe (being constructed right now) */ + struct pipe *pipe; + /* last command in pipe (being constructed right now) */ + struct command *command; + /* last redirect in command->redirects list */ + struct redir_struct *pending_redirect; + o_string word; +#if !BB_MMU + o_string as_string; +#endif + smallint is_assignment; /* 0:maybe, 1:yes, 2:no, 3:keyword */ +#if HAS_KEYWORDS + smallint ctx_res_w; + smallint ctx_inverted; /* "! cmd | cmd" */ +#if ENABLE_HUSH_CASE + smallint ctx_dsemicolon; /* ";;" seen */ +#endif + /* bitmask of FLAG_xxx, for figuring out valid reserved words */ + int old_flag; + /* group we are enclosed in: + * example: "if pipe1; pipe2; then pipe3; fi" + * when we see "if" or "then", we malloc and copy current context, + * and make ->stack point to it. then we parse pipeN. + * when closing "then" / fi" / whatever is found, + * we move list_head into ->stack->command->group, + * copy ->stack into current context, and delete ->stack. + * (parsing of { list } and ( list ) doesn't use this method) + */ + struct parse_context *stack; +#endif +}; +enum { + MAYBE_ASSIGNMENT = 0, + DEFINITELY_ASSIGNMENT = 1, + NOT_ASSIGNMENT = 2, + /* Not an assignment, but next word may be: "if v=xyz cmd;" */ + WORD_IS_KEYWORD = 3, +}; + +/* On program start, environ points to initial environment. + * putenv adds new pointers into it, unsetenv removes them. + * Neither of these (de)allocates the strings. + * setenv allocates new strings in malloc space and does putenv, + * and thus setenv is unusable (leaky) for shell's purposes */ +#define setenv(...) setenv_is_leaky_dont_use() +struct variable { + struct variable *next; + char *varstr; /* points to "name=" portion */ + int max_len; /* if > 0, name is part of initial env; else name is malloced */ + uint16_t var_nest_level; + smallint flg_export; /* putenv should be done on this var */ + smallint flg_read_only; +}; + +enum { + BC_BREAK = 1, + BC_CONTINUE = 2, +}; + +#if ENABLE_HUSH_FUNCTIONS +struct function { + struct function *next; + char *name; + struct command *parent_cmd; + struct pipe *body; +# if !BB_MMU + char *body_as_string; +# endif +}; +#endif + + +/* set -/+o OPT support. (TODO: make it optional) + * bash supports the following opts: + * allexport off + * braceexpand on + * emacs on + * errexit off + * errtrace off + * functrace off + * hashall on + * histexpand off + * history on + * ignoreeof off + * interactive-comments on + * keyword off + * monitor on + * noclobber off + * noexec off + * noglob off + * nolog off + * notify off + * nounset off + * onecmd off + * physical off + * pipefail off + * posix off + * privileged off + * verbose off + * vi off + * xtrace off + */ +static const char o_opt_strings[] ALIGN1 = + "pipefail\0" + "noexec\0" + "errexit\0" +#if ENABLE_HUSH_MODE_X + "xtrace\0" +#endif + ; +enum { + OPT_O_PIPEFAIL, + OPT_O_NOEXEC, + OPT_O_ERREXIT, +#if ENABLE_HUSH_MODE_X + OPT_O_XTRACE, +#endif + NUM_OPT_O +}; + +/* "Globals" within this file */ +/* Sorted roughly by size (smaller offsets == smaller code) */ +struct globals { + /* interactive_fd != 0 means we are an interactive shell. + * If we are, then saved_tty_pgrp can also be != 0, meaning + * that controlling tty is available. With saved_tty_pgrp == 0, + * job control still works, but terminal signals + * (^C, ^Z, ^Y, ^) won't work at all, and background + * process groups can only be created with "cmd &". + * With saved_tty_pgrp != 0, hush will use tcsetpgrp() + * to give tty to the foreground process group, + * and will take it back when the group is stopped (^Z) + * or killed (^C). + */ +#if ENABLE_HUSH_INTERACTIVE + /* 'interactive_fd' is a fd# open to ctty, if we have one + * _AND_ if we decided to act interactively */ + int interactive_fd; + IF_NOT_FEATURE_EDITING_FANCY_PROMPT(char *PS1;) +# define G_interactive_fd (G.interactive_fd) +#else +# define G_interactive_fd 0 +#endif +#if ENABLE_FEATURE_EDITING + line_input_t *line_input_state; +#endif + pid_t root_pid; + pid_t root_ppid; + pid_t last_bg_pid; +#if ENABLE_HUSH_RANDOM_SUPPORT + random_t random_gen; +#endif +#if ENABLE_HUSH_JOB + int run_list_level; + unsigned last_jobid; + pid_t saved_tty_pgrp; + struct pipe *job_list; +# define G_saved_tty_pgrp (G.saved_tty_pgrp) +#else +# define G_saved_tty_pgrp 0 +#endif + /* How deeply are we in context where "set -e" is ignored */ + int errexit_depth; + /* "set -e" rules (do we follow them correctly?): + * Exit if pipe, list, or compound command exits with a non-zero status. + * Shell does not exit if failed command is part of condition in + * if/while, part of && or || list except the last command, any command + * in a pipe but the last, or if the command's return value is being + * inverted with !. If a compound command other than a subshell returns a + * non-zero status because a command failed while -e was being ignored, the + * shell does not exit. A trap on ERR, if set, is executed before the shell + * exits [ERR is a bashism]. + * + * If a compound command or function executes in a context where -e is + * ignored, none of the commands executed within are affected by the -e + * setting. If a compound command or function sets -e while executing in a + * context where -e is ignored, that setting does not have any effect until + * the compound command or the command containing the function call completes. + */ + + char o_opt[NUM_OPT_O]; +#if ENABLE_HUSH_MODE_X +# define G_x_mode (G.o_opt[OPT_O_XTRACE]) +#else +# define G_x_mode 0 +#endif + char opt_s; + char opt_c; +#if ENABLE_HUSH_INTERACTIVE + smallint promptmode; /* 0: PS1, 1: PS2 */ +#endif + smallint flag_SIGINT; +#if ENABLE_HUSH_LOOPS + smallint flag_break_continue; +#endif +#if ENABLE_HUSH_FUNCTIONS + /* 0: outside of a function (or sourced file) + * -1: inside of a function, ok to use return builtin + * 1: return is invoked, skip all till end of func + */ + smallint flag_return_in_progress; +# define G_flag_return_in_progress (G.flag_return_in_progress) +#else +# define G_flag_return_in_progress 0 +#endif + smallint exiting; /* used to prevent EXIT trap recursion */ + /* These support $? */ + smalluint last_exitcode; + smalluint expand_exitcode; + smalluint last_bg_pid_exitcode; +#if ENABLE_HUSH_SET + /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */ + smalluint global_args_malloced; +# define G_global_args_malloced (G.global_args_malloced) +#else +# define G_global_args_malloced 0 +#endif +#if ENABLE_HUSH_BASH_COMPAT + int dead_job_exitcode; /* for "wait -n" */ +#endif + /* how many non-NULL argv's we have. NB: $# + 1 */ + int global_argc; + char **global_argv; +#if !BB_MMU + char *argv0_for_re_execing; +#endif +#if ENABLE_HUSH_LOOPS + unsigned depth_break_continue; + unsigned depth_of_loop; +#endif +#if ENABLE_HUSH_GETOPTS + unsigned getopt_count; +#endif + const char *ifs; + char *ifs_whitespace; /* = G.ifs or malloced */ + const char *cwd; + struct variable *top_var; + char **expanded_assignments; + struct variable **shadowed_vars_pp; + unsigned var_nest_level; +#if ENABLE_HUSH_FUNCTIONS +# if ENABLE_HUSH_LOCAL + unsigned func_nest_level; /* solely to prevent "local v" in non-functions */ +# endif + struct function *top_func; +#endif + /* Signal and trap handling */ +#if ENABLE_HUSH_FAST + unsigned count_SIGCHLD; + unsigned handled_SIGCHLD; + smallint we_have_children; +#endif +#if ENABLE_HUSH_LINENO_VAR + unsigned parse_lineno; + unsigned execute_lineno; +#endif + HFILE *HFILE_list; + HFILE *HFILE_stdin; + /* Which signals have non-DFL handler (even with no traps set)? + * Set at the start to: + * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS) + * SPECIAL_INTERACTIVE_SIGS are cleared after fork. + * The rest is cleared right before execv syscalls. + * Other than these two times, never modified. + */ + unsigned special_sig_mask; +#if ENABLE_HUSH_JOB + unsigned fatal_sig_mask; +# define G_fatal_sig_mask (G.fatal_sig_mask) +#else +# define G_fatal_sig_mask 0 +#endif +#if ENABLE_HUSH_TRAP + int pre_trap_exitcode; +# if ENABLE_HUSH_FUNCTIONS + int return_exitcode; +# endif + char **traps; /* char *traps[NSIG] */ +# define G_traps G.traps +#else +# define G_traps ((char**)NULL) +#endif + sigset_t pending_set; +#if ENABLE_HUSH_MEMLEAK + unsigned long memleak_value; +#endif +#if ENABLE_HUSH_MODE_X + unsigned x_mode_depth; + /* "set -x" output should not be redirectable with subsequent 2>FILE. + * We dup fd#2 to x_mode_fd when "set -x" is executed, and use it + * for all subsequent output. + */ + int x_mode_fd; + o_string x_mode_buf; +#endif +#if HUSH_DEBUG >= 2 + int debug_indent; +#endif + struct sigaction sa; + char optstring_buf[sizeof("eixcs")]; +#if BASH_EPOCH_VARS + char epoch_buf[sizeof("%llu.nnnnnn") + sizeof(long long)*3]; +#endif +#if ENABLE_FEATURE_EDITING + char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN]; +#endif +}; +#define G (*ptr_to_globals) +/* Not #defining name to G.name - this quickly gets unwieldy + * (too many defines). Also, I actually prefer to see when a variable + * is global, thus "G." prefix is a useful hint */ +#define INIT_G() do { \ + SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \ + /* memset(&G.sa, 0, sizeof(G.sa)); */ \ + sigfillset(&G.sa.sa_mask); \ + G.sa.sa_flags = SA_RESTART; \ +} while (0) + + +/* Function prototypes for builtins */ +static int builtin_cd(char **argv) FAST_FUNC; +#if ENABLE_HUSH_ECHO +static int builtin_echo(char **argv) FAST_FUNC; +#endif +static int builtin_eval(char **argv) FAST_FUNC; +static int builtin_exec(char **argv) FAST_FUNC; +static int builtin_exit(char **argv) FAST_FUNC; +#if ENABLE_HUSH_EXPORT +static int builtin_export(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_READONLY +static int builtin_readonly(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_JOB +static int builtin_fg_bg(char **argv) FAST_FUNC; +static int builtin_jobs(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_GETOPTS +static int builtin_getopts(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_HELP +static int builtin_help(char **argv) FAST_FUNC; +#endif +#if MAX_HISTORY && ENABLE_FEATURE_EDITING +static int builtin_history(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_LOCAL +static int builtin_local(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_MEMLEAK +static int builtin_memleak(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_PRINTF +static int builtin_printf(char **argv) FAST_FUNC; +#endif +static int builtin_pwd(char **argv) FAST_FUNC; +#if ENABLE_HUSH_READ +static int builtin_read(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_SET +static int builtin_set(char **argv) FAST_FUNC; +#endif +static int builtin_shift(char **argv) FAST_FUNC; +static int builtin_source(char **argv) FAST_FUNC; +#if ENABLE_HUSH_TEST || BASH_TEST2 +static int builtin_test(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_TRAP +static int builtin_trap(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_TYPE +static int builtin_type(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_TIMES +static int builtin_times(char **argv) FAST_FUNC; +#endif +static int builtin_true(char **argv) FAST_FUNC; +#if ENABLE_HUSH_UMASK +static int builtin_umask(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_UNSET +static int builtin_unset(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_KILL +static int builtin_kill(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_WAIT +static int builtin_wait(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_LOOPS +static int builtin_break(char **argv) FAST_FUNC; +static int builtin_continue(char **argv) FAST_FUNC; +#endif +#if ENABLE_HUSH_FUNCTIONS +static int builtin_return(char **argv) FAST_FUNC; +#endif + +/* Table of built-in functions. They can be forked or not, depending on + * context: within pipes, they fork. As simple commands, they do not. + * When used in non-forking context, they can change global variables + * in the parent shell process. If forked, of course they cannot. + * For example, 'unset foo | whatever' will parse and run, but foo will + * still be set at the end. */ +struct built_in_command { + const char *b_cmd; + int (*b_function)(char **argv) FAST_FUNC; +#if ENABLE_HUSH_HELP + const char *b_descr; +# define BLTIN(cmd, func, help) { cmd, func, help } +#else +# define BLTIN(cmd, func, help) { cmd, func } +#endif +}; + +static const struct built_in_command bltins1[] ALIGN_PTR = { + BLTIN("." , builtin_source , "Run commands in file"), + BLTIN(":" , builtin_true , NULL), +#if ENABLE_HUSH_JOB + BLTIN("bg" , builtin_fg_bg , "Resume job in background"), +#endif +#if ENABLE_HUSH_LOOPS + BLTIN("break" , builtin_break , "Exit loop"), +#endif + BLTIN("cd" , builtin_cd , "Change directory"), +#if ENABLE_HUSH_LOOPS + BLTIN("continue" , builtin_continue, "Start new loop iteration"), +#endif + BLTIN("eval" , builtin_eval , "Construct and run shell command"), + BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"), + BLTIN("exit" , builtin_exit , NULL), +#if ENABLE_HUSH_EXPORT + BLTIN("export" , builtin_export , "Set environment variables"), +#endif +#if ENABLE_HUSH_JOB + BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"), +#endif +#if ENABLE_HUSH_GETOPTS + BLTIN("getopts" , builtin_getopts , NULL), +#endif +#if ENABLE_HUSH_HELP + BLTIN("help" , builtin_help , NULL), +#endif +#if MAX_HISTORY && ENABLE_FEATURE_EDITING + BLTIN("history" , builtin_history , "Show history"), +#endif +#if ENABLE_HUSH_JOB + BLTIN("jobs" , builtin_jobs , "List jobs"), +#endif +#if ENABLE_HUSH_KILL + BLTIN("kill" , builtin_kill , "Send signals to processes"), +#endif +#if ENABLE_HUSH_LOCAL + BLTIN("local" , builtin_local , "Set local variables"), +#endif +#if ENABLE_HUSH_MEMLEAK + BLTIN("memleak" , builtin_memleak , NULL), +#endif +#if ENABLE_HUSH_READ + BLTIN("read" , builtin_read , "Input into variable"), +#endif +#if ENABLE_HUSH_READONLY + BLTIN("readonly" , builtin_readonly, "Make variables read-only"), +#endif +#if ENABLE_HUSH_FUNCTIONS + BLTIN("return" , builtin_return , "Return from function"), +#endif +#if ENABLE_HUSH_SET + BLTIN("set" , builtin_set , "Set positional parameters"), +#endif + BLTIN("shift" , builtin_shift , "Shift positional parameters"), +#if BASH_SOURCE + BLTIN("source" , builtin_source , NULL), +#endif +#if ENABLE_HUSH_TIMES + BLTIN("times" , builtin_times , NULL), +#endif +#if ENABLE_HUSH_TRAP + BLTIN("trap" , builtin_trap , "Trap signals"), +#endif + BLTIN("true" , builtin_true , NULL), +#if ENABLE_HUSH_TYPE + BLTIN("type" , builtin_type , "Show command type"), +#endif +#if ENABLE_HUSH_ULIMIT + BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"), +#endif +#if ENABLE_HUSH_UMASK + BLTIN("umask" , builtin_umask , "Set file creation mask"), +#endif +#if ENABLE_HUSH_UNSET + BLTIN("unset" , builtin_unset , "Unset variables"), +#endif +#if ENABLE_HUSH_WAIT + BLTIN("wait" , builtin_wait , "Wait for process to finish"), +#endif +}; +/* These builtins won't be used if we are on NOMMU and need to re-exec + * (it's cheaper to run an external program in this case): + */ +static const struct built_in_command bltins2[] ALIGN_PTR = { +#if ENABLE_HUSH_TEST + BLTIN("[" , builtin_test , NULL), +#endif +#if BASH_TEST2 + BLTIN("[[" , builtin_test , NULL), +#endif +#if ENABLE_HUSH_ECHO + BLTIN("echo" , builtin_echo , NULL), +#endif +#if ENABLE_HUSH_PRINTF + BLTIN("printf" , builtin_printf , NULL), +#endif + BLTIN("pwd" , builtin_pwd , NULL), +#if ENABLE_HUSH_TEST + BLTIN("test" , builtin_test , NULL), +#endif +}; + + +/* Debug printouts. + */ +#if HUSH_DEBUG >= 2 +/* prevent disasters with G.debug_indent < 0 */ +# define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "") +# define debug_enter() (G.debug_indent++) +# define debug_leave() (G.debug_indent--) +#else +# define indent() ((void)0) +# define debug_enter() ((void)0) +# define debug_leave() ((void)0) +#endif + +#ifndef debug_printf +# define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_parse +# define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_heredoc +# define debug_printf_heredoc(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_exec +#define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_env +# define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_jobs +# define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__)) +# define DEBUG_JOBS 1 +#else +# define DEBUG_JOBS 0 +#endif + +#ifndef debug_printf_expand +# define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__)) +# define DEBUG_EXPAND 1 +#else +# define DEBUG_EXPAND 0 +#endif + +#ifndef debug_printf_varexp +# define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_glob +# define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__)) +# define DEBUG_GLOB 1 +#else +# define DEBUG_GLOB 0 +#endif + +#ifndef debug_printf_redir +# define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_list +# define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_subst +# define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_prompt +# define debug_printf_prompt(...) (indent(), fdprintf(2, __VA_ARGS__)) +#endif + +#ifndef debug_printf_clean +# define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__)) +# define DEBUG_CLEAN 1 +#else +# define DEBUG_CLEAN 0 +#endif + +#if DEBUG_EXPAND +static void debug_print_strings(const char *prefix, char **vv) +{ + indent(); + fdprintf(2, "%s:\n", prefix); + while (*vv) + fdprintf(2, " '%s'\n", *vv++); +} +#else +# define debug_print_strings(prefix, vv) ((void)0) +#endif + + +/* Leak hunting. Use hush_leaktool.sh for post-processing. + */ +#if LEAK_HUNTING +static void *xxmalloc(int lineno, size_t size) +{ + void *ptr = xmalloc((size + 0xff) & ~0xff); + fdprintf(2, "line %d: malloc %p\n", lineno, ptr); + return ptr; +} +static void *xxrealloc(int lineno, void *ptr, size_t size) +{ + ptr = xrealloc(ptr, (size + 0xff) & ~0xff); + fdprintf(2, "line %d: realloc %p\n", lineno, ptr); + return ptr; +} +static char *xxstrdup(int lineno, const char *str) +{ + char *ptr = xstrdup(str); + fdprintf(2, "line %d: strdup %p\n", lineno, ptr); + return ptr; +} +static void xxfree(void *ptr) +{ + fdprintf(2, "free %p\n", ptr); + free(ptr); +} +# define xmalloc(s) xxmalloc(__LINE__, s) +# define xrealloc(p, s) xxrealloc(__LINE__, p, s) +# define xstrdup(s) xxstrdup(__LINE__, s) +# define free(p) xxfree(p) +#endif + + +/* Syntax and runtime errors. They always abort scripts. + * In interactive use they usually discard unparsed and/or unexecuted commands + * and return to the prompt. + * HUSH_DEBUG >= 2 prints line number in this file where it was detected. + */ +#if HUSH_DEBUG < 2 +# define msg_and_die_if_script(lineno, ...) msg_and_die_if_script(__VA_ARGS__) +# define syntax_error(lineno, msg) syntax_error(msg) +# define syntax_error_at(lineno, msg) syntax_error_at(msg) +# define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch) +# define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s) +# define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch) +#endif + +static void die_if_script(void) +{ + if (!G_interactive_fd) { + if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */ + xfunc_error_retval = G.last_exitcode; + xfunc_die(); + } +} + +static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...) +{ + va_list p; + +#if HUSH_DEBUG >= 2 + bb_error_msg("hush.c:%u", lineno); +#endif + va_start(p, fmt); + bb_verror_msg(fmt, p, NULL); + va_end(p); + die_if_script(); +} + +static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg) +{ + if (msg) + bb_error_msg("syntax error: %s", msg); + else + bb_simple_error_msg("syntax error"); + die_if_script(); +} + +static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg) +{ + bb_error_msg("syntax error at '%s'", msg); + die_if_script(); +} + +static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s) +{ + bb_error_msg("syntax error: unterminated %s", s); +//? source4.tests fails: in bash, echo ${^} in script does not terminate the script +// die_if_script(); +} + +static void syntax_error_unterm_ch(unsigned lineno, char ch) +{ + char msg[2] = { ch, '\0' }; + syntax_error_unterm_str(lineno, msg); +} + +static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch) +{ + char msg[2]; + msg[0] = ch; + msg[1] = '\0'; +#if HUSH_DEBUG >= 2 + bb_error_msg("hush.c:%u", lineno); +#endif + bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg); + die_if_script(); +} + +#if HUSH_DEBUG < 2 +# undef msg_and_die_if_script +# undef syntax_error +# undef syntax_error_at +# undef syntax_error_unterm_ch +# undef syntax_error_unterm_str +# undef syntax_error_unexpected_ch +#else +# define msg_and_die_if_script(...) msg_and_die_if_script(__LINE__, __VA_ARGS__) +# define syntax_error(msg) syntax_error(__LINE__, msg) +# define syntax_error_at(msg) syntax_error_at(__LINE__, msg) +# define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch) +# define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s) +# define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch) +#endif + + +/* Utility functions + */ +/* Replace each \x with x in place, return ptr past NUL. */ +static char *unbackslash(char *src) +{ + char *dst = src = strchrnul(src, '\'); + while (1) { + if (*src == '\') { + src++; + if (*src != '\0') { + /* \x -> x */ + *dst++ = *src++; + continue; + } + /* else: "<nul>". Do not delete this backslash. + * Testcase: eval 'echo ok' + */ + *dst++ = '\'; + /* fallthrough */ + } + if ((*dst++ = *src++) == '\0') + break; + } + return dst; +} + +static char **add_strings_to_strings(char **strings, char **add, int need_to_dup) +{ + int i; + unsigned count1; + unsigned count2; + char **v; + + v = strings; + count1 = 0; + if (v) { + while (*v) { + count1++; + v++; + } + } + count2 = 0; + v = add; + while (*v) { + count2++; + v++; + } + v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*)); + v[count1 + count2] = NULL; + i = count2; + while (--i >= 0) + v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]); + return v; +} +#if LEAK_HUNTING +static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup) +{ + char **ptr = add_strings_to_strings(strings, add, need_to_dup); + fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr); + return ptr; +} +#define add_strings_to_strings(strings, add, need_to_dup) \ + xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup) +#endif + +/* Note: takes ownership of "add" ptr (it is not strdup'ed) */ +static char **add_string_to_strings(char **strings, char *add) +{ + char *v[2]; + v[0] = add; + v[1] = NULL; + return add_strings_to_strings(strings, v, /*dup:*/ 0); +} +#if LEAK_HUNTING +static char **xx_add_string_to_strings(int lineno, char **strings, char *add) +{ + char **ptr = add_string_to_strings(strings, add); + fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr); + return ptr; +} +#define add_string_to_strings(strings, add) \ + xx_add_string_to_strings(__LINE__, strings, add) +#endif + +static void free_strings(char **strings) +{ + char **v; + + if (!strings) + return; + v = strings; + while (*v) { + free(*v); + v++; + } + free(strings); +} + +static int dup_CLOEXEC(int fd, int avoid_fd) +{ + int newfd; + repeat: + newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1); + if (newfd >= 0) { + if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */ + fcntl(newfd, F_SETFD, FD_CLOEXEC); + } else { /* newfd < 0 */ + if (errno == EBUSY) + goto repeat; + if (errno == EINTR) + goto repeat; + } + return newfd; +} + +static int xdup_CLOEXEC_and_close(int fd, int avoid_fd) +{ + int newfd; + repeat: + newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1); + if (newfd < 0) { + if (errno == EBUSY) + goto repeat; + if (errno == EINTR) + goto repeat; + /* fd was not open? */ + if (errno == EBADF) + return fd; + xfunc_die(); + } + if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */ + fcntl(newfd, F_SETFD, FD_CLOEXEC); + close(fd); + return newfd; +} + + +/* Manipulating HFILEs */ +static HFILE *hfopen(const char *name) +{ + HFILE *fp; + int fd; + + fd = STDIN_FILENO; + if (name) { + fd = open(name, O_RDONLY | O_CLOEXEC); + if (fd < 0) + return NULL; + if (O_CLOEXEC == 0) /* ancient libc */ + close_on_exec_on(fd); + } + + fp = xmalloc(sizeof(*fp)); + if (name == NULL) + G.HFILE_stdin = fp; + fp->fd = fd; + fp->cur = fp->end = fp->buf; + fp->next_hfile = G.HFILE_list; + G.HFILE_list = fp; + return fp; +} +static void hfclose(HFILE *fp) +{ + HFILE **pp = &G.HFILE_list; + while (*pp) { + HFILE *cur = *pp; + if (cur == fp) { + *pp = cur->next_hfile; + break; + } + pp = &cur->next_hfile; + } + if (fp->fd >= 0) + close(fp->fd); + free(fp); +} +static int refill_HFILE_and_getc(HFILE *fp) +{ + int n; + + if (fp->fd < 0) { + /* Already saw EOF */ + return EOF; + } +#if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_EDITING + /* If user presses ^C, read() restarts after SIGINT (we use SA_RESTART). + * IOW: ^C will not immediately stop line input. + * But poll() is different: it does NOT restart after signals. + */ + if (fp == G.HFILE_stdin) { + struct pollfd pfd[1]; + pfd[0].fd = fp->fd; + pfd[0].events = POLLIN; + n = poll(pfd, 1, -1); + if (n < 0 + /*&& errno == EINTR - assumed true */ + && sigismember(&G.pending_set, SIGINT) + ) { + return '\0'; + } + } +#else +/* if FEATURE_EDITING=y, we do not use this routine for interactive input */ +#endif + /* Try to buffer more input */ + n = safe_read(fp->fd, fp->buf, sizeof(fp->buf)); + if (n < 0) { + bb_simple_perror_msg("read error"); + n = 0; + } + fp->cur = fp->buf; + fp->end = fp->buf + n; + if (n == 0) { + /* EOF/error */ + close(fp->fd); + fp->fd = -1; + return EOF; + } + return (unsigned char)(*fp->cur++); +} +/* Inlined for common case of non-empty buffer. + */ +static ALWAYS_INLINE int hfgetc(HFILE *fp) +{ + if (fp->cur < fp->end) + return (unsigned char)(*fp->cur++); + /* Buffer empty */ + return refill_HFILE_and_getc(fp); +} +static int move_HFILEs_on_redirect(int fd, int avoid_fd) +{ + HFILE *fl = G.HFILE_list; + while (fl) { + if (fd == fl->fd) { + /* We use it only on script files, they are all CLOEXEC */ + fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd); + debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd); + return 1; /* "found and moved" */ + } + fl = fl->next_hfile; + } +#if ENABLE_HUSH_MODE_X + if (G.x_mode_fd > 0 && fd == G.x_mode_fd) { + G.x_mode_fd = xdup_CLOEXEC_and_close(fd, avoid_fd); + return 1; /* "found and moved" */ + } +#endif + return 0; /* "not in the list" */ +} +#if ENABLE_FEATURE_SH_STANDALONE && BB_MMU +static void close_all_HFILE_list(void) +{ + HFILE *fl = G.HFILE_list; + while (fl) { + /* hfclose would also free HFILE object. + * It is disastrous if we share memory with a vforked parent. + * I'm not sure we never come here after vfork. + * Therefore just close fd, nothing more. + * + * ">" instead of ">=": we don't close fd#0, + * interactive shell uses hfopen(NULL) as stdin input + * which has fl->fd == 0, but fd#0 gets redirected in pipes. + * If we'd close it here, then e.g. interactive "set | sort" + * with NOFORKed sort, would have sort's input fd closed. + */ + if (fl->fd > 0) + /*hfclose(fl); - unsafe */ + close(fl->fd); + fl = fl->next_hfile; + } +} +#endif +static int fd_in_HFILEs(int fd) +{ + HFILE *fl = G.HFILE_list; + while (fl) { + if (fl->fd == fd) + return 1; + fl = fl->next_hfile; + } + return 0; +} + + +/* Helpers for setting new $n and restoring them back + */ +typedef struct save_arg_t { + char *sv_argv0; + char **sv_g_argv; + int sv_g_argc; + IF_HUSH_SET(smallint sv_g_malloced;) +} save_arg_t; + +static void save_and_replace_G_args(save_arg_t *sv, char **argv) +{ + sv->sv_argv0 = argv[0]; + sv->sv_g_argv = G.global_argv; + sv->sv_g_argc = G.global_argc; + IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;) + + argv[0] = G.global_argv[0]; /* retain $0 */ + G.global_argv = argv; + IF_HUSH_SET(G.global_args_malloced = 0;) + + G.global_argc = 1 + string_array_len(argv + 1); +} + +static void restore_G_args(save_arg_t *sv, char **argv) +{ +#if ENABLE_HUSH_SET + if (G.global_args_malloced) { + /* someone ran "set -- arg1 arg2 ...", undo */ + char **pp = G.global_argv; + while (*++pp) /* note: does not free $0 */ + free(*pp); + free(G.global_argv); + } +#endif + argv[0] = sv->sv_argv0; + G.global_argv = sv->sv_g_argv; + G.global_argc = sv->sv_g_argc; + IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;) +} + + +/* Basic theory of signal handling in shell + * ======================================== + * This does not describe what hush does, rather, it is current understanding + * what it _should_ do. If it doesn't, it's a bug. + * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap + * + * Signals are handled only after each pipe ("cmd | cmd | cmd" thing) + * is finished or backgrounded. It is the same in interactive and + * non-interactive shells, and is the same regardless of whether + * a user trap handler is installed or a shell special one is in effect. + * ^C or ^Z from keyboard seems to execute "at once" because it usually + * backgrounds (i.e. stops) or kills all members of currently running + * pipe. + * + * Wait builtin is interruptible by signals for which user trap is set + * or by SIGINT in interactive shell. + * + * Trap handlers will execute even within trap handlers. (right?) + * + * User trap handlers are forgotten when subshell ("(cmd)") is entered, + * except for handlers set to '' (empty string). + * + * If job control is off, backgrounded commands ("cmd &") + * have SIGINT, SIGQUIT set to SIG_IGN. + * + * Commands which are run in command substitution ("`cmd`") + * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN. + * + * Ordinary commands have signals set to SIG_IGN/DFL as inherited + * by the shell from its parent. + * + * Signals which differ from SIG_DFL action + * (note: child (i.e., [v]forked) shell is not an interactive shell): + * + * SIGQUIT: ignore + * SIGTERM (interactive): ignore + * SIGHUP (interactive): + * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit + * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore + * Note that ^Z is handled not by trapping SIGTSTP, but by seeing + * that all pipe members are stopped. Try this in bash: + * while :; do :; done - ^Z does not background it + * (while :; do :; done) - ^Z backgrounds it + * SIGINT (interactive): wait for last pipe, ignore the rest + * of the command line, show prompt. NB: ^C does not send SIGINT + * to interactive shell while shell is waiting for a pipe, + * since shell is bg'ed (is not in foreground process group). + * Example 1: this waits 5 sec, but does not execute ls: + * "echo $$; sleep 5; ls -l" + "kill -INT <pid>" + * Example 2: this does not wait and does not execute ls: + * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>" + * Example 3: this does not wait 5 sec, but executes ls: + * "sleep 5; ls -l" + press ^C + * Example 4: this does not wait and does not execute ls: + * "sleep 5 & wait; ls -l" + press ^C + * + * (What happens to signals which are IGN on shell start?) + * (What happens with signal mask on shell start?) + * + * Old implementation + * ================== + * We use in-kernel pending signal mask to determine which signals were sent. + * We block all signals which we don't want to take action immediately, + * i.e. we block all signals which need to have special handling as described + * above, and all signals which have traps set. + * After each pipe execution, we extract any pending signals via sigtimedwait() + * and act on them. + * + * unsigned special_sig_mask: a mask of such "special" signals + * sigset_t blocked_set: current blocked signal set + * + * "trap - SIGxxx": + * clear bit in blocked_set unless it is also in special_sig_mask + * "trap 'cmd' SIGxxx": + * set bit in blocked_set (even if 'cmd' is '') + * after [v]fork, if we plan to be a shell: + * unblock signals with special interactive handling + * (child shell is not interactive), + * unset all traps except '' (note: regardless of child shell's type - {}, (), etc) + * after [v]fork, if we plan to exec: + * POSIX says fork clears pending signal mask in child - no need to clear it. + * Restore blocked signal set to one inherited by shell just prior to exec. + * + * Note: as a result, we do not use signal handlers much. The only uses + * are to count SIGCHLDs + * and to restore tty pgrp on signal-induced exit. + * + * Note 2 (compat): + * Standard says "When a subshell is entered, traps that are not being ignored + * are set to the default actions". bash interprets it so that traps which + * are set to '' (ignore) are NOT reset to defaults. We do the same. + * + * Problem: the above approach makes it unwieldy to catch signals while + * we are in read builtin, or while we read commands from stdin: + * masked signals are not visible! + * + * New implementation + * ================== + * We record each signal we are interested in by installing signal handler + * for them - a bit like emulating kernel pending signal mask in userspace. + * We are interested in: signals which need to have special handling + * as described above, and all signals which have traps set. + * Signals are recorded in pending_set. + * After each pipe execution, we extract any pending signals + * and act on them. + * + * unsigned special_sig_mask: a mask of shell-special signals. + * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp. + * char *traps[sig] if trap for sig is set (even if it's ''). + * sigset_t pending_set: set of sigs we received. + * + * "trap - SIGxxx": + * if sig is in special_sig_mask, set handler back to: + * record_pending_signo, or to IGN if it's a tty stop signal + * if sig is in fatal_sig_mask, set handler back to sigexit. + * else: set handler back to SIG_DFL + * "trap 'cmd' SIGxxx": + * set handler to record_pending_signo. + * "trap '' SIGxxx": + * set handler to SIG_IGN. + * after [v]fork, if we plan to be a shell: + * set signals with special interactive handling to SIG_DFL + * (because child shell is not interactive), + * unset all traps except '' (note: regardless of child shell's type - {}, (), etc) + * after [v]fork, if we plan to exec: + * POSIX says fork clears pending signal mask in child - no need to clear it. + * + * To make wait builtin interruptible, we handle SIGCHLD as special signal, + * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it. + * + * Note (compat): + * Standard says "When a subshell is entered, traps that are not being ignored + * are set to the default actions". bash interprets it so that traps which + * are set to '' (ignore) are NOT reset to defaults. We do the same. + */ +enum { + SPECIAL_INTERACTIVE_SIGS = 0 + | (1 << SIGTERM) + | (1 << SIGINT) + | (1 << SIGHUP) + , + SPECIAL_JOBSTOP_SIGS = 0 +#if ENABLE_HUSH_JOB + | (1 << SIGTTIN) + | (1 << SIGTTOU) + | (1 << SIGTSTP) +#endif + , +}; + +static void record_pending_signo(int sig) +{ + sigaddset(&G.pending_set, sig); +#if ENABLE_HUSH_FAST + if (sig == SIGCHLD) { + G.count_SIGCHLD++; +//bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); + } +#endif +} + +static sighandler_t install_sighandler(int sig, sighandler_t handler) +{ + struct sigaction old_sa; + + /* We could use signal() to install handlers... almost: + * except that we need to mask ALL signals while handlers run. + * I saw signal nesting in strace, race window isn't small. + * SA_RESTART is also needed, but in Linux, signal() + * sets SA_RESTART too. + */ + /* memset(&G.sa, 0, sizeof(G.sa)); - already done */ + /* sigfillset(&G.sa.sa_mask); - already done */ + /* G.sa.sa_flags = SA_RESTART; - already done */ + G.sa.sa_handler = handler; + sigaction(sig, &G.sa, &old_sa); + return old_sa.sa_handler; +} + +static void hush_exit(int exitcode) NORETURN; + +static void restore_ttypgrp_and__exit(void) NORETURN; +static void restore_ttypgrp_and__exit(void) +{ + /* xfunc has failed! die die die */ + /* no EXIT traps, this is an escape hatch! */ + G.exiting = 1; + hush_exit(xfunc_error_retval); +} + +#if ENABLE_HUSH_JOB + +/* Needed only on some libc: + * It was observed that on exit(), fgetc'ed buffered data + * gets "unwound" via lseek(fd, -NUM, SEEK_CUR). + * With the net effect that even after fork(), not vfork(), + * exit() in NOEXECed applet in "sh SCRIPT": + * noexec_applet_here + * echo END_OF_SCRIPT + * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT". + * This makes "echo END_OF_SCRIPT" executed twice. + * Similar problems can be seen with msg_and_die_if_script() -> xfunc_die() + * and in `cmd` handling. + * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit(): + */ +static void fflush_and__exit(void) NORETURN; +static void fflush_and__exit(void) +{ + fflush_all(); + _exit(xfunc_error_retval); +} + +/* After [v]fork, in child: do not restore tty pgrp on xfunc death */ +# define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit) +/* After [v]fork, in parent: restore tty pgrp on xfunc death */ +# define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit) + +/* Restores tty foreground process group, and exits. + * May be called as signal handler for fatal signal + * (will resend signal to itself, producing correct exit state) + * or called directly with -EXITCODE. + * We also call it if xfunc is exiting. + */ +static void sigexit(int sig) NORETURN; +static void sigexit(int sig) +{ + /* Careful: we can end up here after [v]fork. Do not restore + * tty pgrp then, only top-level shell process does that */ + if (G_saved_tty_pgrp && getpid() == G.root_pid) { + /* Disable all signals: job control, SIGPIPE, etc. + * Mostly paranoid measure, to prevent infinite SIGTTOU. + */ + sigprocmask_allsigs(SIG_BLOCK); + tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp); + } + + /* Not a signal, just exit */ + if (sig <= 0) + _exit(- sig); + + kill_myself_with_sig(sig); /* does not return */ +} +#else + +# define disable_restore_tty_pgrp_on_exit() ((void)0) +# define enable_restore_tty_pgrp_on_exit() ((void)0) + +#endif + +static sighandler_t pick_sighandler(unsigned sig) +{ + sighandler_t handler = SIG_DFL; + if (sig < sizeof(unsigned)*8) { + unsigned sigmask = (1 << sig); + +#if ENABLE_HUSH_JOB + /* is sig fatal? */ + if (G_fatal_sig_mask & sigmask) + handler = sigexit; + else +#endif + /* sig has special handling? */ + if (G.special_sig_mask & sigmask) { + handler = record_pending_signo; + /* TTIN/TTOU/TSTP can't be set to record_pending_signo + * in order to ignore them: they will be raised + * in an endless loop when we try to do some + * terminal ioctls! We do have to _ignore_ these. + */ + if (SPECIAL_JOBSTOP_SIGS & sigmask) + handler = SIG_IGN; + } + } + return handler; +} + +/* Restores tty foreground process group, and exits. */ +static void hush_exit(int exitcode) +{ +#if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT + save_history(G.line_input_state); /* may be NULL */ +#endif + + fflush_all(); + if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) { + char *argv[3]; + /* argv[0] is unused */ + argv[1] = xstrdup(G_traps[0]); /* copy, since EXIT trap handler may modify G_traps[0] */ + argv[2] = NULL; + G.exiting = 1; /* prevent EXIT trap recursion */ + /* Note: G_traps[0] is not cleared! + * "trap" will still show it, if executed + * in the handler */ + builtin_eval(argv); + } + +#if ENABLE_FEATURE_CLEAN_UP + { + struct variable *cur_var; + if (G.cwd != bb_msg_unknown) + free((char*)G.cwd); + cur_var = G.top_var; + while (cur_var) { + struct variable *tmp = cur_var; + if (!cur_var->max_len) + free(cur_var->varstr); + cur_var = cur_var->next; + free(tmp); + } + } +#endif + + fflush_all(); +#if ENABLE_HUSH_JOB + sigexit(- (exitcode & 0xff)); +#else + _exit(exitcode); +#endif +} + +//TODO: return a mask of ALL handled sigs? +static int check_and_run_traps(void) +{ + int last_sig = 0; + + while (1) { + int sig; + + if (sigisemptyset(&G.pending_set)) + break; + sig = 0; + do { + sig++; + if (sigismember(&G.pending_set, sig)) { + sigdelset(&G.pending_set, sig); + goto got_sig; + } + } while (sig < NSIG); + break; + got_sig: +#if ENABLE_HUSH_TRAP + if (G_traps && G_traps[sig]) { + debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]); + if (G_traps[sig][0]) { + /* We have user-defined handler */ + smalluint save_rcode; + int save_pre; + char *argv[3]; + /* argv[0] is unused */ + argv[1] = xstrdup(G_traps[sig]); + /* why strdup? trap can modify itself: trap 'trap "echo oops" INT' INT */ + argv[2] = NULL; + save_pre = G.pre_trap_exitcode; + G.pre_trap_exitcode = save_rcode = G.last_exitcode; + builtin_eval(argv); + free(argv[1]); + G.pre_trap_exitcode = save_pre; + G.last_exitcode = save_rcode; +# if ENABLE_HUSH_FUNCTIONS + if (G.return_exitcode >= 0) { + debug_printf_exec("trap exitcode:%d\n", G.return_exitcode); + G.last_exitcode = G.return_exitcode; + } +# endif + last_sig = sig; + } /* else: "" trap, ignoring signal */ + continue; + } +#endif + /* not a trap: special action */ + switch (sig) { + case SIGINT: + debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig); + G.flag_SIGINT = 1; + last_sig = sig; + break; +#if ENABLE_HUSH_JOB + case SIGHUP: { +//TODO: why are we doing this? ash and dash don't do this, +//they have no handler for SIGHUP at all, +//they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups + struct pipe *job; + debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig); + /* bash is observed to signal whole process groups, + * not individual processes */ + for (job = G.job_list; job; job = job->next) { + if (job->pgrp <= 0) + continue; + debug_printf_exec("HUPing pgrp %d\n", job->pgrp); + if (kill(- job->pgrp, SIGHUP) == 0) + kill(- job->pgrp, SIGCONT); + } + sigexit(SIGHUP); + } +#endif +#if ENABLE_HUSH_FAST + case SIGCHLD: + debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig); + G.count_SIGCHLD++; +//bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); + /* Note: + * We don't do 'last_sig = sig' here -> NOT returning this sig. + * This simplifies wait builtin a bit. + */ + break; +#endif + default: /* ignored: */ + debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig); + /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */ + /* Note: + * We don't do 'last_sig = sig' here -> NOT returning this sig. + * Example: wait is not interrupted by TERM + * in interactive shell, because TERM is ignored. + */ + break; + } + } + return last_sig; +} + + +static const char *get_cwd(int force) +{ + if (force || G.cwd == NULL) { + /* xrealloc_getcwd_or_warn(arg) calls free(arg), + * we must not try to free(bb_msg_unknown) */ + if (G.cwd == bb_msg_unknown) + G.cwd = NULL; + G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd); + if (!G.cwd) + G.cwd = bb_msg_unknown; + } + return G.cwd; +} + + +/* + * Shell and environment variable support + */ +static struct variable **get_ptr_to_local_var(const char *name, unsigned len) +{ + struct variable **pp; + struct variable *cur; + + pp = &G.top_var; + while ((cur = *pp) != NULL) { + if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') + return pp; + pp = &cur->next; + } + return NULL; +} + +static const char* FAST_FUNC get_local_var_value(const char *name) +{ + struct variable **vpp; + unsigned len = strlen(name); + + if (G.expanded_assignments) { + char **cpp = G.expanded_assignments; + while (*cpp) { + char *cp = *cpp; + if (strncmp(cp, name, len) == 0 && cp[len] == '=') + return cp + len + 1; + cpp++; + } + } + + vpp = get_ptr_to_local_var(name, len); + if (vpp) + return (*vpp)->varstr + len + 1; + + if (strcmp(name, "PPID") == 0) + return utoa(G.root_ppid); + // bash compat: UID? EUID? +#if ENABLE_HUSH_RANDOM_SUPPORT + if (strcmp(name, "RANDOM") == 0) + return utoa(next_random(&G.random_gen)); +#endif +#if ENABLE_HUSH_LINENO_VAR + if (strcmp(name, "LINENO") == 0) + return utoa(G.execute_lineno); +#endif +#if BASH_EPOCH_VARS + { + const char *fmt = NULL; + if (strcmp(name, "EPOCHSECONDS") == 0) + fmt = "%llu"; + else if (strcmp(name, "EPOCHREALTIME") == 0) + fmt = "%llu.%06u"; + if (fmt) { + struct timeval tv; + xgettimeofday(&tv); + sprintf(G.epoch_buf, fmt, (unsigned long long)tv.tv_sec, + (unsigned)tv.tv_usec); + return G.epoch_buf; + } + } +#endif + return NULL; +} + +#if ENABLE_HUSH_GETOPTS +static void handle_changed_special_names(const char *name, unsigned name_len) +{ + if (name_len == 6) { + if (strncmp(name, "OPTIND", 6) == 0) { + G.getopt_count = 0; + return; + } + } +} +#else +/* Do not even bother evaluating arguments */ +# define handle_changed_special_names(...) ((void)0) +#endif + +/* str holds "NAME=VAL" and is expected to be malloced. + * We take ownership of it. + */ +#define SETFLAG_EXPORT (1 << 0) +#define SETFLAG_UNEXPORT (1 << 1) +#define SETFLAG_MAKE_RO (1 << 2) +#define SETFLAG_VARLVL_SHIFT 3 +static int set_local_var(char *str, unsigned flags) +{ + struct variable **cur_pp; + struct variable *cur; + char *free_me = NULL; + char *eq_sign; + int name_len; + int retval; + unsigned local_lvl = (flags >> SETFLAG_VARLVL_SHIFT); + + eq_sign = strchr(str, '='); + if (HUSH_DEBUG && !eq_sign) + bb_simple_error_msg_and_die("BUG in setvar"); + + name_len = eq_sign - str + 1; /* including '=' */ + cur_pp = &G.top_var; + while ((cur = *cur_pp) != NULL) { + if (strncmp(cur->varstr, str, name_len) != 0) { + cur_pp = &cur->next; + continue; + } + + /* We found an existing var with this name */ + if (cur->flg_read_only) { + bb_error_msg("%s: readonly variable", str); + free(str); +//NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1, +//but export per se succeeds (does put the var in env). We don't mimic that. + return -1; + } + if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ? + debug_printf_env("%s: unsetenv '%s'\n", __func__, str); + *eq_sign = '\0'; + unsetenv(str); + *eq_sign = '='; + } + if (cur->var_nest_level < local_lvl) { + /* bash 3.2.33(1) and exported vars: + * # export z=z + * # f() { local z=a; env | grep ^z; } + * # f + * z=a + * # env | grep ^z + * z=z + */ + if (cur->flg_export) + flags |= SETFLAG_EXPORT; + /* New variable is local ("local VAR=VAL" or + * "VAR=VAL cmd") + * and existing one is global, or local + * on a lower level that new one. + * Remove it from global variable list: + */ + *cur_pp = cur->next; + if (G.shadowed_vars_pp) { + /* Save in "shadowed" list */ + debug_printf_env("shadowing %s'%s'/%u by '%s'/%u\n", + cur->flg_export ? "exported " : "", + cur->varstr, cur->var_nest_level, str, local_lvl + ); + cur->next = *G.shadowed_vars_pp; + *G.shadowed_vars_pp = cur; + } else { + /* Came from pseudo_exec_argv(), no need to save: delete it */ + debug_printf_env("shadow-deleting %s'%s'/%u by '%s'/%u\n", + cur->flg_export ? "exported " : "", + cur->varstr, cur->var_nest_level, str, local_lvl + ); + if (cur->max_len == 0) /* allocated "VAR=VAL"? */ + free_me = cur->varstr; /* then free it later */ + free(cur); + } + break; + } + + if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) { + debug_printf_env("assignement '%s' does not change anything\n", str); + free_and_exp: + free(str); + goto exp; + } + + /* Replace the value in the found "struct variable" */ + if (cur->max_len != 0) { + if (cur->max_len >= strnlen(str, cur->max_len + 1)) { + /* This one is from startup env, reuse space */ + debug_printf_env("reusing startup env for '%s'\n", str); + strcpy(cur->varstr, str); + goto free_and_exp; + } + /* Can't reuse */ + cur->max_len = 0; + goto set_str_and_exp; + } + /* max_len == 0 signifies "malloced" var, which we can + * (and have to) free. But we can't free(cur->varstr) here: + * if cur->flg_export is 1, it is in the environment. + * We should either unsetenv+free, or wait until putenv, + * then putenv(new)+free(old). + */ + free_me = cur->varstr; + goto set_str_and_exp; + } + + /* Not found or shadowed - create new variable struct */ + debug_printf_env("%s: alloc new var '%s'/%u\n", __func__, str, local_lvl); + cur = xzalloc(sizeof(*cur)); + cur->var_nest_level = local_lvl; + cur->next = *cur_pp; + *cur_pp = cur; + + set_str_and_exp: + cur->varstr = str; + exp: +#if !BB_MMU || ENABLE_HUSH_READONLY + if (flags & SETFLAG_MAKE_RO) { + cur->flg_read_only = 1; + } +#endif + if (flags & SETFLAG_EXPORT) + cur->flg_export = 1; + retval = 0; + if (cur->flg_export) { + if (flags & SETFLAG_UNEXPORT) { + cur->flg_export = 0; + /* unsetenv was already done */ + } else { + debug_printf_env("%s: putenv '%s'/%u\n", __func__, cur->varstr, cur->var_nest_level); + retval = putenv(cur->varstr); + /* fall through to "free(free_me)" - + * only now we can free old exported malloced string + */ + } + } + free(free_me); + + handle_changed_special_names(cur->varstr, name_len - 1); + + return retval; +} + +static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val) +{ + char *var = xasprintf("%s=%s", name, val); + set_local_var(var, /*flag:*/ 0); +} + +/* Used at startup and after each cd */ +static void set_pwd_var(unsigned flag) +{ + set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag); +} + +#if ENABLE_HUSH_UNSET || ENABLE_HUSH_GETOPTS +static int unset_local_var_len(const char *name, int name_len) +{ + struct variable *cur; + struct variable **cur_pp; + + cur_pp = &G.top_var; + while ((cur = *cur_pp) != NULL) { + if (strncmp(cur->varstr, name, name_len) == 0 + && cur->varstr[name_len] == '=' + ) { + if (cur->flg_read_only) { + bb_error_msg("%s: readonly variable", name); + return EXIT_FAILURE; + } + + *cur_pp = cur->next; + debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr); + bb_unsetenv(cur->varstr); + if (!cur->max_len) + free(cur->varstr); + free(cur); + + break; + } + cur_pp = &cur->next; + } + + /* Handle "unset LINENO" et al even if did not find the variable to unset */ + handle_changed_special_names(name, name_len); + + return EXIT_SUCCESS; +} + +static int unset_local_var(const char *name) +{ + return unset_local_var_len(name, strlen(name)); +} +#endif + + +/* + * Helpers for "var1=val1 var2=val2 cmd" feature + */ +static void add_vars(struct variable *var) +{ + struct variable *next; + + while (var) { + next = var->next; + var->next = G.top_var; + G.top_var = var; + if (var->flg_export) { + debug_printf_env("%s: restoring exported '%s'/%u\n", __func__, var->varstr, var->var_nest_level); + putenv(var->varstr); + } else { + debug_printf_env("%s: restoring variable '%s'/%u\n", __func__, var->varstr, var->var_nest_level); + } + var = next; + } +} + +/* We put strings[i] into variable table and possibly putenv them. + * If variable is read only, we can free the strings[i] + * which attempts to overwrite it. + * The strings[] vector itself is freed. + */ +static void set_vars_and_save_old(char **strings) +{ + char **s; + + if (!strings) + return; + + s = strings; + while (*s) { + struct variable *var_p; + struct variable **var_pp; + char *eq; + + eq = strchr(*s, '='); + if (HUSH_DEBUG && !eq) + bb_simple_error_msg_and_die("BUG in varexp4"); + var_pp = get_ptr_to_local_var(*s, eq - *s); + if (var_pp) { + var_p = *var_pp; + if (var_p->flg_read_only) { + char **p; + bb_error_msg("%s: readonly variable", *s); + /* + * "VAR=V BLTIN" unsets VARs after BLTIN completes. + * If VAR is readonly, leaving it in the list + * after asssignment error (msg above) + * causes doubled error message later, on unset. + */ + debug_printf_env("removing/freeing '%s' element\n", *s); + free(*s); + p = s; + do { *p = p[1]; p++; } while (*p); + goto next; + } + /* below, set_local_var() with nest level will + * "shadow" (remove) this variable from + * global linked list. + */ + } + debug_printf_env("%s: env override '%s'/%u\n", __func__, *s, G.var_nest_level); + set_local_var(*s, (G.var_nest_level << SETFLAG_VARLVL_SHIFT) | SETFLAG_EXPORT); + s++; + next: ; + } + free(strings); +} + + +/* + * Unicode helper + */ +static void reinit_unicode_for_hush(void) +{ + /* Unicode support should be activated even if LANG is set + * _during_ shell execution, not only if it was set when + * shell was started. Therefore, re-check LANG every time: + */ + if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV + || ENABLE_UNICODE_USING_LOCALE + ) { + const char *s = get_local_var_value("LC_ALL"); + if (!s) s = get_local_var_value("LC_CTYPE"); + if (!s) s = get_local_var_value("LANG"); + reinit_unicode(s); + } +} + +/* + * in_str support (strings, and "strings" read from files). + */ + +#if ENABLE_HUSH_INTERACTIVE +/* To test correct lineedit/interactive behavior, type from command line: + * echo $P\ + * \ + * AT\ + * H\ + * \ + * It exercises a lot of corner cases. + */ +static const char *setup_prompt_string(void) +{ + const char *prompt_str; + + debug_printf_prompt("%s promptmode:%d\n", __func__, G.promptmode); + +# if ENABLE_FEATURE_EDITING_FANCY_PROMPT + prompt_str = get_local_var_value(G.promptmode == 0 ? "PS1" : "PS2"); + if (!prompt_str) + prompt_str = ""; +# else + prompt_str = "> "; /* if PS2, else... */ + if (G.promptmode == 0) { /* PS1 */ + /* No fancy prompts supported, (re)generate "CURDIR $ " by hand */ + free(G.PS1); + /* bash uses $PWD value, even if it is set by user. + * It uses current dir only if PWD is unset. + * We always use current dir. */ + prompt_str = G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#'); + } +# endif + debug_printf("prompt_str '%s'\n", prompt_str); + return prompt_str; +} +static int get_user_input(struct in_str *i) +{ +# if ENABLE_FEATURE_EDITING + /* In EDITING case, this function reads next input line, + * saves it in i->p, then returns 1st char of it. + */ + int r; + const char *prompt_str; + + prompt_str = setup_prompt_string(); + for (;;) { + reinit_unicode_for_hush(); + G.flag_SIGINT = 0; + /* buglet: SIGINT will not make new prompt to appear _at once_, + * only after <Enter>. (^C works immediately) */ + r = read_line_input(G.line_input_state, prompt_str, + G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1 + ); + /* read_line_input intercepts ^C, "convert" it to SIGINT */ + if (r == 0) { + raise(SIGINT); + } + check_and_run_traps(); + if (r != 0 && !G.flag_SIGINT) + break; + /* ^C or SIGINT: repeat */ + /* bash prints ^C even on real SIGINT (non-kbd generated) */ + write(STDOUT_FILENO, "^C\n", 3); + G.last_exitcode = 128 | SIGINT; + } + if (r < 0) { + /* EOF/error detected */ + /* ^D on interactive input goes to next line before exiting: */ + write(STDOUT_FILENO, "\n", 1); + i->p = NULL; + i->peek_buf[0] = r = EOF; + return r; + } + i->p = G.user_input_buf; + return (unsigned char)*i->p++; +# else + /* In !EDITING case, this function gets called for every char. + * Buffering happens deeper in the call chain, in hfgetc(i->file). + */ + int r; + + for (;;) { + G.flag_SIGINT = 0; + if (i->last_char == '\0' || i->last_char == '\n') { + const char *prompt_str = setup_prompt_string(); + /* Why check_and_run_traps here? Try this interactively: + * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) & + * $ <[enter], repeatedly...> + * Without check_and_run_traps, handler never runs. + */ + check_and_run_traps(); + fputs_stdout(prompt_str); + fflush_all(); + } + r = hfgetc(i->file); + /* In !ENABLE_FEATURE_EDITING we don't use read_line_input, + * no ^C masking happens during fgetc, no special code for ^C: + * it generates SIGINT as usual. + */ + check_and_run_traps(); + if (r != '\0' && !G.flag_SIGINT) + break; + if (G.flag_SIGINT) { + /* ^C or SIGINT: repeat */ + /* bash prints ^C even on real SIGINT (non-kbd generated) */ + /* kernel prints "^C" itself, just print newline: */ + write(STDOUT_FILENO, "\n", 1); + G.last_exitcode = 128 | SIGINT; + } + } + return r; +# endif +} +/* This is the magic location that prints prompts + * and gets data back from the user */ +static int fgetc_interactive(struct in_str *i) +{ + int ch; + /* If it's interactive stdin, get new line. */ + if (G_interactive_fd && i->file == G.HFILE_stdin) { + /* Returns first char (or EOF), the rest is in i->p[] */ + ch = get_user_input(i); + G.promptmode = 1; /* PS2 */ + debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode); + } else { + /* Not stdin: script file, sourced file, etc */ + do ch = hfgetc(i->file); while (ch == '\0'); + } + return ch; +} +#else /* !INTERACTIVE */ +static ALWAYS_INLINE int fgetc_interactive(struct in_str *i) +{ + int ch; + do ch = hfgetc(i->file); while (ch == '\0'); + return ch; +} +#endif /* !INTERACTIVE */ + +static int i_getch(struct in_str *i) +{ + int ch; + + if (!i->file) { + /* string-based in_str */ + ch = (unsigned char)*i->p; + if (ch != '\0') { + i->p++; + i->last_char = ch; + return ch; + } + return EOF; + } + + /* FILE-based in_str */ + +#if ENABLE_FEATURE_EDITING + /* This can be stdin, check line editing char[] buffer */ + if (i->p && *i->p != '\0') { + ch = (unsigned char)*i->p++; + goto out; + } +#endif + /* peek_buf[] is an int array, not char. Can contain EOF. */ + ch = i->peek_buf[0]; + if (ch != 0) { + int ch2 = i->peek_buf[1]; + i->peek_buf[0] = ch2; + if (ch2 == 0) /* very likely, avoid redundant write */ + goto out; + i->peek_buf[1] = 0; + goto out; + } + + ch = fgetc_interactive(i); + out: + debug_printf("file_get: got '%c' %d\n", ch, ch); + i->last_char = ch; +#if ENABLE_HUSH_LINENO_VAR + if (ch == '\n') { + G.parse_lineno++; + debug_printf_parse("G.parse_lineno++ = %u\n", G.parse_lineno); + } +#endif + return ch; +} + +static int i_peek(struct in_str *i) +{ + int ch; + + if (!i->file) { + /* string-based in_str */ + /* Doesn't report EOF on NUL. None of the callers care. */ + return (unsigned char)*i->p; + } + + /* FILE-based in_str */ + +#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE + /* This can be stdin, check line editing char[] buffer */ + if (i->p && *i->p != '\0') + return (unsigned char)*i->p; +#endif + /* peek_buf[] is an int array, not char. Can contain EOF. */ + ch = i->peek_buf[0]; + if (ch != 0) + return ch; + + /* Need to get a new char */ + ch = fgetc_interactive(i); + debug_printf("file_peek: got '%c' %d\n", ch, ch); + + /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */ +#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE + if (i->p) { + i->p -= 1; + return ch; + } +#endif + i->peek_buf[0] = ch; + /*i->peek_buf[1] = 0; - already is */ + return ch; +} + +/* Only ever called if i_peek() was called, and did not return EOF. + * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL, + * not end-of-line. Therefore we never need to read a new editing line here. + */ +static int i_peek2(struct in_str *i) +{ + int ch; + + /* There are two cases when i->p[] buffer exists. + * (1) it's a string in_str. + * (2) It's a file, and we have a saved line editing buffer. + * In both cases, we know that i->p[0] exists and not NUL, and + * the peek2 result is in i->p[1]. + */ + if (i->p) + return (unsigned char)i->p[1]; + + /* Now we know it is a file-based in_str. */ + + /* peek_buf[] is an int array, not char. Can contain EOF. */ + /* Is there 2nd char? */ + ch = i->peek_buf[1]; + if (ch == 0) { + /* We did not read it yet, get it now */ + do ch = hfgetc(i->file); while (ch == '\0'); + i->peek_buf[1] = ch; + } + + debug_printf("file_peek2: got '%c' %d\n", ch, ch); + return ch; +} + +static int i_getch_and_eat_bkslash_nl(struct in_str *input) +{ + for (;;) { + int ch, ch2; + + ch = i_getch(input); + if (ch != '\') + return ch; + ch2 = i_peek(input); + if (ch2 != '\n') + return ch; + /* backslash+newline, skip it */ + i_getch(input); + } +} + +/* Note: this function _eats_ <newline> pairs, safe to use plain + * i_getch() after it instead of i_getch_and_eat_bkslash_nl(). + */ +static int i_peek_and_eat_bkslash_nl(struct in_str *input) +{ + for (;;) { + int ch, ch2; + + ch = i_peek(input); + if (ch != '\') + return ch; + ch2 = i_peek2(input); + if (ch2 != '\n') + return ch; + /* backslash+newline, skip it */ + i_getch(input); + i_getch(input); + } +} + +static void setup_file_in_str(struct in_str *i, HFILE *fp) +{ + memset(i, 0, sizeof(*i)); + i->file = fp; + /* i->p = NULL; */ +} + +static void setup_string_in_str(struct in_str *i, const char *s) +{ + memset(i, 0, sizeof(*i)); + /*i->file = NULL */; + i->p = s; +} + + +/* + * o_string support + */ +#define B_CHUNK (32 * sizeof(char*)) + +static void o_reset_to_empty_unquoted(o_string *o) +{ + o->length = 0; + o->has_quoted_part = 0; + if (o->data) + o->data[0] = '\0'; +} + +static void o_free_and_set_NULL(o_string *o) +{ + free(o->data); + memset(o, 0, sizeof(*o)); +} + +static ALWAYS_INLINE void o_free(o_string *o) +{ + free(o->data); +} + +static void o_grow_by(o_string *o, int len) +{ + if (o->length + len > o->maxlen) { + o->maxlen += (2 * len) | (B_CHUNK-1); + o->data = xrealloc(o->data, 1 + o->maxlen); + } +} + +static void o_addchr(o_string *o, int ch) +{ + debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o); + if (o->length < o->maxlen) { + /* likely. avoid o_grow_by() call */ + add: + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; + return; + } + o_grow_by(o, 1); + goto add; +} + +#if 0 +/* Valid only if we know o_string is not empty */ +static void o_delchr(o_string *o) +{ + o->length--; + o->data[o->length] = '\0'; +} +#endif + +static void o_addblock(o_string *o, const char *str, int len) +{ + o_grow_by(o, len); + ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0'; + o->length += len; +} + +static void o_addstr(o_string *o, const char *str) +{ + o_addblock(o, str, strlen(str)); +} + +static void o_addstr_with_NUL(o_string *o, const char *str) +{ + o_addblock(o, str, strlen(str) + 1); +} + +#if !BB_MMU +static void nommu_addchr(o_string *o, int ch) +{ + if (o) + o_addchr(o, ch); +} +#else +# define nommu_addchr(o, str) ((void)0) +#endif + +#if ENABLE_HUSH_MODE_X +static void x_mode_addchr(int ch) +{ + o_addchr(&G.x_mode_buf, ch); +} +static void x_mode_addstr(const char *str) +{ + o_addstr(&G.x_mode_buf, str); +} +static void x_mode_addblock(const char *str, int len) +{ + o_addblock(&G.x_mode_buf, str, len); +} +static void x_mode_prefix(void) +{ + int n = G.x_mode_depth; + do x_mode_addchr('+'); while (--n >= 0); +} +static void x_mode_flush(void) +{ + int len = G.x_mode_buf.length; + if (len <= 0) + return; + if (G.x_mode_fd > 0) { + G.x_mode_buf.data[len] = '\n'; + full_write(G.x_mode_fd, G.x_mode_buf.data, len + 1); + } + G.x_mode_buf.length = 0; +} +#endif + +/* + * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side. + * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v. + * Apparently, on unquoted $v bash still does globbing + * ("v='*.txt'; echo $v" prints all .txt files), + * but NOT brace expansion! Thus, there should be TWO independent + * quoting mechanisms on $v expansion side: one protects + * $v from brace expansion, and other additionally protects "$v" against globbing. + * We have only second one. + */ + +#if ENABLE_HUSH_BRACE_EXPANSION +# define MAYBE_BRACES "{}" +#else +# define MAYBE_BRACES "" +#endif + +/* My analysis of quoting semantics tells me that state information + * is associated with a destination, not a source. + */ +static void o_addqchr(o_string *o, int ch) +{ + int sz = 1; + /* '-' is included because of this case: + * >filename0 >filename1 >filename9; v='-'; echo filename[0"$v"9] + */ + char *found = strchr("*?[-\" MAYBE_BRACES, ch); + if (found) + sz++; + o_grow_by(o, sz); + if (found) { + o->data[o->length] = '\'; + o->length++; + } + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addQchr(o_string *o, int ch) +{ + int sz = 1; + if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS) + && strchr("*?[-\" MAYBE_BRACES, ch) + ) { + sz++; + o->data[o->length] = '\'; + o->length++; + } + o_grow_by(o, sz); + o->data[o->length] = ch; + o->length++; + o->data[o->length] = '\0'; +} + +static void o_addqblock(o_string *o, const char *str, int len) +{ + while (len) { + char ch; + int sz; + int ordinary_cnt = strcspn(str, "*?[-\" MAYBE_BRACES); + if (ordinary_cnt > len) /* paranoia */ + ordinary_cnt = len; + o_addblock(o, str, ordinary_cnt); + if (ordinary_cnt == len) + return; /* NUL is already added by o_addblock */ + str += ordinary_cnt; + len -= ordinary_cnt + 1; /* we are processing + 1 char below */ + + ch = *str++; + sz = 1; + if (ch) { /* it is necessarily one of "*?[-\" MAYBE_BRACES */ + sz++; + o->data[o->length] = '\'; + o->length++; + } + o_grow_by(o, sz); + o->data[o->length] = ch; + o->length++; + } + o->data[o->length] = '\0'; +} + +static void o_addQblock(o_string *o, const char *str, int len) +{ + if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) { + o_addblock(o, str, len); + return; + } + o_addqblock(o, str, len); +} + +static void o_addQstr(o_string *o, const char *str) +{ + o_addQblock(o, str, strlen(str)); +} + +/* A special kind of o_string for $VAR and `cmd` expansion. + * It contains char* list[] at the beginning, which is grown in 16 element + * increments. Actual string data starts at the next multiple of 16 * (char*). + * list[i] contains an INDEX (int!) into this string data. + * It means that if list[] needs to grow, data needs to be moved higher up + * but list[i]'s need not be modified. + * NB: remembering how many list[i]'s you have there is crucial. + * o_finalize_list() operation post-processes this structure - calculates + * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well. + */ +#if DEBUG_EXPAND || DEBUG_GLOB +static void debug_print_list(const char *prefix, o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + int i = 0; + + indent(); + fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n", + prefix, list, n, string_start, o->length, o->maxlen, + !!(o->o_expflags & EXP_FLAG_GLOB), + o->has_quoted_part, + !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)); + while (i < n) { + indent(); + fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i], + o->data + (int)(uintptr_t)list[i] + string_start, + o->data + (int)(uintptr_t)list[i] + string_start); + i++; + } + if (n) { + const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start; + indent(); + fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data)); + } +} +#else +# define debug_print_list(prefix, o, n) ((void)0) +#endif + +/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value + * in list[n] so that it points past last stored byte so far. + * It returns n+1. */ +static int o_save_ptr_helper(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start; + int string_len; + + if (!o->has_empty_slot) { + string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + string_len = o->length - string_start; + if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */ + debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start); + /* list[n] points to string_start, make space for 16 more pointers */ + o->maxlen += 0x10 * sizeof(list[0]); + o->data = xrealloc(o->data, o->maxlen + 1); + list = (char**)o->data; + memmove(list + n + 0x10, list + n, string_len); + /* + * expand_on_ifs() has a "previous argv[] ends in IFS?" + * check. (grep for -prev-ifs-check-). + * Ensure that argv[-1][last] is not garbage + * but zero bytes, to save index check there. + */ + list[n + 0x10 - 1] = 0; + o->length += 0x10 * sizeof(list[0]); + } else { + debug_printf_list("list[%d]=%d string_start=%d\n", + n, string_len, string_start); + } + } else { + /* We have empty slot at list[n], reuse without growth */ + string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */ + string_len = o->length - string_start; + debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", + n, string_len, string_start); + o->has_empty_slot = 0; + } + o->has_quoted_part = 0; + list[n] = (char*)(uintptr_t)string_len; + return n + 1; +} + +/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */ +static int o_get_last_ptr(o_string *o, int n) +{ + char **list = (char**)o->data; + int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + + return ((int)(uintptr_t)list[n-1]) + string_start; +} + +/* + * Globbing routines. + * + * Most words in commands need to be globbed, even ones which are + * (single or double) quoted. This stems from the possiblity of + * constructs like "abc"* and 'abc'* - these should be globbed. + * Having a different code path for fully-quoted strings ("abc", + * 'abc') would only help performance-wise, but we still need + * code for partially-quoted strings. + * + * Unfortunately, if we want to match bash and ash behavior in all cases, + * the logic can't be "shell-syntax argument is first transformed + * to a string, then globbed, and if globbing does not match anything, + * it is used verbatim". Here are two examples where it fails: + * + * echo 'b*'? + * + * The globbing can't be avoided (because of '?' at the end). + * The glob pattern is: b\*? - IOW, both \ and * are literals + * and are glob-escaped. If this does not match, bash/ash print b*? + * - IOW: they "unbackslash" the glob pattern. + * Now, look at this: + * + * v='\*'; echo b$v? + * + * The glob pattern is the same here: b\*? - the unquoted $v expansion + * should be used as glob pattern with no changes. However, if glob + * does not match, bash/ash print b\*? - NOT THE SAME as first example! + * + * ash implements this by having an encoded representation of the word + * to glob, which IS NOT THE SAME as the glob pattern - it has more data. + * Glob pattern is derived from it. If glob fails, the decision what result + * should be is made using that encoded representation. Not glob pattern. + */ + +#if ENABLE_HUSH_BRACE_EXPANSION +/* There in a GNU extension, GLOB_BRACE, but it is not usable: + * first, it processes even {a} (no commas), second, + * I didn't manage to make it return strings when they don't match + * existing files. Need to re-implement it. + */ + +/* Helper */ +static int glob_needed(const char *s) +{ + while (*s) { + if (*s == '\') { + if (!s[1]) + return 0; + s += 2; + continue; + } + if (*s == '*' || *s == '[' || *s == '?' || *s == '{') + return 1; + s++; + } + return 0; +} +/* Return pointer to next closing brace or to comma */ +static const char *next_brace_sub(const char *cp) +{ + unsigned depth = 0; + cp++; + while (*cp != '\0') { + if (*cp == '\') { + if (*++cp == '\0') + break; + cp++; + continue; + } + if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0)) + break; + if (*cp++ == '{') + depth++; + } + + return *cp != '\0' ? cp : NULL; +} +/* Recursive brace globber. Note: may garble pattern[]. */ +static int glob_brace(char *pattern, o_string *o, int n) +{ + char *new_pattern_buf; + const char *begin; + const char *next; + const char *rest; + const char *p; + size_t rest_len; + + debug_printf_glob("glob_brace('%s')\n", pattern); + + begin = pattern; + while (1) { + if (*begin == '\0') + goto simple_glob; + if (*begin == '{') { + /* Find the first sub-pattern and at the same time + * find the rest after the closing brace */ + next = next_brace_sub(begin); + if (next == NULL) { + /* An illegal expression */ + goto simple_glob; + } + if (*next == '}') { + /* "{abc}" with no commas - illegal + * brace expr, disregard and skip it */ + begin = next + 1; + continue; + } + break; + } + if (*begin == '\' && begin[1] != '\0') + begin++; + begin++; + } + debug_printf_glob("begin:%s\n", begin); + debug_printf_glob("next:%s\n", next); + + /* Now find the end of the whole brace expression */ + rest = next; + while (*rest != '}') { + rest = next_brace_sub(rest); + if (rest == NULL) { + /* An illegal expression */ + goto simple_glob; + } + debug_printf_glob("rest:%s\n", rest); + } + rest_len = strlen(++rest) + 1; + + /* We are sure the brace expression is well-formed */ + + /* Allocate working buffer large enough for our work */ + new_pattern_buf = xmalloc(strlen(pattern)); + + /* We have a brace expression. BEGIN points to the opening {, + * NEXT points past the terminator of the first element, and REST + * points past the final }. We will accumulate result names from + * recursive runs for each brace alternative in the buffer using + * GLOB_APPEND. */ + + p = begin + 1; + while (1) { + /* Construct the new glob expression */ + memcpy( + mempcpy( + mempcpy(new_pattern_buf, + /* We know the prefix for all sub-patterns */ + pattern, begin - pattern), + p, next - p), + rest, rest_len); + + /* Note: glob_brace() may garble new_pattern_buf[]. + * That's why we re-copy prefix every time (1st memcpy above). + */ + n = glob_brace(new_pattern_buf, o, n); + if (*next == '}') { + /* We saw the last entry */ + break; + } + p = next + 1; + next = next_brace_sub(next); + } + free(new_pattern_buf); + return n; + + simple_glob: + { + int gr; + glob_t globdata; + + memset(&globdata, 0, sizeof(globdata)); + gr = glob(pattern, 0, NULL, &globdata); + debug_printf_glob("glob('%s'):%d\n", pattern, gr); + if (gr != 0) { + if (gr == GLOB_NOMATCH) { + globfree(&globdata); + /* NB: garbles parameter */ + unbackslash(pattern); + o_addstr_with_NUL(o, pattern); + debug_printf_glob("glob pattern '%s' is literal\n", pattern); + return o_save_ptr_helper(o, n); + } + if (gr == GLOB_NOSPACE) + bb_die_memory_exhausted(); + /* GLOB_ABORTED? Only happens with GLOB_ERR flag, + * but we didn't specify it. Paranoia again. */ + bb_error_msg_and_die("glob error %d on '%s'", gr, pattern); + } + if (globdata.gl_pathv && globdata.gl_pathv[0]) { + char **argv = globdata.gl_pathv; + while (1) { + o_addstr_with_NUL(o, *argv); + n = o_save_ptr_helper(o, n); + argv++; + if (!*argv) + break; + } + } + globfree(&globdata); + } + return n; +} +/* Performs globbing on last list[], + * saving each result as a new list[]. + */ +static int perform_glob(o_string *o, int n) +{ + char *pattern, *copy; + + debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data); + if (!o->data) + return o_save_ptr_helper(o, n); + pattern = o->data + o_get_last_ptr(o, n); + debug_printf_glob("glob pattern '%s'\n", pattern); + if (!glob_needed(pattern)) { + /* unbackslash last string in o in place, fix length */ + o->length = unbackslash(pattern) - o->data; + debug_printf_glob("glob pattern '%s' is literal\n", pattern); + return o_save_ptr_helper(o, n); + } + + copy = xstrdup(pattern); + /* "forget" pattern in o */ + o->length = pattern - o->data; + n = glob_brace(copy, o, n); + free(copy); + if (DEBUG_GLOB) + debug_print_list("perform_glob returning", o, n); + return n; +} + +#else /* !HUSH_BRACE_EXPANSION */ + +/* Helper */ +static int glob_needed(const char *s) +{ + while (*s) { + if (*s == '\') { + if (!s[1]) + return 0; + s += 2; + continue; + } + if (*s == '*' || *s == '[' || *s == '?') + return 1; + s++; + } + return 0; +} +/* Performs globbing on last list[], + * saving each result as a new list[]. + */ +static int perform_glob(o_string *o, int n) +{ + glob_t globdata; + int gr; + char *pattern; + + debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data); + if (!o->data) + return o_save_ptr_helper(o, n); + pattern = o->data + o_get_last_ptr(o, n); + debug_printf_glob("glob pattern '%s'\n", pattern); + if (!glob_needed(pattern)) { + literal: + /* unbackslash last string in o in place, fix length */ + o->length = unbackslash(pattern) - o->data; + debug_printf_glob("glob pattern '%s' is literal\n", pattern); + return o_save_ptr_helper(o, n); + } + + memset(&globdata, 0, sizeof(globdata)); + /* Can't use GLOB_NOCHECK: it does not unescape the string. + * If we glob "*.*" and don't find anything, we need + * to fall back to using literal "*.*", but GLOB_NOCHECK + * will return "*.*"! + */ + gr = glob(pattern, 0, NULL, &globdata); + debug_printf_glob("glob('%s'):%d\n", pattern, gr); + if (gr != 0) { + if (gr == GLOB_NOMATCH) { + globfree(&globdata); + goto literal; + } + if (gr == GLOB_NOSPACE) + bb_die_memory_exhausted(); + /* GLOB_ABORTED? Only happens with GLOB_ERR flag, + * but we didn't specify it. Paranoia again. */ + bb_error_msg_and_die("glob error %d on '%s'", gr, pattern); + } + if (globdata.gl_pathv && globdata.gl_pathv[0]) { + char **argv = globdata.gl_pathv; + /* "forget" pattern in o */ + o->length = pattern - o->data; + while (1) { + o_addstr_with_NUL(o, *argv); + n = o_save_ptr_helper(o, n); + argv++; + if (!*argv) + break; + } + } + globfree(&globdata); + if (DEBUG_GLOB) + debug_print_list("perform_glob returning", o, n); + return n; +} + +#endif /* !HUSH_BRACE_EXPANSION */ + +/* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered. + * Otherwise, just finish current list[] and start new */ +static int o_save_ptr(o_string *o, int n) +{ + if (o->o_expflags & EXP_FLAG_GLOB) { + /* If o->has_empty_slot, list[n] was already globbed + * (if it was requested back then when it was filled) + * so don't do that again! */ + if (!o->has_empty_slot) + return perform_glob(o, n); /* o_save_ptr_helper is inside */ + } + return o_save_ptr_helper(o, n); +} + +/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */ +static char **o_finalize_list(o_string *o, int n) +{ + char **list; + int string_start; + + if (DEBUG_EXPAND) + debug_print_list("finalized", o, n); + debug_printf_expand("finalized n:%d\n", n); + list = (char**)o->data; + string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]); + list[--n] = NULL; + while (n) { + n--; + list[n] = o->data + (int)(uintptr_t)list[n] + string_start; + } + return list; +} + +static void free_pipe_list(struct pipe *pi); + +/* Returns pi->next - next pipe in the list */ +static struct pipe *free_pipe(struct pipe *pi) +{ + struct pipe *next; + int i; + + debug_printf_clean("free_pipe (pid %d)\n", getpid()); + for (i = 0; i < pi->num_cmds; i++) { + struct command *command; + struct redir_struct *r, *rnext; + + command = &pi->cmds[i]; + debug_printf_clean(" command %d:\n", i); + if (command->argv) { + if (DEBUG_CLEAN) { + int a; + char **p; + for (a = 0, p = command->argv; *p; a++, p++) { + debug_printf_clean(" argv[%d] = %s\n", a, *p); + } + } + free_strings(command->argv); + //command->argv = NULL; + } + /* not "else if": on syntax error, we may have both! */ + if (command->group) { + debug_printf_clean(" begin group (cmd_type:%d)\n", + command->cmd_type); + free_pipe_list(command->group); + debug_printf_clean(" end group\n"); + //command->group = NULL; + } + /* else is crucial here. + * If group != NULL, child_func is meaningless */ +#if ENABLE_HUSH_FUNCTIONS + else if (command->child_func) { + debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func); + command->child_func->parent_cmd = NULL; + } +#endif +#if !BB_MMU + free(command->group_as_string); + //command->group_as_string = NULL; +#endif + for (r = command->redirects; r; r = rnext) { + debug_printf_clean(" redirect %d%s", + r->rd_fd, redir_table[r->rd_type].descrip); + /* guard against the case >$FOO, where foo is unset or blank */ + if (r->rd_filename) { + debug_printf_clean(" fname:'%s'\n", r->rd_filename); + free(r->rd_filename); + //r->rd_filename = NULL; + } + debug_printf_clean(" rd_dup:%d\n", r->rd_dup); + rnext = r->next; + free(r); + } + //command->redirects = NULL; + } + free(pi->cmds); /* children are an array, they get freed all at once */ + //pi->cmds = NULL; +#if ENABLE_HUSH_JOB + free(pi->cmdtext); + //pi->cmdtext = NULL; +#endif + + next = pi->next; + free(pi); + return next; +} + +static void free_pipe_list(struct pipe *pi) +{ + while (pi) { +#if HAS_KEYWORDS + debug_printf_clean("pipe reserved word %d\n", pi->res_word); +#endif + debug_printf_clean("pipe followup code %d\n", pi->followup); + pi = free_pipe(pi); + } +} + + +/*** Parsing routines ***/ + +#ifndef debug_print_tree +static void debug_print_tree(struct pipe *pi, int lvl) +{ + static const char *const PIPE[] = { + [PIPE_SEQ] = "SEQ", + [PIPE_AND] = "AND", + [PIPE_OR ] = "OR" , + [PIPE_BG ] = "BG" , + }; + static const char *RES[] = { + [RES_NONE ] = "NONE" , +# if ENABLE_HUSH_IF + [RES_IF ] = "IF" , + [RES_THEN ] = "THEN" , + [RES_ELIF ] = "ELIF" , + [RES_ELSE ] = "ELSE" , + [RES_FI ] = "FI" , +# endif +# if ENABLE_HUSH_LOOPS + [RES_FOR ] = "FOR" , + [RES_WHILE] = "WHILE", + [RES_UNTIL] = "UNTIL", + [RES_DO ] = "DO" , + [RES_DONE ] = "DONE" , +# endif +# if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE + [RES_IN ] = "IN" , +# endif +# if ENABLE_HUSH_CASE + [RES_CASE ] = "CASE" , + [RES_CASE_IN ] = "CASE_IN" , + [RES_MATCH] = "MATCH", + [RES_CASE_BODY] = "CASE_BODY", + [RES_ESAC ] = "ESAC" , +# endif + [RES_XXXX ] = "XXXX" , + [RES_SNTX ] = "SNTX" , + }; + static const char *const CMDTYPE[] = { + "{}", + "()", + "[noglob]", +# if ENABLE_HUSH_FUNCTIONS + "func()", +# endif + }; + + int pin, prn; + + pin = 0; + while (pi) { + fdprintf(2, "%*spipe %d #cmds:%d %sres_word=%s followup=%d %s\n", + lvl*2, "", + pin, + pi->num_cmds, + (IF_HAS_KEYWORDS(pi->pi_inverted ? "! " :) ""), + RES[pi->res_word], + pi->followup, PIPE[pi->followup] + ); + prn = 0; + while (prn < pi->num_cmds) { + struct command *command = &pi->cmds[prn]; + char **argv = command->argv; + + fdprintf(2, "%*s cmd %d assignment_cnt:%d", + lvl*2, "", prn, + command->assignment_cnt); +# if ENABLE_HUSH_LINENO_VAR + fdprintf(2, " LINENO:%u", command->lineno); +# endif + if (command->group) { + fdprintf(2, " group %s: (argv=%p)%s%s\n", + CMDTYPE[command->cmd_type], + argv +# if !BB_MMU + , " group_as_string:", command->group_as_string +# else + , "", "" +# endif + ); + debug_print_tree(command->group, lvl+1); + prn++; + continue; + } + if (argv) while (*argv) { + fdprintf(2, " '%s'", *argv); + argv++; + } + if (command->redirects) + fdprintf(2, " {redir}"); + fdprintf(2, "\n"); + prn++; + } + pi = pi->next; + pin++; + } +} +#endif /* debug_print_tree */ + +static struct pipe *new_pipe(void) +{ + struct pipe *pi; + pi = xzalloc(sizeof(struct pipe)); + /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */ + return pi; +} + +/* Command (member of a pipe) is complete, or we start a new pipe + * if ctx->command is NULL. + * No errors possible here. + */ +static int done_command(struct parse_context *ctx) +{ + /* The command is really already in the pipe structure, so + * advance the pipe counter and make a new, null command. */ + struct pipe *pi = ctx->pipe; + struct command *command = ctx->command; + +#if 0 /* Instead we emit error message at run time */ + if (ctx->pending_redirect) { + /* For example, "cmd >" (no filename to redirect to) */ + syntax_error("invalid redirect"); + ctx->pending_redirect = NULL; + } +#endif + + if (command) { + if (IS_NULL_CMD(command)) { + debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds); + goto clear_and_ret; + } + pi->num_cmds++; + debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds); + //debug_print_tree(ctx->list_head, 20); + } else { + debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds); + } + + /* Only real trickiness here is that the uncommitted + * command structure is not counted in pi->num_cmds. */ + pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1)); + ctx->command = command = &pi->cmds[pi->num_cmds]; + clear_and_ret: + memset(command, 0, sizeof(*command)); +#if ENABLE_HUSH_LINENO_VAR + command->lineno = G.parse_lineno; + debug_printf_parse("command->lineno = G.parse_lineno (%u)\n", G.parse_lineno); +#endif + return pi->num_cmds; /* used only for 0/nonzero check */ +} + +static void done_pipe(struct parse_context *ctx, pipe_style type) +{ + int not_null; + + debug_printf_parse("done_pipe entered, followup %d\n", type); + /* Close previous command */ + not_null = done_command(ctx); +#if HAS_KEYWORDS + ctx->pipe->pi_inverted = ctx->ctx_inverted; + ctx->ctx_inverted = 0; + ctx->pipe->res_word = ctx->ctx_res_w; +#endif + if (type == PIPE_BG && ctx->list_head != ctx->pipe) { + /* Necessary since && and || have precedence over &: + * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2, + * in a backgrounded subshell. + */ + struct pipe *pi; + struct command *command; + + /* Is this actually this construct, all pipes end with && or ||? */ + pi = ctx->list_head; + while (pi != ctx->pipe) { + if (pi->followup != PIPE_AND && pi->followup != PIPE_OR) + goto no_conv; + pi = pi->next; + } + + debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n"); + pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */ + pi = xzalloc(sizeof(*pi)); + pi->followup = PIPE_BG; + pi->num_cmds = 1; + pi->cmds = xzalloc(sizeof(pi->cmds[0])); + command = &pi->cmds[0]; + if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */ + command->cmd_type = CMD_NORMAL; + command->group = ctx->list_head; +#if !BB_MMU + command->group_as_string = xstrndup( + ctx->as_string.data, + ctx->as_string.length - 1 /* do not copy last char, "&" */ + ); +#endif + /* Replace all pipes in ctx with one newly created */ + ctx->list_head = ctx->pipe = pi; + /* for cases like "cmd && &", do not be tricked by last command + * being null - the entire {...} & is NOT null! */ + not_null = 1; + } else { + no_conv: + ctx->pipe->followup = type; + } + + /* Without this check, even just <enter> on command line generates + * tree of three NOPs (!). Which is harmless but annoying. + * IOW: it is safe to do it unconditionally. */ + if (not_null +#if ENABLE_HUSH_IF + || ctx->ctx_res_w == RES_FI +#endif +#if ENABLE_HUSH_LOOPS + || ctx->ctx_res_w == RES_DONE + || ctx->ctx_res_w == RES_FOR + || ctx->ctx_res_w == RES_IN +#endif +#if ENABLE_HUSH_CASE + || ctx->ctx_res_w == RES_ESAC +#endif + ) { + struct pipe *new_p; + debug_printf_parse("done_pipe: adding new pipe: " + "not_null:%d ctx->ctx_res_w:%d\n", + not_null, ctx->ctx_res_w); + new_p = new_pipe(); + ctx->pipe->next = new_p; + ctx->pipe = new_p; + /* RES_THEN, RES_DO etc are "sticky" - + * they remain set for pipes inside if/while. + * This is used to control execution. + * RES_FOR and RES_IN are NOT sticky (needed to support + * cases where variable or value happens to match a keyword): + */ +#if ENABLE_HUSH_LOOPS + if (ctx->ctx_res_w == RES_FOR + || ctx->ctx_res_w == RES_IN) + ctx->ctx_res_w = RES_NONE; +#endif +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + ctx->ctx_res_w = RES_CASE_BODY; + if (ctx->ctx_res_w == RES_CASE) + ctx->ctx_res_w = RES_CASE_IN; +#endif + ctx->command = NULL; /* trick done_command below */ + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; + */ + done_command(ctx); + //debug_print_tree(ctx->list_head, 10); + } + debug_printf_parse("done_pipe return\n"); +} + +static void initialize_context(struct parse_context *ctx) +{ + memset(ctx, 0, sizeof(*ctx)); + if (MAYBE_ASSIGNMENT != 0) + ctx->is_assignment = MAYBE_ASSIGNMENT; + ctx->pipe = ctx->list_head = new_pipe(); + /* Create the memory for command, roughly: + * ctx->pipe->cmds = new struct command; + * ctx->command = &ctx->pipe->cmds[0]; + */ + done_command(ctx); +} + +/* If a reserved word is found and processed, parse context is modified + * and 1 is returned. + */ +#if HAS_KEYWORDS +struct reserved_combo { + char literal[6]; + unsigned char res; + unsigned char assignment_flag; + uint32_t flag; +}; +enum { + FLAG_END = (1 << RES_NONE ), +# if ENABLE_HUSH_IF + FLAG_IF = (1 << RES_IF ), + FLAG_THEN = (1 << RES_THEN ), + FLAG_ELIF = (1 << RES_ELIF ), + FLAG_ELSE = (1 << RES_ELSE ), + FLAG_FI = (1 << RES_FI ), +# endif +# if ENABLE_HUSH_LOOPS + FLAG_FOR = (1 << RES_FOR ), + FLAG_WHILE = (1 << RES_WHILE), + FLAG_UNTIL = (1 << RES_UNTIL), + FLAG_DO = (1 << RES_DO ), + FLAG_DONE = (1 << RES_DONE ), + FLAG_IN = (1 << RES_IN ), +# endif +# if ENABLE_HUSH_CASE + FLAG_MATCH = (1 << RES_MATCH), + FLAG_ESAC = (1 << RES_ESAC ), +# endif + FLAG_START = (1 << RES_XXXX ), +}; + +static const struct reserved_combo* match_reserved_word(o_string *word) +{ + /* Mostly a list of accepted follow-up reserved words. + * FLAG_END means we are done with the sequence, and are ready + * to turn the compound list into a command. + * FLAG_START means the word must start a new compound list. + */ + static const struct reserved_combo reserved_list[] ALIGN4 = { +# if ENABLE_HUSH_IF + { "!", RES_NONE, NOT_ASSIGNMENT , 0 }, + { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START }, + { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, + { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN }, + { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI }, + { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END }, +# endif +# if ENABLE_HUSH_LOOPS + { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START }, + { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START }, + { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START }, + { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO }, + { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE }, + { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END }, +# endif +# if ENABLE_HUSH_CASE + { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START }, + { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END }, +# endif + }; + const struct reserved_combo *r; + + for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { + if (strcmp(word->data, r->literal) == 0) + return r; + } + return NULL; +} +/* Return NULL: not a keyword, else: keyword + */ +static const struct reserved_combo* reserved_word(struct parse_context *ctx) +{ +# if ENABLE_HUSH_CASE + static const struct reserved_combo reserved_match = { + "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC + }; +# endif + const struct reserved_combo *r; + + if (ctx->word.has_quoted_part) + return 0; + r = match_reserved_word(&ctx->word); + if (!r) + return r; /* NULL */ + + debug_printf("found reserved word %s, res %d\n", r->literal, r->res); +# if ENABLE_HUSH_CASE + if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) { + /* "case word IN ..." - IN part starts first MATCH part */ + r = &reserved_match; + } else +# endif + if (r->flag == 0) { /* '!' */ + if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */ + syntax_error("! ! command"); + ctx->ctx_res_w = RES_SNTX; + } + ctx->ctx_inverted = 1; + return r; + } + if (r->flag & FLAG_START) { + struct parse_context *old; + + old = xmemdup(ctx, sizeof(*ctx)); + debug_printf_parse("push stack %p\n", old); + initialize_context(ctx); + ctx->stack = old; + } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) { + syntax_error_at(ctx->word.data); + ctx->ctx_res_w = RES_SNTX; + return r; + } else { + /* "{...} fi" is ok. "{...} if" is not + * Example: + * if { echo foo; } then { echo bar; } fi */ + if (ctx->command->group) + done_pipe(ctx, PIPE_SEQ); + } + + ctx->ctx_res_w = r->res; + ctx->old_flag = r->flag; + ctx->is_assignment = r->assignment_flag; + debug_printf_parse("ctx->is_assignment='%s'\n", assignment_flag[ctx->is_assignment]); + + if (ctx->old_flag & FLAG_END) { + struct parse_context *old; + + done_pipe(ctx, PIPE_SEQ); + debug_printf_parse("pop stack %p\n", ctx->stack); + old = ctx->stack; + old->command->group = ctx->list_head; + old->command->cmd_type = CMD_NORMAL; +# if !BB_MMU + /* At this point, the compound command's string is in + * ctx->as_string... except for the leading keyword! + * Consider this example: "echo a | if true; then echo a; fi" + * ctx->as_string will contain "true; then echo a; fi", + * with "if " remaining in old->as_string! + */ + { + char *str; + int len = old->as_string.length; + /* Concatenate halves */ + o_addstr(&old->as_string, ctx->as_string.data); + o_free(&ctx->as_string); + /* Find where leading keyword starts in first half */ + str = old->as_string.data + len; + if (str > old->as_string.data) + str--; /* skip whitespace after keyword */ + while (str > old->as_string.data && isalpha(str[-1])) + str--; + /* Ugh, we're done with this horrid hack */ + old->command->group_as_string = xstrdup(str); + debug_printf_parse("pop, remembering as:'%s'\n", + old->command->group_as_string); + } +# endif + *ctx = *old; /* physical copy */ + free(old); + } + return r; +} +#endif /* HAS_KEYWORDS */ + +/* Word is complete, look at it and update parsing context. + * Normal return is 0. Syntax errors return 1. + * Note: on return, word is reset, but not o_free'd! + */ +static int done_word(struct parse_context *ctx) +{ + struct command *command = ctx->command; + + debug_printf_parse("done_word entered: '%s' %p\n", ctx->word.data, command); + if (ctx->word.length == 0 && !ctx->word.has_quoted_part) { + debug_printf_parse("done_word return 0: true null, ignored\n"); + return 0; + } + + if (ctx->pending_redirect) { + /* We do not glob in e.g. >*.tmp case. bash seems to glob here + * only if run as "bash", not "sh" */ + /* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html + * "2.7 Redirection + * If the redirection operator is "<<" or "<<-", the word + * that follows the redirection operator shall be + * subjected to quote removal; it is unspecified whether + * any of the other expansions occur. For the other + * redirection operators, the word that follows the + * redirection operator shall be subjected to tilde + * expansion, parameter expansion, command substitution, + * arithmetic expansion, and quote removal. + * Pathname expansion shall not be performed + * on the word by a non-interactive shell; an interactive + * shell may perform it, but shall do so only when + * the expansion would result in one word." + */ +//bash does not do parameter/command substitution or arithmetic expansion +//for _heredoc_ redirection word: these constructs look for exact eof marker +// as written: +// <<EOF$t +// <<EOF$((1)) +// <<EOF`true` [this case also makes heredoc "quoted", a-la <<"EOF". Probably bash-4.3.43 bug] + + ctx->pending_redirect->rd_filename = xstrdup(ctx->word.data); + /* Cater for >\file case: + * >\a creates file a; >\a, >"\a", >"\a" create file \a + * Same with heredocs: + * for <<\H delim is H; <<\H, <<"\H", <<"\H" - \H + */ + if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) { + unbackslash(ctx->pending_redirect->rd_filename); + /* Is it <<"HEREDOC"? */ + if (ctx->word.has_quoted_part) { + ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED; + } + } + debug_printf_parse("word stored in rd_filename: '%s'\n", ctx->word.data); + ctx->pending_redirect = NULL; + } else { +#if HAS_KEYWORDS +# if ENABLE_HUSH_CASE + if (ctx->ctx_dsemicolon + && strcmp(ctx->word.data, "esac") != 0 /* not "... pattern) cmd;; esac" */ + ) { + /* already done when ctx_dsemicolon was set to 1: */ + /* ctx->ctx_res_w = RES_MATCH; */ + ctx->ctx_dsemicolon = 0; + } else +# endif +# if defined(CMD_TEST2_SINGLEWORD_NOGLOB) + if (command->cmd_type == CMD_TEST2_SINGLEWORD_NOGLOB + && strcmp(ctx->word.data, "]]") == 0 + ) { + /* allow "[[ ]] >file" etc */ + command->cmd_type = CMD_SINGLEWORD_NOGLOB; + } else +# endif + if (!command->argv /* if it's the first word... */ +# if ENABLE_HUSH_LOOPS + && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */ + && ctx->ctx_res_w != RES_IN +# endif +# if ENABLE_HUSH_CASE + && ctx->ctx_res_w != RES_CASE +# endif + ) { + const struct reserved_combo *reserved; + reserved = reserved_word(ctx); + debug_printf_parse("checking for reserved-ness: %d\n", !!reserved); + if (reserved) { +# if ENABLE_HUSH_LINENO_VAR +/* Case: + * "while ...; do + * cmd ..." + * If we don't close the pipe _now_, immediately after "do", lineno logic + * sees "cmd" as starting at "do" - i.e., at the previous line. + */ + if (0 + IF_HUSH_IF(|| reserved->res == RES_THEN) + IF_HUSH_IF(|| reserved->res == RES_ELIF) + IF_HUSH_IF(|| reserved->res == RES_ELSE) + IF_HUSH_LOOPS(|| reserved->res == RES_DO) + ) { + done_pipe(ctx, PIPE_SEQ); + } +# endif + o_reset_to_empty_unquoted(&ctx->word); + debug_printf_parse("done_word return %d\n", + (ctx->ctx_res_w == RES_SNTX)); + return (ctx->ctx_res_w == RES_SNTX); + } +# if defined(CMD_TEST2_SINGLEWORD_NOGLOB) + if (strcmp(ctx->word.data, "[[") == 0) { + command->cmd_type = CMD_TEST2_SINGLEWORD_NOGLOB; + } else +# endif +# if defined(CMD_SINGLEWORD_NOGLOB) + if (0 + /* In bash, local/export/readonly are special, args + * are assignments and therefore expansion of them + * should be "one-word" expansion: + * $ export i=`echo 'a b'` # one arg: "i=a b" + * compare with: + * $ ls i=`echo 'a b'` # two args: "i=a" and "b" + * ls: cannot access i=a: No such file or directory + * ls: cannot access b: No such file or directory + * Note: bash 3.2.33(1) does this only if export word + * itself is not quoted: + * $ export i=`echo 'aaa bbb'`; echo "$i" + * aaa bbb + * $ "export" i=`echo 'aaa bbb'`; echo "$i" + * aaa + */ + IF_HUSH_LOCAL( || strcmp(ctx->word.data, "local") == 0) + IF_HUSH_EXPORT( || strcmp(ctx->word.data, "export") == 0) + IF_HUSH_READONLY(|| strcmp(ctx->word.data, "readonly") == 0) + ) { + command->cmd_type = CMD_SINGLEWORD_NOGLOB; + } +# else + { /* empty block to pair "if ... else" */ } +# endif + } +#endif /* HAS_KEYWORDS */ + + if (command->group) { + /* "{ echo foo; } echo bar" - bad */ + syntax_error_at(ctx->word.data); + debug_printf_parse("done_word return 1: syntax error, " + "groups and arglists don't mix\n"); + return 1; + } + + /* If this word wasn't an assignment, next ones definitely + * can't be assignments. Even if they look like ones. */ + if (ctx->is_assignment != DEFINITELY_ASSIGNMENT + && ctx->is_assignment != WORD_IS_KEYWORD + ) { + ctx->is_assignment = NOT_ASSIGNMENT; + } else { + if (ctx->is_assignment == DEFINITELY_ASSIGNMENT) { + command->assignment_cnt++; + debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt); + } + debug_printf_parse("ctx->is_assignment was:'%s'\n", assignment_flag[ctx->is_assignment]); + ctx->is_assignment = MAYBE_ASSIGNMENT; + } + debug_printf_parse("ctx->is_assignment='%s'\n", assignment_flag[ctx->is_assignment]); + command->argv = add_string_to_strings(command->argv, xstrdup(ctx->word.data)); + debug_print_strings("word appended to argv", command->argv); + } + +#if ENABLE_HUSH_LOOPS + if (ctx->ctx_res_w == RES_FOR) { + if (ctx->word.has_quoted_part + || endofname(command->argv[0])[0] != '\0' + ) { + /* bash says just "not a valid identifier" */ + syntax_error("bad variable name in for"); + return 1; + } + /* Force FOR to have just one word (variable name) */ + /* NB: basically, this makes hush see "for v in ..." + * syntax as if it is "for v; in ...". FOR and IN become + * two pipe structs in parse tree. */ + done_pipe(ctx, PIPE_SEQ); + } +#endif +#if ENABLE_HUSH_CASE + /* Force CASE to have just one word */ + if (ctx->ctx_res_w == RES_CASE) { + done_pipe(ctx, PIPE_SEQ); + } +#endif + + o_reset_to_empty_unquoted(&ctx->word); + + debug_printf_parse("done_word return 0\n"); + return 0; +} + + +/* Peek ahead in the input to find out if we have a "&n" construct, + * as in "2>&1", that represents duplicating a file descriptor. + * Return: + * REDIRFD_CLOSE if >&- "close fd" construct is seen, + * REDIRFD_SYNTAX_ERR if syntax error, + * REDIRFD_TO_FILE if no & was seen, + * or the number found. + */ +#if BB_MMU +#define parse_redir_right_fd(as_string, input) \ + parse_redir_right_fd(input) +#endif +static int parse_redir_right_fd(o_string *as_string, struct in_str *input) +{ + int ch, d, ok; + + ch = i_peek(input); + if (ch != '&') + return REDIRFD_TO_FILE; + + ch = i_getch(input); /* get the & */ + nommu_addchr(as_string, ch); + ch = i_peek(input); + if (ch == '-') { + ch = i_getch(input); + nommu_addchr(as_string, ch); + return REDIRFD_CLOSE; + } + d = 0; + ok = 0; + while (ch != EOF && isdigit(ch)) { + d = d*10 + (ch-'0'); + ok = 1; + ch = i_getch(input); + nommu_addchr(as_string, ch); + ch = i_peek(input); + } + if (ok) return d; + +//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2) + + bb_simple_error_msg("ambiguous redirect"); + return REDIRFD_SYNTAX_ERR; +} + +/* Return code is 0 normal, 1 if a syntax error is detected + */ +static int parse_redirect(struct parse_context *ctx, + int fd, + redir_type style, + struct in_str *input) +{ + struct command *command = ctx->command; + struct redir_struct *redir; + struct redir_struct **redirp; + int dup_num; + + dup_num = REDIRFD_TO_FILE; + if (style != REDIRECT_HEREDOC) { + /* Check for a '>&1' type redirect */ + dup_num = parse_redir_right_fd(&ctx->as_string, input); + if (dup_num == REDIRFD_SYNTAX_ERR) + return 1; + } else { + int ch = i_peek_and_eat_bkslash_nl(input); + dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */ + if (dup_num) { /* <<-... */ + ch = i_getch(input); + nommu_addchr(&ctx->as_string, ch); + ch = i_peek(input); + } + } + + if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) { + int ch = i_peek_and_eat_bkslash_nl(input); + if (ch == '|') { + /* >|FILE redirect ("clobbering" >). + * Since we do not support "set -o noclobber" yet, + * >| and > are the same for now. Just eat |. + */ + ch = i_getch(input); + nommu_addchr(&ctx->as_string, ch); + } + } + + /* Create a new redir_struct and append it to the linked list */ + redirp = &command->redirects; + while ((redir = *redirp) != NULL) { + redirp = &(redir->next); + } + *redirp = redir = xzalloc(sizeof(*redir)); + /* redir->next = NULL; */ + /* redir->rd_filename = NULL; */ + redir->rd_type = style; + redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd; + + debug_printf_parse("redirect type %d %s\n", redir->rd_fd, + redir_table[style].descrip); + + redir->rd_dup = dup_num; + if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) { + /* Erik had a check here that the file descriptor in question + * is legit; I postpone that to "run time" + * A "-" representation of "close me" shows up as a -3 here */ + debug_printf_parse("duplicating redirect '%d>&%d'\n", + redir->rd_fd, redir->rd_dup); + } else { +#if 0 /* Instead we emit error message at run time */ + if (ctx->pending_redirect) { + /* For example, "cmd > <file" */ + syntax_error("invalid redirect"); + } +#endif + /* Set ctx->pending_redirect, so we know what to do at the + * end of the next parsed word. */ + ctx->pending_redirect = redir; + } + return 0; +} + +/* If a redirect is immediately preceded by a number, that number is + * supposed to tell which file descriptor to redirect. This routine + * looks for such preceding numbers. In an ideal world this routine + * needs to handle all the following classes of redirects... + * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo + * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo + * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo + * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo + * + * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html + * "2.7 Redirection + * ... If n is quoted, the number shall not be recognized as part of + * the redirection expression. For example: + * echo \2>a + * writes the character 2 into file a" + * We are getting it right by setting ->has_quoted_part on any <char> + * + * A -1 return means no valid number was found, + * the caller should use the appropriate default for this redirection. + */ +static int redirect_opt_num(o_string *o) +{ + int num; + + if (o->data == NULL) + return -1; + num = bb_strtou(o->data, NULL, 10); + if (errno || num < 0) + return -1; + o_reset_to_empty_unquoted(o); + return num; +} + +#if BB_MMU +#define fetch_till_str(as_string, input, word, skip_tabs) \ + fetch_till_str(input, word, skip_tabs) +#endif +static char *fetch_till_str(o_string *as_string, + struct in_str *input, + const char *word, + int heredoc_flags) +{ + o_string heredoc = NULL_O_STRING; + unsigned past_EOL; + int prev = 0; /* not \ */ + int ch; + + /* Starting with "" is necessary for this case: + * cat <<EOF + * + * xxx + * EOF + */ + heredoc.data = xzalloc(1); /* start as "", not as NULL */ + + goto jump_in; + + while (1) { + ch = i_getch(input); + if (ch != EOF) + nommu_addchr(as_string, ch); + if (ch == '\n' || ch == EOF) { + check_heredoc_end: + if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\') { + /* End-of-line, and not a line continuation */ + if (strcmp(heredoc.data + past_EOL, word) == 0) { + heredoc.data[past_EOL] = '\0'; + debug_printf_heredoc("parsed '%s' heredoc '%s'\n", word, heredoc.data); + return heredoc.data; + } + if (ch == '\n') { + /* This is a new line. + * Remember position and backslash-escaping status. + */ + o_addchr(&heredoc, ch); + prev = ch; + jump_in: + past_EOL = heredoc.length; + /* Get 1st char of next line, possibly skipping leading tabs */ + do { + ch = i_getch(input); + if (ch != EOF) + nommu_addchr(as_string, ch); + } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t'); + /* If this immediately ended the line, + * go back to end-of-line checks. + */ + if (ch == '\n') + goto check_heredoc_end; + } + } else { + /* Backslash-line continuation in an unquoted + * heredoc. This does not need special handling + * for heredoc body (unquoted heredocs are + * expanded on "execution" and that would take + * care of this case too), but not the case + * of line continuation *in terminator*: + * cat <<EOF + * Ok1 + * EO\ + * F + */ + heredoc.data[--heredoc.length] = '\0'; + prev = 0; /* not '' */ + continue; + } + } + if (ch == EOF) { + o_free(&heredoc); + return NULL; /* error */ + } + o_addchr(&heredoc, ch); + nommu_addchr(as_string, ch); + if (prev == '\' && ch == '\') + /* Correctly handle foo\<eol> (not a line cont.) */ + prev = 0; /* not '' */ + else + prev = ch; + } +} + +/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs + * and load them all. There should be exactly heredoc_cnt of them. + */ +#if BB_MMU +#define fetch_heredocs(as_string, pi, heredoc_cnt, input) \ + fetch_heredocs(pi, heredoc_cnt, input) +#endif +static int fetch_heredocs(o_string *as_string, struct pipe *pi, int heredoc_cnt, struct in_str *input) +{ + while (pi && heredoc_cnt) { + int i; + struct command *cmd = pi->cmds; + + debug_printf_heredoc("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n", + pi->num_cmds, + cmd->argv ? cmd->argv[0] : "NONE" + ); + for (i = 0; i < pi->num_cmds; i++) { + struct redir_struct *redir = cmd->redirects; + + debug_printf_heredoc("fetch_heredocs: %d cmd argv0:'%s'\n", + i, cmd->argv ? cmd->argv[0] : "NONE"); + while (redir) { + if (redir->rd_type == REDIRECT_HEREDOC) { + char *p; + + redir->rd_type = REDIRECT_HEREDOC2; + /* redir->rd_dup is (ab)used to indicate <<- */ + p = fetch_till_str(as_string, input, + redir->rd_filename, redir->rd_dup); + if (!p) { + syntax_error("unexpected EOF in here document"); + return -1; + } + free(redir->rd_filename); + redir->rd_filename = p; + heredoc_cnt--; + } + redir = redir->next; + } + if (cmd->group) { + //bb_error_msg("%s:%u heredoc_cnt:%d", __func__, __LINE__, heredoc_cnt); + heredoc_cnt = fetch_heredocs(as_string, cmd->group, heredoc_cnt, input); + //bb_error_msg("%s:%u heredoc_cnt:%d", __func__, __LINE__, heredoc_cnt); + if (heredoc_cnt < 0) + return heredoc_cnt; /* error */ + } + cmd++; + } + pi = pi->next; + } + return heredoc_cnt; +} + + +static int run_list(struct pipe *pi); +#if BB_MMU +#define parse_stream(pstring, heredoc_cnt_ptr, input, end_trigger) \ + parse_stream(heredoc_cnt_ptr, input, end_trigger) +#endif +static struct pipe *parse_stream(char **pstring, + int *heredoc_cnt_ptr, + struct in_str *input, + int end_trigger); + +/* Returns number of heredocs not yet consumed, + * or -1 on error. + */ +static int parse_group(struct parse_context *ctx, + struct in_str *input, int ch) +{ + /* ctx->word contains characters seen prior to ( or {. + * Typically it's empty, but for function defs, + * it contains function name (without '()'). */ +#if BB_MMU +# define as_string NULL +#else + char *as_string = NULL; +#endif + struct pipe *pipe_list; + int heredoc_cnt = 0; + int endch; + struct command *command = ctx->command; + + debug_printf_parse("parse_group entered\n"); +#if ENABLE_HUSH_FUNCTIONS + if (ch == '(' && !ctx->word.has_quoted_part) { + if (ctx->word.length) + if (done_word(ctx)) + return -1; + if (!command->argv) + goto skip; /* (... */ + if (command->argv[1]) { /* word word ... (... */ + syntax_error_unexpected_ch('('); + return -1; + } + /* it is "word(..." or "word (..." */ + do + ch = i_getch(input); + while (ch == ' ' || ch == '\t'); + if (ch != ')') { + syntax_error_unexpected_ch(ch); + return -1; + } + nommu_addchr(&ctx->as_string, ch); + do + ch = i_getch(input); + while (ch == ' ' || ch == '\t' || ch == '\n'); + if (ch != '{' && ch != '(') { + syntax_error_unexpected_ch(ch); + return -1; + } + nommu_addchr(&ctx->as_string, ch); + command->cmd_type = CMD_FUNCDEF; + goto skip; + } +#endif + +#if 0 /* Prevented by caller */ + if (command->argv /* word [word]{... */ + || ctx->word.length /* word{... */ + || ctx->word.has_quoted_part /* ""{... */ + ) { + syntax_error(NULL); + debug_printf_parse("parse_group return -1: " + "syntax error, groups and arglists don't mix\n"); + return -1; + } +#endif + + IF_HUSH_FUNCTIONS(skip:) + + endch = '}'; + if (ch == '(') { + endch = ')'; + IF_HUSH_FUNCTIONS(if (command->cmd_type != CMD_FUNCDEF)) + command->cmd_type = CMD_SUBSHELL; + } else { + /* bash does not allow "{echo...", requires whitespace */ + ch = i_peek(input); + if (ch != ' ' && ch != '\t' && ch != '\n' + && ch != '(' /* but "{(..." is allowed (without whitespace) */ + ) { + syntax_error_unexpected_ch(ch); + return -1; + } + if (ch != '(') { + ch = i_getch(input); + nommu_addchr(&ctx->as_string, ch); + } + } + + debug_printf_heredoc("calling parse_stream, heredoc_cnt:%d\n", heredoc_cnt); + pipe_list = parse_stream(&as_string, &heredoc_cnt, input, endch); + debug_printf_heredoc("parse_stream returned: heredoc_cnt:%d\n", heredoc_cnt); +#if !BB_MMU + if (as_string) + o_addstr(&ctx->as_string, as_string); +#endif + + /* empty ()/{} or parse error? */ + if (!pipe_list || pipe_list == ERR_PTR) { + /* parse_stream already emitted error msg */ + if (!BB_MMU) + free(as_string); + debug_printf_parse("parse_group return -1: " + "parse_stream returned %p\n", pipe_list); + return -1; + } +#if !BB_MMU + as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */ + command->group_as_string = as_string; + debug_printf_parse("end of group, remembering as:'%s'\n", + command->group_as_string); +#endif + +#if ENABLE_HUSH_FUNCTIONS + /* Convert "f() (cmds)" to "f() {(cmds)}" */ + if (command->cmd_type == CMD_FUNCDEF && endch == ')') { + struct command *cmd2; + + cmd2 = xzalloc(sizeof(*cmd2)); + cmd2->cmd_type = CMD_SUBSHELL; + cmd2->group = pipe_list; +# if !BB_MMU +//UNTESTED! + cmd2->group_as_string = command->group_as_string; + command->group_as_string = xasprintf("(%s)", command->group_as_string); +# endif + + pipe_list = new_pipe(); + pipe_list->cmds = cmd2; + pipe_list->num_cmds = 1; + } +#endif + + command->group = pipe_list; + + debug_printf_parse("parse_group return %d\n", heredoc_cnt); + return heredoc_cnt; + /* command remains "open", available for possible redirects */ +#undef as_string +} + +#if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS +/* Subroutines for copying $(...) and `...` things */ +/* '...' */ +static int add_till_single_quote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('''); + return 0; + } + if (ch == ''') + return 1; + o_addchr(dest, ch); + } +} +static int add_till_single_quote_dquoted(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('''); + return 0; + } + if (ch == ''') + return 1; + o_addqchr(dest, ch); + } +} +/* "..."...`..`...." - do we need to handle "...$(..)..." too? */ +static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote); +static int add_till_double_quote(o_string *dest, struct in_str *input) +{ + while (1) { + int ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch('"'); + return 0; + } + if (ch == '"') + return 1; + if (ch == '\') { /* \x. Copy both chars. */ + o_addchr(dest, ch); + ch = i_getch(input); + } + o_addchr(dest, ch); + if (ch == '`') { + if (!add_till_backquote(dest, input, /*in_dquote:*/ 1)) + return 0; + o_addchr(dest, ch); + continue; + } + //if (ch == '$') ... + } +} +/* Process `cmd` - copy contents until "`" is seen. Complicated by + * ` quoting. + * "Within the backquoted style of command substitution, backslash + * shall retain its literal meaning, except when followed by: '$', '`', or ''. + * The search for the matching backquote shall be satisfied by the first + * backquote found without a preceding backslash; during this search, + * if a non-escaped backquote is encountered within a shell comment, + * a here-document, an embedded command substitution of the $(command) + * form, or a quoted string, undefined results occur. A single-quoted + * or double-quoted string that begins, but does not end, within the + * "`...`" sequence produces undefined results." + * Example Output + * echo `echo ''TEST`echo ZZ`BEST` \TESTZZBEST + */ +static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote) +{ + while (1) { + int ch = i_getch(input); + if (ch == '`') + return 1; + if (ch == '\') { + /* \x. Copy both unless it is `, $, \ and maybe " */ + ch = i_getch(input); + if (ch != '`' + && ch != '$' + && ch != '\' + && (!in_dquote || ch != '"') + ) { + o_addchr(dest, '\'); + } + } + if (ch == EOF) { + syntax_error_unterm_ch('`'); + return 0; + } + o_addchr(dest, ch); + } +} +/* Process $(cmd) - copy contents until ")" is seen. Complicated by + * quoting and nested ()s. + * "With the $(command) style of command substitution, all characters + * following the open parenthesis to the matching closing parenthesis + * constitute the command. Any valid shell script can be used for command, + * except a script consisting solely of redirections which produces + * unspecified results." + * Example Output + * echo $(echo '(TEST)' BEST) (TEST) BEST + * echo $(echo 'TEST)' BEST) TEST) BEST + * echo $(echo ((TEST) BEST) ((TEST) BEST + * + * Also adapted to eat ${var%...} and $((...)) constructs, since ... part + * can contain arbitrary constructs, just like $(cmd). + * In bash compat mode, it needs to also be able to stop on ':' or '/' + * for ${var:N[:M]} and ${var/P[/R]} parsing. + */ +#define DOUBLE_CLOSE_CHAR_FLAG 0x80 +static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch) +{ + int ch; + char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG; +# if BASH_SUBSTR || BASH_PATTERN_SUBST + char end_char2 = end_ch >> 8; +# endif + end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1); + +# if ENABLE_HUSH_INTERACTIVE + G.promptmode = 1; /* PS2 */ +# endif + debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode); + + while (1) { + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch(end_ch); + return 0; + } + if (ch == end_ch +# if BASH_SUBSTR || BASH_PATTERN_SUBST + || ch == end_char2 +# endif + ) { + if (!dbl) + break; + /* we look for closing )) of $((EXPR)) */ + if (i_peek_and_eat_bkslash_nl(input) == end_ch) { + i_getch(input); /* eat second ')' */ + break; + } + } + o_addchr(dest, ch); + //bb_error_msg("%s:o_addchr('%c')", __func__, ch); + if (ch == '(' || ch == '{') { + ch = (ch == '(' ? ')' : '}'); + if (!add_till_closing_bracket(dest, input, ch)) + return 0; + o_addchr(dest, ch); + continue; + } + if (ch == ''') { + if (!add_till_single_quote(dest, input)) + return 0; + o_addchr(dest, ch); + continue; + } + if (ch == '"') { + if (!add_till_double_quote(dest, input)) + return 0; + o_addchr(dest, ch); + continue; + } + if (ch == '`') { + if (!add_till_backquote(dest, input, /*in_dquote:*/ 0)) + return 0; + o_addchr(dest, ch); + continue; + } + if (ch == '\') { + /* \x. Copy verbatim. Important for (, ) */ + ch = i_getch(input); + if (ch == EOF) { + syntax_error_unterm_ch(end_ch); + return 0; + } +# if 0 + if (ch == '\n') { + /* "backslash+newline", ignore both */ + o_delchr(dest); /* undo insertion of '' */ + continue; + } +# endif + o_addchr(dest, ch); + //bb_error_msg("%s:o_addchr('%c') after '\'", __func__, ch); + continue; + } + } + debug_printf_parse("%s return '%s' ch:'%c'\n", __func__, dest->data, ch); + return ch; +} +#endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */ + +#if BASH_DOLLAR_SQUOTE +/* Return code: 1 for "found and parsed", 0 for "seen something else" */ +# if BB_MMU +#define parse_dollar_squote(as_string, dest, input) \ + parse_dollar_squote(dest, input) +#define as_string NULL +# endif +static int parse_dollar_squote(o_string *as_string, o_string *dest, struct in_str *input) +{ + int start; + int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */ + debug_printf_parse("parse_dollar_squote entered: ch='%c'\n", ch); + if (ch != ''') + return 0; + + dest->has_quoted_part = 1; + start = dest->length; + + ch = i_getch(input); /* eat ' */ + nommu_addchr(as_string, ch); + while (1) { + ch = i_getch(input); + nommu_addchr(as_string, ch); + if (ch == EOF) { + syntax_error_unterm_ch('''); + return 0; + } + if (ch == ''') + break; + if (ch == SPECIAL_VAR_SYMBOL) { + /* Convert raw ^C to corresponding special variable reference */ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, SPECIAL_VAR_QUOTED_SVS); + /* will addchr() another SPECIAL_VAR_SYMBOL (see after the if() block) */ + } else if (ch == '\') { + static const char C_escapes[] ALIGN1 = "nrbtfav""x\01234567"; + + ch = i_getch(input); + nommu_addchr(as_string, ch); + if (strchr(C_escapes, ch)) { + char buf[4]; + char *p = buf; + int cnt = 2; + + buf[0] = ch; + if ((unsigned char)(ch - '0') <= 7) { /* \ooo */ + do { + ch = i_peek(input); + if ((unsigned char)(ch - '0') > 7) + break; + *++p = ch = i_getch(input); + nommu_addchr(as_string, ch); + } while (--cnt != 0); + } else if (ch == 'x') { /* \xHH */ + do { + ch = i_peek(input); + if (!isxdigit(ch)) + break; + *++p = ch = i_getch(input); + nommu_addchr(as_string, ch); + } while (--cnt != 0); + if (cnt == 2) { /* \x but next char is "bad" */ + ch = 'x'; + goto unrecognized; + } + } /* else simple seq like \ or \t */ + *++p = '\0'; + p = buf; + ch = bb_process_escape_sequence((void*)&p); + //bb_error_msg("buf:'%s' ch:%x", buf, ch); + if (ch == '\0') + continue; /* bash compat: $'...\0...' emits nothing */ + } else { /* unrecognized "\z": encode both chars unless ' or " */ + if (ch != ''' && ch != '"') { + unrecognized: + o_addqchr(dest, '\'); + } + } + } /* if (...) */ + o_addqchr(dest, ch); + } + + if (dest->length == start) { + /* $'', $'\0', $'\000\x00' and the like */ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } + + return 1; +# undef as_string +} +#else +# #define parse_dollar_squote(as_string, dest, input) 0 +#endif /* BASH_DOLLAR_SQUOTE */ + +/* Return code: 0 for OK, 1 for syntax error */ +#if BB_MMU +#define parse_dollar(as_string, dest, input, quote_mask) \ + parse_dollar(dest, input, quote_mask) +#define as_string NULL +#endif +static int parse_dollar(o_string *as_string, + o_string *dest, + struct in_str *input, unsigned char quote_mask) +{ + int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */ + + debug_printf_parse("parse_dollar entered: ch='%c' quote_mask:0x%x\n", ch, quote_mask); + if (isalpha(ch)) { + make_var: + ch = i_getch(input); + nommu_addchr(as_string, ch); + /*make_var1:*/ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + while (1) { + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + quote_mask = 0; + ch = i_peek_and_eat_bkslash_nl(input); + if (!isalnum(ch) && ch != '_') { + /* End of variable name reached */ + break; + } + ch = i_getch(input); + nommu_addchr(as_string, ch); + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } else if (isdigit(ch)) { + make_one_char_var: + ch = i_getch(input); + nommu_addchr(as_string, ch); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + debug_printf_parse(": '%c'\n", ch); + o_addchr(dest, ch | quote_mask); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } else switch (ch) { + case '$': /* pid */ + case '!': /* last bg pid */ + case '?': /* last exit code */ + case '#': /* number of args */ + case '*': /* args */ + case '@': /* args */ + case '-': /* $- option flags set by set builtin or shell options (-i etc) */ + goto make_one_char_var; + case '{': { + char len_single_ch; + + o_addchr(dest, SPECIAL_VAR_SYMBOL); + + ch = i_getch(input); /* eat '{' */ + nommu_addchr(as_string, ch); + + ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */ + /* It should be ${?}, or ${#var}, + * or even ${?+subst} - operator acting on a special variable, + * or the beginning of variable name. + */ + if (ch == EOF + || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */ + ) { + bad_dollar_syntax: + syntax_error_unterm_str("${name}"); + debug_printf_parse("parse_dollar return 0: unterminated ${name}\n"); + return 0; + } + nommu_addchr(as_string, ch); + len_single_ch = ch; + ch |= quote_mask; + + /* It's possible to just call add_till_closing_bracket() at this point. + * However, this regresses some of our testsuite cases + * which check invalid constructs like ${%}. + * Oh well... let's check that the var name part is fine... */ + + if (isdigit(len_single_ch) + || (len_single_ch == '#' && isdigit(i_peek_and_eat_bkslash_nl(input))) + ) { + /* Execution engine uses plain xatoi_positive() + * to interpret ${NNN} and {#NNN}, + * check syntax here in the parser. + * (bash does not support expressions in ${#NN}, + * e.g. ${#$var} and {#1:+WORD} are not supported). + */ + unsigned cnt = 9; /* max 9 digits for ${NN} and 8 for {#NN} */ + while (1) { + o_addchr(dest, ch); + debug_printf_parse(": '%c'\n", ch); + ch = i_getch_and_eat_bkslash_nl(input); + nommu_addchr(as_string, ch); + if (ch == '}') + break; + if (--cnt == 0) + goto bad_dollar_syntax; + if (len_single_ch != '#' && strchr(VAR_SUBST_OPS, ch)) + /* ${NN<op>...} is valid */ + goto eat_until_closing; + if (!isdigit(ch)) + goto bad_dollar_syntax; + } + } else + while (1) { + unsigned pos; + + o_addchr(dest, ch); + debug_printf_parse(": '%c'\n", ch); + + ch = i_getch(input); + nommu_addchr(as_string, ch); + if (ch == '}') + break; + if (!isalnum(ch) && ch != '_') { + unsigned end_ch; + unsigned char last_ch; + /* handle parameter expansions + * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_... + */ + if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */ + if (len_single_ch != '#' + /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */ + || i_peek(input) != '}' + ) { + goto bad_dollar_syntax; + } + /* else: it's "length of C" ${#C} op, + * where C is a single char + * special var name, e.g. ${#!}. + */ + } + eat_until_closing: + /* Eat everything until closing '}' (or ':') */ + end_ch = '}'; + if (BASH_SUBSTR + && ch == ':' + && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input)) + ) { + /* It's ${var:N[:M]} thing */ + end_ch = '}' * 0x100 + ':'; + } + if (BASH_PATTERN_SUBST + && ch == '/' + ) { + /* It's ${var/[/]pattern[/repl]} thing */ + if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */ + i_getch(input); + nommu_addchr(as_string, '/'); + ch = '\'; + } + end_ch = '}' * 0x100 + '/'; + } + o_addchr(dest, ch); + /* The pattern can't be empty. + * IOW: if the first char after "${v//" is a slash, + * it does not terminate the pattern - it's the first char of the pattern: + * v=/dev/ram; echo ${v////-} prints -dev-ram (pattern is "/") + * v=/dev/ram; echo ${v///r/-} prints /dev-am (pattern is "/r") + */ + if (i_peek(input) == '/') { + o_addchr(dest, i_getch(input)); + } + again: + if (!BB_MMU) + pos = dest->length; +#if ENABLE_HUSH_DOLLAR_OPS + last_ch = add_till_closing_bracket(dest, input, end_ch); + if (last_ch == 0) /* error? */ + return 0; +#else +# error Simple code to only allow ${var} is not implemented +#endif + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, last_ch); + } + + if ((BASH_SUBSTR || BASH_PATTERN_SUBST) + && (end_ch & 0xff00) + ) { + /* close the first block: */ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + /* while parsing N from ${var:N[:M]} + * or pattern from ${var/[/]pattern[/repl]} */ + if ((end_ch & 0xff) == last_ch) { + /* got ':' or '/'- parse the rest */ + end_ch = '}'; + goto again; + } + /* got '}' */ + if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') { + /* it's ${var:N} - emulate :999999999 */ + o_addstr(dest, "999999999"); + } /* else: it's ${var/[/]pattern} */ + } + break; + } + len_single_ch = 0; /* it can't be ${#C} op */ + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); + break; + } +#if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK + case '(': { + unsigned pos; + + ch = i_getch(input); + nommu_addchr(as_string, ch); +# if ENABLE_FEATURE_SH_MATH + if (i_peek_and_eat_bkslash_nl(input) == '(') { + ch = i_getch(input); + nommu_addchr(as_string, ch); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, quote_mask | '+'); + if (!BB_MMU) + pos = dest->length; + if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG)) + return 0; /* error */ + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, ')'); + o_addchr(as_string, ')'); + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); + break; + } +# endif +# if ENABLE_HUSH_TICK + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, quote_mask | '`'); + if (!BB_MMU) + pos = dest->length; + if (!add_till_closing_bracket(dest, input, ')')) + return 0; /* error */ + if (as_string) { + o_addstr(as_string, dest->data + pos); + o_addchr(as_string, ')'); + } + o_addchr(dest, SPECIAL_VAR_SYMBOL); +# endif + break; + } +#endif + case '_': + goto make_var; +#if 0 + /* TODO: $_: */ + /* $_ Shell or shell script name; or last argument of last command + * (if last command wasn't a pipe; if it was, bash sets $_ to ""); + * but in command's env, set to full pathname used to invoke it */ + ch = i_getch(input); + nommu_addchr(as_string, ch); + ch = i_peek_and_eat_bkslash_nl(input); + if (isalnum(ch)) { /* it's $_name or $_123 */ + ch = '_'; + goto make_var1; + } + /* else: it's $_ */ +#endif + default: + o_addQchr(dest, '$'); + } + debug_printf_parse("parse_dollar return 1 (ok)\n"); + return 1; +#undef as_string +} + +#if BB_MMU +#define encode_string(as_string, dest, input, dquote_end) \ + encode_string(dest, input, dquote_end) +#define as_string NULL +#endif +static int encode_string(o_string *as_string, + o_string *dest, + struct in_str *input, + int dquote_end) +{ + int ch; + int next; + + again: + ch = i_getch(input); + if (ch != EOF) + nommu_addchr(as_string, ch); + if (ch == dquote_end) { /* may be only '"' or EOF */ + debug_printf_parse("encode_string return 1 (ok)\n"); + return 1; + } + /* note: can't move it above ch == dquote_end check! */ + if (ch == EOF) { + syntax_error_unterm_ch('"'); + return 0; /* error */ + } + next = '\0'; + if (ch != '\n') { + next = i_peek(input); + } + debug_printf_parse("" ch=%c (%d) escape=%d\n", + ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)); + if (ch == '\') { + if (next == EOF) { + /* Testcase: in interactive shell a file with + * echo "unterminated string<eof> + * is sourced. + */ + syntax_error_unterm_ch('"'); + return 0; /* error */ + } + /* bash: + * "The backslash retains its special meaning [in "..."] + * only when followed by one of the following characters: + * $, `, ", , or <newline>. A double quote may be quoted + * within double quotes by preceding it with a backslash." + * NB: in (unquoted) heredoc, above does not apply to ", + * therefore we check for it by "next == dquote_end" cond. + */ + if (next == dquote_end || strchr("$`\\n", next)) { + ch = i_getch(input); /* eat next */ + if (ch == '\n') + goto again; /* skip <newline> */ + } /* else: ch remains == '\', and we double it below: */ + o_addqchr(dest, ch); /* \c if c is a glob char, else just c */ + nommu_addchr(as_string, ch); + goto again; + } + if (ch == '$') { + //if (parse_dollar_squote(as_string, dest, input)) + // goto again; + if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) { + debug_printf_parse("encode_string return 0: " + "parse_dollar returned 0 (error)\n"); + return 0; + } + goto again; + } +#if ENABLE_HUSH_TICK + if (ch == '`') { + //unsigned pos = dest->length; + o_addchr(dest, SPECIAL_VAR_SYMBOL); + o_addchr(dest, 0x80 | '`'); + if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"')) + return 0; /* error */ + o_addchr(dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos); + goto again; + } +#endif + o_addQchr(dest, ch); + if (ch == SPECIAL_VAR_SYMBOL) { + /* Convert "^C" to corresponding special variable reference */ + o_addchr(dest, SPECIAL_VAR_QUOTED_SVS); + o_addchr(dest, SPECIAL_VAR_SYMBOL); + } + goto again; +#undef as_string +} + +/* + * Scan input until EOF or end_trigger char. + * Return a list of pipes to execute, or NULL on EOF + * or if end_trigger character is met. + * On syntax error, exit if shell is not interactive, + * reset parsing machinery and start parsing anew, + * or return ERR_PTR. + */ +static struct pipe *parse_stream(char **pstring, + int *heredoc_cnt_ptr, + struct in_str *input, + int end_trigger) +{ + struct parse_context ctx; + int heredoc_cnt; + + /* Single-quote triggers a bypass of the main loop until its mate is + * found. When recursing, quote state is passed in via ctx.word.o_expflags. + */ + debug_printf_parse("parse_stream entered, end_trigger='%c'\n", + end_trigger ? end_trigger : 'X'); + debug_enter(); + + initialize_context(&ctx); + + /* If very first arg is "" or '', ctx.word.data may end up NULL. + * Preventing this: + */ + ctx.word.data = xzalloc(1); /* start as "", not as NULL */ + + /* We used to separate words on $IFS here. This was wrong. + * $IFS is used only for word splitting when $var is expanded, + * here we should use blank chars as separators, not $IFS + */ + + heredoc_cnt = 0; + while (1) { + const char *is_blank; + const char *is_special; + int ch; + int next; + int redir_fd; + redir_type redir_style; + + ch = i_getch(input); + debug_printf_parse(": ch=%c (%d) escape=%d\n", + ch, ch, !!(ctx.word.o_expflags & EXP_FLAG_ESC_GLOB_CHARS)); + if (ch == EOF) { + struct pipe *pi; + + if (heredoc_cnt) { + syntax_error_unterm_str("here document"); + goto parse_error_exitcode1; + } + if (end_trigger == ')') { + syntax_error_unterm_ch('('); + goto parse_error_exitcode1; + } + if (end_trigger == '}') { + syntax_error_unterm_ch('{'); + goto parse_error_exitcode1; + } + + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } + o_free_and_set_NULL(&ctx.word); + done_pipe(&ctx, PIPE_SEQ); + pi = ctx.list_head; + /* If we got nothing... */ + /* (this makes bare "&" cmd a no-op. + * bash says: "syntax error near unexpected token '&'") */ + if (pi->num_cmds == 0 + IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE) + ) { + free_pipe_list(pi); + pi = NULL; + } +#if !BB_MMU + debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data); + if (pstring) + *pstring = ctx.as_string.data; + else + o_free(&ctx.as_string); +#endif + // heredoc_cnt must be 0 here anyway + //if (heredoc_cnt_ptr) + // *heredoc_cnt_ptr = heredoc_cnt; + debug_leave(); + debug_printf_heredoc("parse_stream return heredoc_cnt:%d\n", heredoc_cnt); + debug_printf_parse("parse_stream return %p\n", pi); + return pi; + } + + /* Handle "'" and "" first, as they won't play nice with + * i_peek_and_eat_bkslash_nl() anyway: + * echo z\ + * and + * echo '\ + * ' + * would break. + */ + if (ch == '\') { + ch = i_getch(input); + if (ch == '\n') + continue; /* drop <newline>, get next char */ + nommu_addchr(&ctx.as_string, '\'); + if (ch == SPECIAL_VAR_SYMBOL) { + nommu_addchr(&ctx.as_string, ch); + /* Convert ^C to corresponding special variable reference */ + goto case_SPECIAL_VAR_SYMBOL; + } + o_addchr(&ctx.word, '\'); + if (ch == EOF) { + /* Testcase: eval 'echo Ok' */ + /* bash-4.3.43 was removing backslash, + * but 4.4.19 retains it, most other shells too + */ + continue; /* get next char */ + } + /* Example: echo Hello \2>file + * we need to know that word 2 is quoted + */ + ctx.word.has_quoted_part = 1; + nommu_addchr(&ctx.as_string, ch); + o_addchr(&ctx.word, ch); + continue; /* get next char */ + } + nommu_addchr(&ctx.as_string, ch); + if (ch == ''') { + ctx.word.has_quoted_part = 1; + next = i_getch(input); + if (next == ''' && !ctx.pending_redirect) + goto insert_empty_quoted_str_marker; + + ch = next; + while (1) { + if (ch == EOF) { + syntax_error_unterm_ch('''); + goto parse_error_exitcode1; + } + nommu_addchr(&ctx.as_string, ch); + if (ch == ''') + break; + if (ch == SPECIAL_VAR_SYMBOL) { + /* Convert raw ^C to corresponding special variable reference */ + o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL); + o_addchr(&ctx.word, SPECIAL_VAR_QUOTED_SVS); + } + o_addqchr(&ctx.word, ch); + ch = i_getch(input); + } + continue; /* get next char */ + } + + next = '\0'; + if (ch != '\n') + next = i_peek_and_eat_bkslash_nl(input); + + is_special = "{}<>&|();#" /* special outside of "str" */ + "$"" IF_HUSH_TICK("`") /* always special */ + SPECIAL_VAR_SYMBOL_STR; +#if defined(CMD_TEST2_SINGLEWORD_NOGLOB) + if (ctx.command->cmd_type == CMD_TEST2_SINGLEWORD_NOGLOB) { + /* In [[ ]], {}<>&|() are not special */ + is_special += 8; + } else +#endif + /* Are { and } special here? */ + if (ctx.command->argv /* word [word]{... - non-special */ + || ctx.word.length /* word{... - non-special */ + || ctx.word.has_quoted_part /* ""{... - non-special */ + || (next != ';' /* }; - special */ + && next != ')' /* }) - special */ + && next != '(' /* {( - special */ + && next != '&' /* }& and }&& ... - special */ + && next != '|' /* }|| ... - special */ + && !strchr(defifs, next) /* {word - non-special */ + ) + ) { + /* They are not special, skip "{}" */ + is_special += 2; + } + is_special = strchr(is_special, ch); + is_blank = strchr(defifs, ch); + + if (!is_special && !is_blank) { /* ordinary char */ + ordinary_char: + o_addQchr(&ctx.word, ch); + if ((ctx.is_assignment == MAYBE_ASSIGNMENT + || ctx.is_assignment == WORD_IS_KEYWORD) + && ch == '=' + && endofname(ctx.word.data)[0] == '=' + ) { + ctx.is_assignment = DEFINITELY_ASSIGNMENT; + debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); + } + continue; + } + + if (is_blank) { +#if ENABLE_HUSH_LINENO_VAR +/* Case: + * "while ...; do<whitespace><newline> + * cmd ..." + * would think that "cmd" starts in <whitespace> - + * i.e., at the previous line. + * We need to skip all whitespace before newlines. + */ + while (ch != '\n') { + next = i_peek(input); + if (next != ' ' && next != '\t' && next != '\n') + break; /* next char is not ws */ + ch = i_getch(input); + } + /* ch == last eaten whitespace char */ +#endif + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } + if (ch == '\n') { + /* Is this a case when newline is simply ignored? + * Some examples: + * "cmd | <newline> cmd ..." + * "case ... in <newline> word) ..." + */ + if (IS_NULL_CMD(ctx.command) + && ctx.word.length == 0 + && !ctx.word.has_quoted_part + && heredoc_cnt == 0 + ) { + /* This newline can be ignored. But... + * Without check #1, interactive shell + * ignores even bare <newline>, + * and shows the continuation prompt: + * ps1_prompt$ <enter> + * ps2> _ <=== wrong, should be ps1 + * Without check #2, "cmd & <newline>" + * is similarly mistreated. + * (BTW, this makes "cmd & cmd" + * and "cmd && cmd" non-orthogonal. + * Really, ask yourself, why + * "cmd && <newline>" doesn't start + * cmd but waits for more input? + * The only reason is that it might be + * a "cmd1 && <nl> cmd2 &" construct, + * cmd1 may need to run in BG). + */ + struct pipe *pi = ctx.list_head; + if (pi->num_cmds != 0 /* check #1 */ + && pi->followup != PIPE_BG /* check #2 */ + ) { + continue; + } + } + /* Treat newline as a command separator. */ + done_pipe(&ctx, PIPE_SEQ); + debug_printf_heredoc("heredoc_cnt:%d\n", heredoc_cnt); + if (heredoc_cnt) { + heredoc_cnt = fetch_heredocs(&ctx.as_string, ctx.list_head, heredoc_cnt, input); + if (heredoc_cnt != 0) + goto parse_error_exitcode1; + } + ctx.is_assignment = MAYBE_ASSIGNMENT; + debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); + ch = ';'; + /* note: if (is_blank) continue; + * will still trigger for us */ + } + } + + /* "cmd}" or "cmd }..." without semicolon or &: + * } is an ordinary char in this case, even inside { cmd; } + * Pathological example: { ""}; } should exec "}" cmd + */ + if (ch == '}') { + if (ctx.word.length != 0 /* word} */ + || ctx.word.has_quoted_part /* ""} */ + ) { + goto ordinary_char; + } + if (!IS_NULL_CMD(ctx.command)) { /* cmd } */ + /* Generally, there should be semicolon: "cmd; }" + * However, bash allows to omit it if "cmd" is + * a group. Examples: + * { { echo 1; } } + * {(echo 1)} + * { echo 0 >&2 | { echo 1; } } + * { while false; do :; done } + * { case a in b) ;; esac } + */ + if (ctx.command->group) + goto term_group; + goto ordinary_char; + } + if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */ + /* Can't be an end of {cmd}, skip the check */ + goto skip_end_trigger; + /* else: } does terminate a group */ + } + term_group: + if (end_trigger && end_trigger == ch + && (ch != ';' || heredoc_cnt == 0) +#if ENABLE_HUSH_CASE + && (ch != ')' + || ctx.ctx_res_w != RES_MATCH + || (!ctx.word.has_quoted_part && strcmp(ctx.word.data, "esac") == 0) + ) +#endif + ) { + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } + done_pipe(&ctx, PIPE_SEQ); + ctx.is_assignment = MAYBE_ASSIGNMENT; + debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); + /* Do we sit outside of any if's, loops or case's? */ + if (!HAS_KEYWORDS + IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0)) + ) { + o_free_and_set_NULL(&ctx.word); +#if !BB_MMU + debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data); + if (pstring) + *pstring = ctx.as_string.data; + else + o_free(&ctx.as_string); +#endif + if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) { + /* Example: bare "{ }", "()" */ + G.last_exitcode = 2; /* bash compat */ + syntax_error_unexpected_ch(ch); + goto parse_error; + } + if (heredoc_cnt_ptr) + *heredoc_cnt_ptr = heredoc_cnt; + debug_printf_heredoc("parse_stream return heredoc_cnt:%d\n", heredoc_cnt); + debug_printf_parse("parse_stream return %p: " + "end_trigger char found\n", + ctx.list_head); + debug_leave(); + return ctx.list_head; + } + } + + if (is_blank) + continue; + + /* Catch <, > before deciding whether this word is + * an assignment. a=1 2>z b=2: b=2 is still assignment */ + switch (ch) { + case '>': + redir_fd = redirect_opt_num(&ctx.word); + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } + redir_style = REDIRECT_OVERWRITE; + if (next == '>') { + redir_style = REDIRECT_APPEND; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } +#if 0 + else if (next == '(') { + syntax_error(">(process) not supported"); + goto parse_error_exitcode1; + } +#endif + if (parse_redirect(&ctx, redir_fd, redir_style, input)) + goto parse_error_exitcode1; + continue; /* get next char */ + case '<': + redir_fd = redirect_opt_num(&ctx.word); + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } + redir_style = REDIRECT_INPUT; + if (next == '<') { + redir_style = REDIRECT_HEREDOC; + heredoc_cnt++; + debug_printf_heredoc("++heredoc_cnt=%d\n", heredoc_cnt); + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } else if (next == '>') { + redir_style = REDIRECT_IO; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + } +#if 0 + else if (next == '(') { + syntax_error("<(process) not supported"); + goto parse_error_exitcode1; + } +#endif + if (parse_redirect(&ctx, redir_fd, redir_style, input)) + goto parse_error_exitcode1; + continue; /* get next char */ + case '#': + if (ctx.word.length == 0 && !ctx.word.has_quoted_part) { + /* skip "#comment" */ + /* note: we do not add it to &ctx.as_string */ +/* TODO: in bash: + * comment inside $() goes to the next \n, even inside quoted string (!): + * cmd "$(cmd2 #comment)" - syntax error + * cmd "`cmd2 #comment`" - ok + * We accept both (comment ends where command subst ends, in both cases). + */ + while (1) { + ch = i_peek(input); + if (ch == '\n') { + nommu_addchr(&ctx.as_string, '\n'); + break; + } + ch = i_getch(input); + if (ch == EOF) + break; + } + continue; /* get next char */ + } + break; + } + skip_end_trigger: + + if (ctx.is_assignment == MAYBE_ASSIGNMENT + /* check that we are not in word in "a=1 2>word b=1": */ + && !ctx.pending_redirect + ) { + /* ch is a special char and thus this word + * cannot be an assignment */ + ctx.is_assignment = NOT_ASSIGNMENT; + debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); + } + + /* Note: nommu_addchr(&ctx.as_string, ch) is already done */ + + switch (ch) { + case_SPECIAL_VAR_SYMBOL: + case SPECIAL_VAR_SYMBOL: + /* Convert raw ^C to corresponding special variable reference */ + o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL); + o_addchr(&ctx.word, SPECIAL_VAR_QUOTED_SVS); + /* fall through */ + case '#': + /* non-comment #: "echo a#b" etc */ + o_addchr(&ctx.word, ch); + continue; /* get next char */ + case '$': + if (parse_dollar_squote(&ctx.as_string, &ctx.word, input)) + continue; /* get next char */ + if (!parse_dollar(&ctx.as_string, &ctx.word, input, /*quote_mask:*/ 0)) { + debug_printf_parse("parse_stream parse error: " + "parse_dollar returned 0 (error)\n"); + goto parse_error_exitcode1; + } + continue; /* get next char */ + case '"': + ctx.word.has_quoted_part = 1; + if (next == '"' && !ctx.pending_redirect) { + i_getch(input); /* eat second " */ + insert_empty_quoted_str_marker: + nommu_addchr(&ctx.as_string, next); + o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL); + o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL); + continue; /* get next char */ + } + if (ctx.is_assignment == NOT_ASSIGNMENT) + ctx.word.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS; + if (!encode_string(&ctx.as_string, &ctx.word, input, '"')) + goto parse_error_exitcode1; + ctx.word.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS; + continue; /* get next char */ +#if ENABLE_HUSH_TICK + case '`': { + USE_FOR_NOMMU(unsigned pos;) + + o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL); + o_addchr(&ctx.word, '`'); + USE_FOR_NOMMU(pos = ctx.word.length;) + if (!add_till_backquote(&ctx.word, input, /*in_dquote:*/ 0)) + goto parse_error_exitcode1; +# if !BB_MMU + o_addstr(&ctx.as_string, ctx.word.data + pos); + o_addchr(&ctx.as_string, '`'); +# endif + o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", ctx.word.data + pos); + continue; /* get next char */ + } +#endif + case ';': +#if ENABLE_HUSH_CASE + case_semi: +#endif + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } + done_pipe(&ctx, PIPE_SEQ); +#if ENABLE_HUSH_CASE + /* Eat multiple semicolons, detect + * whether it means something special */ + while (1) { + ch = i_peek_and_eat_bkslash_nl(input); + if (ch != ';') + break; + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + if (ctx.ctx_res_w == RES_CASE_BODY) { + ctx.ctx_dsemicolon = 1; + ctx.ctx_res_w = RES_MATCH; + break; + } + } +#endif + new_cmd: + /* We just finished a cmd. New one may start + * with an assignment */ + ctx.is_assignment = MAYBE_ASSIGNMENT; + debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]); + continue; /* get next char */ + case '&': + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } + if (next == '&') { + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + done_pipe(&ctx, PIPE_AND); + } else { + done_pipe(&ctx, PIPE_BG); + } + goto new_cmd; + case '|': + if (done_word(&ctx)) { + goto parse_error_exitcode1; + } +#if ENABLE_HUSH_CASE + if (ctx.ctx_res_w == RES_MATCH) + break; /* we are in case's "word | word)" */ +#endif + if (next == '|') { /* || */ + ch = i_getch(input); + nommu_addchr(&ctx.as_string, ch); + done_pipe(&ctx, PIPE_OR); + } else { + /* we could pick up a file descriptor choice here + * with redirect_opt_num(), but bash doesn't do it. + * "echo foo 2| cat" yields "foo 2". */ + done_command(&ctx); + } + goto new_cmd; + case '(': +#if ENABLE_HUSH_CASE + /* "case... in [(]word)..." - skip '(' */ + if (ctx.ctx_res_w == RES_MATCH + && ctx.command->argv == NULL /* not (word|(... */ + && ctx.word.length == 0 /* not word(... */ + && ctx.word.has_quoted_part == 0 /* not ""(... */ + ) { + continue; /* get next char */ + } +#endif + /* fall through */ + case '{': { + int n = parse_group(&ctx, input, ch); + if (n < 0) { + goto parse_error_exitcode1; + } + debug_printf_heredoc("parse_group done, needs heredocs:%d\n", n); + heredoc_cnt += n; + goto new_cmd; + } + case ')': +#if ENABLE_HUSH_CASE + if (ctx.ctx_res_w == RES_MATCH) + goto case_semi; +#endif + case '}': + /* proper use of this character is caught by end_trigger: + * if we see {, we call parse_group(..., end_trigger='}') + * and it will match } earlier (not here). */ + G.last_exitcode = 2; + syntax_error_unexpected_ch(ch); + goto parse_error; + default: + if (HUSH_DEBUG) + bb_error_msg_and_die("BUG: unexpected %c", ch); + } + } /* while (1) */ + + parse_error_exitcode1: + G.last_exitcode = 1; + parse_error: + { + struct parse_context *pctx; + IF_HAS_KEYWORDS(struct parse_context *p2;) + + /* Clean up allocated tree. + * Sample for finding leaks on syntax error recovery path. + * Run it from interactive shell, watch pmap `pidof hush`. + * while if false; then false; fi; do break; fi + * Samples to catch leaks at execution: + * while if (true | { true;}); then echo ok; fi; do break; done + * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done + */ + pctx = &ctx; + do { + /* Update pipe/command counts, + * otherwise freeing may miss some */ + done_pipe(pctx, PIPE_SEQ); + debug_printf_clean("freeing list %p from ctx %p\n", + pctx->list_head, pctx); + debug_print_tree(pctx->list_head, 0); + free_pipe_list(pctx->list_head); + debug_printf_clean("freed list %p\n", pctx->list_head); +#if !BB_MMU + o_free(&pctx->as_string); +#endif + IF_HAS_KEYWORDS(p2 = pctx->stack;) + if (pctx != &ctx) { + free(pctx); + } + IF_HAS_KEYWORDS(pctx = p2;) + } while (HAS_KEYWORDS && pctx); + + o_free(&ctx.word); +#if !BB_MMU + if (pstring) + *pstring = NULL; +#endif + debug_leave(); + return ERR_PTR; + } +} + + +/*** Execution routines ***/ + +/* Expansion can recurse, need forward decls: */ +#if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE +#define expand_string_to_string(str, EXP_flags, do_unbackslash) \ + expand_string_to_string(str) +#endif +static char *expand_string_to_string(const char *str, int EXP_flags, int do_unbackslash); +#if ENABLE_HUSH_TICK +static int process_command_subs(o_string *dest, const char *s); +#endif +static int expand_vars_to_list(o_string *output, int n, char *arg); + +/* expand_strvec_to_strvec() takes a list of strings, expands + * all variable references within and returns a pointer to + * a list of expanded strings, possibly with larger number + * of strings. (Think VAR="a b"; echo $VAR). + * This new list is allocated as a single malloc block. + * NULL-terminated list of char* pointers is at the beginning of it, + * followed by strings themselves. + * Caller can deallocate entire list by single free(list). */ + +/* A horde of its helpers come first: */ + +static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len) +{ + while (--len >= 0) { + char c = *str++; + +#if ENABLE_HUSH_BRACE_EXPANSION + if (c == '{' || c == '}') { + /* { -> {, } -> } */ + o_addchr(o, '\'); + /* And now we want to add { or } and continue: + * o_addchr(o, c); + * continue; + * luckily, just falling through achieves this. + */ + } +#endif + o_addchr(o, c); + if (c == '\') { + /* \z -> \\z; <eol> -> \<eol> */ + o_addchr(o, '\'); + if (len) { + len--; + o_addchr(o, '\'); + o_addchr(o, *str++); + } + } + } +} + +/* Store given string, finalizing the word and starting new one whenever + * we encounter IFS char(s). This is used for expanding variable values. + * End-of-string does NOT finalize word: think about 'echo -$VAR-'. + * Return in output->ended_in_ifs: + * 1 - ended with IFS char, else 0 (this includes case of empty str). + */ +static int expand_on_ifs(o_string *output, int n, const char *str) +{ + int last_is_ifs = 0; + + while (1) { + int word_len; + + if (!*str) /* EOL - do not finalize word */ + break; + word_len = strcspn(str, G.ifs); + if (word_len) { + /* We have WORD_LEN leading non-IFS chars */ + if (!(output->o_expflags & EXP_FLAG_GLOB)) { + o_addblock(output, str, word_len); + } else { + /* Protect backslashes against globbing up :) + * Example: "v='*'; echo b$v" prints "b*" + * (and does not try to glob on "*") + */ + o_addblock_duplicate_backslash(output, str, word_len); + /*/ Why can't we do it easier? */ + /*o_addblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of "Z*" */ + /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */ + } + last_is_ifs = 0; + str += word_len; + if (!*str) /* EOL - do not finalize word */ + break; + } + + /* We know str here points to at least one IFS char */ + last_is_ifs = 1; + str += strspn(str, G.ifs_whitespace); /* skip IFS whitespace chars */ + if (!*str) /* EOL - do not finalize word */ + break; + + if (G.ifs_whitespace != G.ifs /* usually false ($IFS is usually all whitespace), */ + && strchr(G.ifs, *str) /* the second check would fail */ + ) { + /* This is a non-whitespace $IFS char */ + /* Skip it and IFS whitespace chars, start new word */ + str++; + str += strspn(str, G.ifs_whitespace); + goto new_word; + } + + /* Start new word... but not always! */ + /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */ + if (output->has_quoted_part + /* + * Case "v=' a'; echo $v": + * here nothing precedes the space in $v expansion, + * therefore we should not finish the word + * (IOW: if there *is* word to finalize, only then do it): + * It's okay if this accesses the byte before first argv[]: + * past call to o_save_ptr() cleared it to zero byte + * (grep for -prev-ifs-check-). + */ + || output->data[output->length - 1] + ) { + new_word: + o_addchr(output, '\0'); + debug_print_list("expand_on_ifs", output, n); + n = o_save_ptr(output, n); + } + } + + output->ended_in_ifs = last_is_ifs; + debug_print_list("expand_on_ifs[1]", output, n); + return n; +} + +/* Helper to expand $((...)) and heredoc body. These act as if + * they are in double quotes, with the exception that they are not :). + * Just the rules are similar: "expand only $var and `cmd`" + * + * Returns malloced string. + * As an optimization, we return NULL if expansion is not needed. + */ +static char *encode_then_expand_string(const char *str) +{ + char *exp_str; + struct in_str input; + o_string dest = NULL_O_STRING; + const char *cp; + + cp = str; + for (;;) { + if (!*cp) return NULL; /* string has no special chars */ + if (*cp == '$') break; + if (*cp == '\') break; +#if ENABLE_HUSH_TICK + if (*cp == '`') break; +#endif + cp++; + } + + /* We need to expand. Example: + * echo $(($a + `echo 1`)) $((1 + $((2)) )) + */ + setup_string_in_str(&input, str); + encode_string(NULL, &dest, &input, EOF); +//TODO: error check (encode_string returns 0 on error)? + //bb_error_msg("'%s' -> '%s'", str, dest.data); + exp_str = expand_string_to_string(dest.data, + EXP_FLAG_ESC_GLOB_CHARS, + /*unbackslash:*/ 1 + ); + //bb_error_msg("'%s' -> '%s'", dest.data, exp_str); + o_free(&dest); + return exp_str; +} + +static const char *first_special_char_in_vararg(const char *cp) +{ + for (;;) { + if (!*cp) return NULL; /* string has no special chars */ + if (*cp == '$') return cp; + if (*cp == '\') return cp; + if (*cp == ''') return cp; + if (*cp == '"') return cp; +#if ENABLE_HUSH_TICK + if (*cp == '`') return cp; +#endif + /* dquoted "${x:+ARG}" should not glob, therefore + * '*' et al require some non-literal processing: */ + if (*cp == '*') return cp; + if (*cp == '?') return cp; + if (*cp == '[') return cp; + cp++; + } +} + +/* Expanding ARG in ${var#ARG}, ${var%ARG}, or ${var/ARG/ARG}. + * These can contain single- and double-quoted strings, + * and treated as if the ARG string is initially unquoted. IOW: + * ${var#ARG} and "${var#ARG}" treat ARG the same (ARG can even be + * a dquoted string: "${var#"zz"}"), the difference only comes later + * (word splitting and globbing of the ${var...} result). + */ +#if !BASH_PATTERN_SUBST +#define encode_then_expand_vararg(str, handle_squotes, do_unbackslash) \ + encode_then_expand_vararg(str, handle_squotes) +#endif +static char *encode_then_expand_vararg(const char *str, int handle_squotes, int do_unbackslash) +{ +#if !BASH_PATTERN_SUBST && ENABLE_HUSH_CASE + const int do_unbackslash = 0; +#endif + char *exp_str; + struct in_str input; + o_string dest = NULL_O_STRING; + + if (!first_special_char_in_vararg(str)) { + /* string has no special chars */ + return NULL; + } + + setup_string_in_str(&input, str); + dest.data = xzalloc(1); /* start as "", not as NULL */ + exp_str = NULL; + + for (;;) { + int ch; + + ch = i_getch(&input); + debug_printf_parse("%s: ch=%c (%d) escape=%d\n", + __func__, ch, ch, !!dest.o_expflags); + + if (!dest.o_expflags) { + if (ch == EOF) + break; + if (handle_squotes && ch == ''') { + if (!add_till_single_quote_dquoted(&dest, &input)) + goto ret; /* error */ + continue; + } + } + if (ch == EOF) { + syntax_error_unterm_ch('"'); + goto ret; /* error */ + } + if (ch == '"') { + dest.o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS; + continue; + } + if (ch == '\') { + ch = i_getch(&input); + if (ch == EOF) { +//example? error message? syntax_error_unterm_ch('"'); + debug_printf_parse("%s: error: \<eof>\n", __func__); + goto ret; + } + o_addqchr(&dest, ch); + continue; + } + if (ch == '$') { + if (parse_dollar_squote(NULL, &dest, &input)) + continue; + if (!parse_dollar(NULL, &dest, &input, /*quote_mask:*/ 0x80)) { + debug_printf_parse("%s: error: parse_dollar returned 0 (error)\n", __func__); + goto ret; + } + continue; + } +#if ENABLE_HUSH_TICK + if (ch == '`') { + //unsigned pos = dest->length; + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + o_addchr(&dest, 0x80 | '`'); + if (!add_till_backquote(&dest, &input, + /*in_dquote:*/ dest.o_expflags /* nonzero if EXP_FLAG_ESC_GLOB_CHARS set */ + ) + ) { + goto ret; /* error */ + } + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos); + continue; + } +#endif + o_addQchr(&dest, ch); + } /* for (;;) */ + + debug_printf_parse("encode: '%s' -> '%s'\n", str, dest.data); + exp_str = expand_string_to_string(dest.data, + do_unbackslash ? EXP_FLAG_ESC_GLOB_CHARS : 0, + do_unbackslash + ); + ret: + debug_printf_parse("expand: '%s' -> '%s'\n", dest.data, exp_str); + o_free(&dest); + return exp_str; +} + +/* Expanding ARG in ${var+ARG}, ${var-ARG} + */ +static int encode_then_append_var_plusminus(o_string *output, int n, + char *str, int dquoted) +{ + struct in_str input; + o_string dest = NULL_O_STRING; + + if (!first_special_char_in_vararg(str) + && '\0' == str[strcspn(str, G.ifs)] + ) { + /* string has no special chars + * && string has no $IFS chars + */ + if (dquoted) { + /* Prints 1 (quoted expansion is a "" word, not nothing): + * set -- "${notexist-}"; echo $# + */ + output->has_quoted_part = 1; + } + return expand_vars_to_list(output, n, str); + } + + setup_string_in_str(&input, str); + + for (;;) { + int ch; + + ch = i_getch(&input); + debug_printf_parse("%s: ch=%c (%d) escape=%x\n", + __func__, ch, ch, dest.o_expflags); + + if (!dest.o_expflags) { + if (ch == EOF) + break; + if (!dquoted && strchr(G.ifs, ch)) { + /* PREFIX${x:d${e}f ...} and we met space: expand "d${e}f" and start new word. + * do not assume we are at the start of the word (PREFIX above). + */ + if (dest.data) { + n = expand_vars_to_list(output, n, dest.data); + o_free_and_set_NULL(&dest); + o_addchr(output, '\0'); + n = o_save_ptr(output, n); /* create next word */ + } else + if (output->length != o_get_last_ptr(output, n) + || output->has_quoted_part + ) { + /* For these cases: + * f() { for i; do echo "|$i|"; done; }; x=x + * f a${x:+ }b # 1st condition + * |a| + * |b| + * f ""${x:+ }b # 2nd condition + * || + * |b| + */ + o_addchr(output, '\0'); + n = o_save_ptr(output, n); /* create next word */ + } + continue; + } + if (!dquoted && ch == ''') { + if (!add_till_single_quote_dquoted(&dest, &input)) + goto ret; /* error */ + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + continue; + } + } + if (ch == EOF) { + syntax_error_unterm_ch('"'); + goto ret; /* error */ + } + if (ch == '"') { + dest.o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS; + if (dest.o_expflags) { + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + } + continue; + } + if (ch == '\') { + ch = i_getch(&input); + if (ch == EOF) { +//example? error message? syntax_error_unterm_ch('"'); + debug_printf_parse("%s: error: \<eof>\n", __func__); + goto ret; + } + o_addqchr(&dest, ch); + continue; + } + if (ch == '$') { + if (!parse_dollar(NULL, &dest, &input, /*quote_mask:*/ (dest.o_expflags || dquoted) ? 0x80 : 0)) { + debug_printf_parse("%s: error: parse_dollar returned 0 (error)\n", __func__); + goto ret; + } + continue; + } +#if ENABLE_HUSH_TICK + if (ch == '`') { + //unsigned pos = dest->length; + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + o_addchr(&dest, (dest.o_expflags || dquoted) ? 0x80 | '`' : '`'); + if (!add_till_backquote(&dest, &input, + /*in_dquote:*/ dest.o_expflags /* nonzero if EXP_FLAG_ESC_GLOB_CHARS set */ + ) + ) { + goto ret; /* error */ + } + o_addchr(&dest, SPECIAL_VAR_SYMBOL); + //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos); + continue; + } +#endif + if (dquoted) { + /* Always glob-protect if in dquotes: + * x=x; echo "${x:+/bin/c*}" - prints: /bin/c* + * x=x; echo "${x:+"/bin/c*"}" - prints: /bin/c* + */ + o_addqchr(&dest, ch); + } else { + /* Glob-protect only if char is quoted: + * x=x; echo ${x:+/bin/c*} - prints many filenames + * x=x; echo ${x:+"/bin/c*"} - prints: /bin/c* + */ + o_addQchr(&dest, ch); + } + } /* for (;;) */ + + if (dest.data) { + n = expand_vars_to_list(output, n, dest.data); + } + ret: + o_free(&dest); + return n; +} + +#if ENABLE_FEATURE_SH_MATH +static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p) +{ + arith_state_t math_state; + arith_t res; + char *exp_str; + + math_state.lookupvar = get_local_var_value; + math_state.setvar = set_local_var_from_halves; + //math_state.endofname = endofname; + exp_str = encode_then_expand_string(arg); + res = arith(&math_state, exp_str ? exp_str : arg); + free(exp_str); + if (errmsg_p) + *errmsg_p = math_state.errmsg; + if (math_state.errmsg) + msg_and_die_if_script(math_state.errmsg); + return res; +} +#endif + +#if BASH_PATTERN_SUBST +/* ${var/[/]pattern[/repl]} helpers */ +static char *strstr_pattern(char *val, const char *pattern, int *size) +{ + int sz = strcspn(pattern, "*?[\"); + if (pattern[sz] == '\0') { + /* Optimization for trivial patterns. + * Testcase for very slow replace (performs about 22k replaces): + * x=:::::::::::::::::::::: + * x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;echo ${#x} + * echo "${x//:/|}" + */ + *size = sz; + return strstr(val, pattern); + } + + while (1) { + char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF); + debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end); + if (end) { + *size = end - val; + return val; + } + if (*val == '\0') + return NULL; + /* Optimization: if "*pat" did not match the start of "string", + * we know that "tring", "ring" etc will not match too: + */ + if (pattern[0] == '*') + return NULL; + val++; + } +} +static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op) +{ + char *result = NULL; + unsigned res_len = 0; + unsigned repl_len = strlen(repl); + + /* Null pattern never matches, including if "var" is empty */ + if (!pattern[0]) + return result; /* NULL, no replaces happened */ + + while (1) { + int size; + char *s = strstr_pattern(val, pattern, &size); + if (!s) + break; + + result = xrealloc(result, res_len + (s - val) + repl_len + 1); + strcpy(mempcpy(result + res_len, val, s - val), repl); + res_len += (s - val) + repl_len; + debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result); + + val = s + size; + if (exp_op == '/') + break; + } + if (*val && result) { + result = xrealloc(result, res_len + strlen(val) + 1); + strcpy(result + res_len, val); + debug_printf_varexp("val:'%s' result:'%s'\n", val, result); + } + debug_printf_varexp("result:'%s'\n", result); + return result; +} +#endif /* BASH_PATTERN_SUBST */ + +static int append_str_maybe_ifs_split(o_string *output, int n, + int first_ch, const char *val) +{ + if (!(first_ch & 0x80)) { /* unquoted $VAR */ + debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, + !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)); + if (val && val[0]) + n = expand_on_ifs(output, n, val); + } else { /* quoted "$VAR" */ + output->has_quoted_part = 1; + debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, + !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)); + if (val && val[0]) + o_addQstr(output, val); + } + return n; +} + +/* Handle <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct. + */ +static NOINLINE int expand_one_var(o_string *output, int n, + int first_ch, char *arg, char **pp) +{ + const char *val; + char *to_be_freed; + char *p; + char *var; + char exp_op; + char exp_save = exp_save; /* for compiler */ + char *exp_saveptr; /* points to expansion operator */ + char *exp_word = exp_word; /* for compiler */ + char arg0; + + val = NULL; + to_be_freed = NULL; + p = *pp; + *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */ + var = arg; + exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL; + arg0 = arg[0]; + arg[0] = (arg0 & 0x7f); + exp_op = 0; + + if (arg[0] == '#' && arg[1] /* ${#...} but not ${#} */ + && (!exp_saveptr /* and ( not(${#<op_char>...}) */ + || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */ + ) /* NB: skipping ^^^specvar check mishandles ${#::2} */ + ) { + /* It must be length operator: ${#var} */ + var++; + exp_op = 'L'; + } else { + /* Maybe handle parameter expansion */ + if (exp_saveptr /* if 2nd char is one of expansion operators */ + && strchr(NUMERIC_SPECVARS_STR, arg[0]) /* 1st char is special variable */ + ) { + /* ${?:0}, ${#[:]%0} etc */ + exp_saveptr = var + 1; + } else { + /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */ + exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS); + } + exp_op = exp_save = *exp_saveptr; + if (exp_op) { + exp_word = exp_saveptr + 1; + if (exp_op == ':') { + exp_op = *exp_word++; +//TODO: try ${var:} and ${var:bogus} in non-bash config + if (BASH_SUBSTR + && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op)) + ) { + /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */ + exp_op = ':'; + exp_word--; + } + } + *exp_saveptr = '\0'; + } /* else: it's not an expansion op, but bare ${var} */ + } + + /* Look up the variable in question */ + if (isdigit(var[0])) { + /* parse_dollar should have vetted var for us */ + int nn = xatoi_positive(var); + if (nn < G.global_argc) + val = G.global_argv[nn]; + /* else val remains NULL: $N with too big N */ + } else { + switch (var[0]) { + case '$': /* pid */ + val = utoa(G.root_pid); + break; + case '!': /* bg pid */ + val = G.last_bg_pid ? utoa(G.last_bg_pid) : ""; + break; + case '?': /* exitcode */ + val = utoa(G.last_exitcode); + break; + case '#': /* argc */ + val = utoa(G.global_argc ? G.global_argc-1 : 0); + break; + case '-': { /* active options */ + /* Check set_mode() to see what option chars we support */ + char *cp; + val = cp = G.optstring_buf; + if (G.o_opt[OPT_O_ERREXIT]) + *cp++ = 'e'; + if (G_interactive_fd) + *cp++ = 'i'; + if (G_x_mode) + *cp++ = 'x'; + /* If G.o_opt[OPT_O_NOEXEC] is true, + * commands read but are not executed, + * so $- can not execute too, 'n' is never seen in $-. + */ + if (G.opt_c) + *cp++ = 'c'; + if (G.opt_s) + *cp++ = 's'; + *cp = '\0'; + break; + } + default: + val = get_local_var_value(var); + } + } + + /* Handle any expansions */ + if (exp_op == 'L') { + reinit_unicode_for_hush(); + debug_printf_expand("expand: length(%s)=", val); + val = utoa(val ? unicode_strlen(val) : 0); + debug_printf_expand("%s\n", val); + } else if (exp_op) { + if (exp_op == '%' || exp_op == '#') { + /* Standard-mandated substring removal ops: + * ${parameter%word} - remove smallest suffix pattern + * ${parameter%%word} - remove largest suffix pattern + * ${parameter#word} - remove smallest prefix pattern + * ${parameter##word} - remove largest prefix pattern + * + * Word is expanded to produce a glob pattern. + * Then var's value is matched to it and matching part removed. + */ + /* bash compat: if x is "" and no shrinking of it is possible, + * inner ${...} is not evaluated. Example: + * unset b; : ${a%${b=B}}; echo $b + * assignment b=B only happens if $a is not "". + */ + if (val && val[0]) { + char *t; + char *exp_exp_word; + char *loc; + unsigned scan_flags = pick_scan(exp_op, *exp_word); + if (exp_op == *exp_word) /* ## or %% */ + exp_word++; + debug_printf_expand("expand: exp_word:'%s'\n", exp_word); + exp_exp_word = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 0); + if (exp_exp_word) + exp_word = exp_exp_word; + debug_printf_expand("expand: exp_word:'%s'\n", exp_word); + /* + * HACK ALERT. We depend here on the fact that + * G.global_argv and results of utoa and get_local_var_value + * are actually in writable memory: + * scan_and_match momentarily stores NULs there. + */ + t = (char*)val; + loc = scan_and_match(t, exp_word, scan_flags); + debug_printf_expand("op:%c str:'%s' pat:'%s' res:'%s'\n", exp_op, t, exp_word, loc); + free(exp_exp_word); + if (loc) { /* match was found */ + if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */ + val = loc; /* take right part */ + else /* %[%] */ + val = to_be_freed = xstrndup(val, loc - val); /* left */ + } + } + } +#if BASH_PATTERN_SUBST + else if (exp_op == '/' || exp_op == '\') { + /* It's ${var/[/]pattern[/repl]} thing. + * Note that in encoded form it has TWO parts: + * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL> + * and if // is used, it is encoded as : + * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL> + */ + /* bash compat: if var is "", both pattern and repl + * are still evaluated, if it is unset, then not: + * unset b; a=; : ${a/z/${b=3}}; echo $b # b=3 + * unset b; unset a; : ${a/z/${b=3}}; echo $b # b not set + */ + if (val /*&& val[0]*/) { + /* pattern uses non-standard expansion. + * repl should be unbackslashed and globbed + * by the usual expansion rules: + * >az >bz + * v='a bz'; echo "${v/a*z/a*z}" #prints "a*z" + * v='a bz'; echo "${v/a*z/\z}" #prints "z" + * v='a bz'; echo ${v/a*z/a*z} #prints "az" + * v='a bz'; echo ${v/a*z/\z} #prints "z" + * (note that a*z _pattern_ is never globbed!) + */ + char *pattern, *repl, *t; + pattern = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 0); + if (!pattern) + pattern = xstrdup(exp_word); + debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern); + *p++ = SPECIAL_VAR_SYMBOL; + exp_word = p; + p = strchr(p, SPECIAL_VAR_SYMBOL); + *p = '\0'; + repl = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 1); + debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl); + /* HACK ALERT. We depend here on the fact that + * G.global_argv and results of utoa and get_local_var_value + * are actually in writable memory: + * replace_pattern momentarily stores NULs there. */ + t = (char*)val; + to_be_freed = replace_pattern(t, + pattern, + (repl ? repl : exp_word), + exp_op); + if (to_be_freed) /* at least one replace happened */ + val = to_be_freed; + free(pattern); + free(repl); + } else { + /* Unset variable always gives nothing */ + // a=; echo ${a/*/w} # "w" + // unset a; echo ${a/*/w} # "" + /* Just skip "replace" part */ + *p++ = SPECIAL_VAR_SYMBOL; + p = strchr(p, SPECIAL_VAR_SYMBOL); + *p = '\0'; + } + } +#endif /* BASH_PATTERN_SUBST */ + else if (exp_op == ':') { +#if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH + /* It's ${var:N[:M]} bashism. + * Note that in encoded form it has TWO parts: + * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL> + */ + arith_t beg, len; + unsigned vallen; + const char *errmsg; + + beg = expand_and_evaluate_arith(exp_word, &errmsg); + if (errmsg) + goto empty_result; + debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg); + *p++ = SPECIAL_VAR_SYMBOL; + exp_word = p; + p = strchr(p, SPECIAL_VAR_SYMBOL); + *p = '\0'; + vallen = val ? strlen(val) : 0; + if (beg < 0) { + /* negative beg counts from the end */ + beg = (arith_t)vallen + beg; + } + /* If expansion will be empty, do not even evaluate len */ + if (!val || beg < 0 || beg > vallen) { + /* Why > vallen, not >=? bash: + * unset b; a=ab; : ${a:2:${b=3}}; echo $b # "", b=3 (!!!) + * unset b; a=a; : ${a:2:${b=3}}; echo $b # "", b not set + */ + goto empty_result; + } + len = expand_and_evaluate_arith(exp_word, &errmsg); + if (errmsg) + goto empty_result; + debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len); + debug_printf_varexp("from val:'%s'\n", val); + if (len < 0) { + /* in bash, len=-n means strlen()-n */ + len = (arith_t)vallen - beg + len; + if (len < 0) /* bash compat */ + msg_and_die_if_script("%s: substring expression < 0", var); + } + if (len <= 0 || !val /*|| beg >= vallen*/) { + empty_result: + val = NULL; + } else { + /* Paranoia. What if user entered 9999999999999 + * which fits in arith_t but not int? */ + if (len > INT_MAX) + len = INT_MAX; + val = to_be_freed = xstrndup(val + beg, len); + } + debug_printf_varexp("val:'%s'\n", val); +#else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */ + msg_and_die_if_script("malformed ${%s:...}", var); + val = NULL; +#endif + } else { /* one of "-=+?" */ + /* Standard-mandated substitution ops: + * ${var?word} - indicate error if unset + * If var is unset, word (or a message indicating it is unset + * if word is null) is written to standard error + * and the shell exits with a non-zero exit status. + * Otherwise, the value of var is substituted. + * ${var-word} - use default value + * If var is unset, word is substituted. + * ${var=word} - assign and use default value + * If var is unset, word is assigned to var. + * In all cases, final value of var is substituted. + * ${var+word} - use alternative value + * If var is unset, null is substituted. + * Otherwise, word is substituted. + * + * Word is subjected to tilde expansion, parameter expansion, + * command substitution, and arithmetic expansion. + * If word is not needed, it is not expanded. + * + * Colon forms (${var:-word}, ${var:=word} etc) do the same, + * but also treat null var as if it is unset. + * + * Word-splitting and single quote behavior: + * + * $ f() { for i; do echo "|$i|"; done; } + * + * $ x=; f ${x:?'x y' z}; echo $? + * bash: x: x y z # neither f nor "echo $?" executes + * (if interactive, bash does not exit, but merely aborts to prompt. $? is set to 1) + * $ x=; f "${x:?'x y' z}" + * bash: x: x y z # dash prints: dash: x: 'x y' z + * + * $ x=; f ${x:='x y' z} + * |x| + * |y| + * |z| + * $ x=; f "${x:='x y' z}" + * |'x y' z| + * + * $ x=x; f ${x:+'x y' z} + * |x y| + * |z| + * $ x=x; f "${x:+'x y' z}" + * |'x y' z| + * + * $ x=; f ${x:-'x y' z} + * |x y| + * |z| + * $ x=; f "${x:-'x y' z}" + * |'x y' z| + */ + int use_word = (!val || ((exp_save == ':') && !val[0])); + if (exp_op == '+') + use_word = !use_word; + debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op, + (exp_save == ':') ? "true" : "false", use_word); + if (use_word) { + if (exp_op == '+' || exp_op == '-') { + /* ${var+word} - use alternative value */ + /* ${var-word} - use default value */ + n = encode_then_append_var_plusminus(output, n, exp_word, + /*dquoted:*/ (arg0 & 0x80) + ); + val = NULL; + } else { + /* ${var?word} - indicate error if unset */ + /* ${var=word} - assign and use default value */ + to_be_freed = encode_then_expand_vararg(exp_word, + /*handle_squotes:*/ !(arg0 & 0x80), + /*unbackslash:*/ 0 + ); + if (to_be_freed) + exp_word = to_be_freed; + if (exp_op == '?') { + /* mimic bash message */ + msg_and_die_if_script("%s: %s", + var, + exp_word[0] + ? exp_word + : "parameter null or not set" + /* ash has more specific messages, a-la: */ + /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/ + ); +//TODO: how interactive bash aborts expansion mid-command? +//It aborts the entire line, returns to prompt: +// $ f() { for i; do echo "|$i|"; done; }; x=; f "${x:?'x y' z}"; echo YO +// bash: x: x y z +// $ +// ("echo YO" is not executed, neither the f function call) + } else { + val = exp_word; + } + if (exp_op == '=') { + /* ${var=[word]} or ${var:=[word]} */ + if (isdigit(var[0]) || var[0] == '#') { + /* mimic bash message */ + msg_and_die_if_script("$%s: cannot assign in this way", var); + val = NULL; + } else { + char *new_var = xasprintf("%s=%s", var, val); + set_local_var(new_var, /*flag:*/ 0); + } + } + } + } + } /* one of "-=+?" */ + + *exp_saveptr = exp_save; + } /* if (exp_op) */ + + arg[0] = arg0; + *pp = p; + + n = append_str_maybe_ifs_split(output, n, first_ch, val); + + free(to_be_freed); + return n; +} + +/* Expand all variable references in given string, adding words to list[] + * at n, n+1,... positions. Return updated n (so that list[n] is next one + * to be filled). This routine is extremely tricky: has to deal with + * variables/parameters with whitespace, $* and $@, and constructs like + * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ +static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg) +{ + /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in + * expansion of right-hand side of assignment == 1-element expand. + */ + char cant_be_null = 0; /* only bit 0x80 matters */ + char *p; + + debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg, + !!(output->o_expflags & EXP_FLAG_SINGLEWORD)); + debug_print_list("expand_vars_to_list[0]", output, n); + + while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) { + char first_ch; +#if ENABLE_FEATURE_SH_MATH + char arith_buf[sizeof(arith_t)*3 + 2]; +#endif + + if (output->ended_in_ifs) { + o_addchr(output, '\0'); + n = o_save_ptr(output, n); + output->ended_in_ifs = 0; + } + + o_addblock(output, arg, p - arg); + debug_print_list("expand_vars_to_list[1]", output, n); + arg = ++p; + p = strchr(p, SPECIAL_VAR_SYMBOL); + + /* Fetch special var name (if it is indeed one of them) + * and quote bit, force the bit on if singleword expansion - + * important for not getting v=$@ expand to many words. */ + first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD); + + /* Is this variable quoted and thus expansion can't be null? + * "$@" is special. Even if quoted, it can still + * expand to nothing (not even an empty string), + * thus it is excluded. */ + if ((first_ch & 0x7f) != '@') + cant_be_null |= first_ch; + + switch (first_ch & 0x7f) { + /* Highest bit in first_ch indicates that var is double-quoted */ + case '*': + case '@': { + int i; + if (!G.global_argv[1]) + break; + i = 1; + cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ + if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ + while (G.global_argv[i]) { + n = expand_on_ifs(output, n, G.global_argv[i]); + debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1); + if (G.global_argv[i++][0] && G.global_argv[i]) { + /* this argv[] is not empty and not last: + * put terminating NUL, start new word */ + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[2]", output, n); + n = o_save_ptr(output, n); + debug_print_list("expand_vars_to_list[3]", output, n); + } + } + } else + /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....' + * and in this case should treat it like '$*' - see 'else...' below */ + if (first_ch == (char)('@'|0x80) /* quoted $@ */ + && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */ + ) { + while (1) { + o_addQstr(output, G.global_argv[i]); + if (++i >= G.global_argc) + break; + o_addchr(output, '\0'); + debug_print_list("expand_vars_to_list[4]", output, n); + n = o_save_ptr(output, n); + } + } else { /* quoted $* (or v="$@" case): add as one word */ + while (1) { + o_addQstr(output, G.global_argv[i]); + if (!G.global_argv[++i]) + break; + if (G.ifs[0]) + o_addchr(output, G.ifs[0]); + } + output->has_quoted_part = 1; + } + break; + } + case SPECIAL_VAR_SYMBOL: { + /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */ + /* "Empty variable", used to make "" etc to not disappear */ + output->has_quoted_part = 1; + cant_be_null = 0x80; + arg++; + break; + } + case SPECIAL_VAR_QUOTED_SVS: + /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_QUOTED_SVS><SPECIAL_VAR_SYMBOL> */ + /* "^C variable", represents literal ^C char (possible in scripts) */ + o_addchr(output, SPECIAL_VAR_SYMBOL); + arg++; + break; +#if ENABLE_HUSH_TICK + case '`': { + /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */ + o_string subst_result = NULL_O_STRING; + + *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */ + arg++; + /* Can't just stuff it into output o_string, + * expanded result may need to be globbed + * and $IFS-split */ + debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); + G.last_exitcode = process_command_subs(&subst_result, arg); + G.expand_exitcode = G.last_exitcode; + debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data); + n = append_str_maybe_ifs_split(output, n, first_ch, subst_result.data); + o_free(&subst_result); + break; + } +#endif +#if ENABLE_FEATURE_SH_MATH + case '+': { + /* <SPECIAL_VAR_SYMBOL>+arith<SPECIAL_VAR_SYMBOL> */ + arith_t res; + + arg++; /* skip '+' */ + *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */ + debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch); + res = expand_and_evaluate_arith(arg, NULL); + debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res); + sprintf(arith_buf, ARITH_FMT, res); + if (res < 0 + && first_ch == (char)('+'|0x80) + /* && (output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS) */ + ) { + /* Quoted negative ariths, like filename[0"$((-9))"], + * should not be interpreted as glob ranges. + * Convert leading '-' to '-': + */ + o_grow_by(output, 1); + output->data[output->length++] = '\'; + } + o_addstr(output, arith_buf); + break; + } +#endif + default: + /* <SPECIAL_VAR_SYMBOL>varname[ops]<SPECIAL_VAR_SYMBOL> */ + n = expand_one_var(output, n, first_ch, arg, &p); + break; + } /* switch (char after <SPECIAL_VAR_SYMBOL>) */ + + /* Restore NULL'ed SPECIAL_VAR_SYMBOL. + * Do the check to avoid writing to a const string. */ + if (*p != SPECIAL_VAR_SYMBOL) + *p = SPECIAL_VAR_SYMBOL; + arg = ++p; + } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */ + + if (*arg) { + /* handle trailing string */ + if (output->ended_in_ifs) { + o_addchr(output, '\0'); + n = o_save_ptr(output, n); + } + debug_print_list("expand_vars_to_list[a]", output, n); + /* this part is literal, and it was already pre-quoted + * if needed (much earlier), do not use o_addQstr here! + */ + o_addstr(output, arg); + debug_print_list("expand_vars_to_list[b]", output, n); + } else + if (output->length == o_get_last_ptr(output, n) /* expansion is empty */ + && !(cant_be_null & 0x80) /* and all vars were not quoted */ + && !output->has_quoted_part + ) { + n--; + /* allow to reuse list[n] later without re-growth */ + output->has_empty_slot = 1; + } + + return n; +} + +static char **expand_variables(char **argv, unsigned expflags) +{ + int n; + char **list; + o_string output = NULL_O_STRING; + + output.o_expflags = expflags; + + n = 0; + for (;;) { + /* go to next list[n] */ + output.ended_in_ifs = 0; + n = o_save_ptr(&output, n); + + if (!*argv) + break; + + /* expand argv[i] */ + n = expand_vars_to_list(&output, n, *argv++); + /* if (!output->has_empty_slot) -- need this?? */ + o_addchr(&output, '\0'); + } + debug_print_list("expand_variables", &output, n); + + /* output.data (malloced in one block) gets returned in "list" */ + list = o_finalize_list(&output, n); + debug_print_strings("expand_variables[1]", list); + return list; +} + +static char **expand_strvec_to_strvec(char **argv) +{ + return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS); +} + +#if defined(CMD_SINGLEWORD_NOGLOB) || defined(CMD_TEST2_SINGLEWORD_NOGLOB) +static char **expand_strvec_to_strvec_singleword_noglob(char **argv) +{ + return expand_variables(argv, EXP_FLAG_SINGLEWORD); +} +#endif + +/* Used for expansion of right hand of assignments, + * $((...)), heredocs, variable expansion parts. + * + * NB: should NOT do globbing! + * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*" + */ +static char *expand_string_to_string(const char *str, int EXP_flags, int do_unbackslash) +{ +#if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE + const int do_unbackslash = 1; + const int EXP_flags = EXP_FLAG_ESC_GLOB_CHARS; +#endif + char *argv[2], **list; + + debug_printf_expand("string_to_string<='%s'\n", str); + /* This is generally an optimization, but it also + * handles "", which otherwise trips over !list[0] check below. + * (is this ever happens that we actually get str="" here?) + */ + if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\')) { + //TODO: Can use on strings with \ too, just unbackslash() them? + debug_printf_expand("string_to_string(fast)=>'%s'\n", str); + return xstrdup(str); + } + + argv[0] = (char*)str; + argv[1] = NULL; + list = expand_variables(argv, EXP_flags | EXP_FLAG_SINGLEWORD); + if (!list[0]) { + /* Example where it happens: + * x=; echo ${x:-"$@"} + */ + ((char*)list)[0] = '\0'; + } else { + if (HUSH_DEBUG) + if (list[1]) + bb_simple_error_msg_and_die("BUG in varexp2"); + /* actually, just move string 2*sizeof(char*) bytes back */ + overlapping_strcpy((char*)list, list[0]); + if (do_unbackslash) + unbackslash((char*)list); + } + debug_printf_expand("string_to_string=>'%s'\n", (char*)list); + return (char*)list; +} + +#if 0 +static char* expand_strvec_to_string(char **argv) +{ + char **list; + + list = expand_variables(argv, EXP_FLAG_SINGLEWORD); + /* Convert all NULs to spaces */ + if (list[0]) { + int n = 1; + while (list[n]) { + if (HUSH_DEBUG) + if (list[n-1] + strlen(list[n-1]) + 1 != list[n]) + bb_error_msg_and_die("BUG in varexp3"); + /* bash uses ' ' regardless of $IFS contents */ + list[n][-1] = ' '; + n++; + } + } + overlapping_strcpy((char*)list, list[0] ? list[0] : ""); + debug_printf_expand("strvec_to_string='%s'\n", (char*)list); + return (char*)list; +} +#endif + +static char **expand_assignments(char **argv, int count) +{ + int i; + char **p; + + G.expanded_assignments = p = NULL; + /* Expand assignments into one string each */ + for (i = 0; i < count; i++) { + p = add_string_to_strings(p, + expand_string_to_string(argv[i], + EXP_FLAG_ESC_GLOB_CHARS, + /*unbackslash:*/ 1 + ) + ); + G.expanded_assignments = p; + } + G.expanded_assignments = NULL; + return p; +} + + +static void switch_off_special_sigs(unsigned mask) +{ + unsigned sig = 0; + while ((mask >>= 1) != 0) { + sig++; + if (!(mask & 1)) + continue; +#if ENABLE_HUSH_TRAP + if (G_traps) { + if (G_traps[sig] && !G_traps[sig][0]) + /* trap is '', has to remain SIG_IGN */ + continue; + free(G_traps[sig]); + G_traps[sig] = NULL; + } +#endif + /* We are here only if no trap or trap was not '' */ + install_sighandler(sig, SIG_DFL); + } +} + +#if BB_MMU +/* never called */ +void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) NORETURN; + +static void reset_traps_to_defaults(void) +{ + /* This function is always called in a child shell + * after fork (not vfork, NOMMU doesn't use this function). + */ + IF_HUSH_TRAP(unsigned sig;) + unsigned mask; + + /* Child shells are not interactive. + * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling. + * Testcase: (while :; do :; done) + ^Z should background. + * Same goes for SIGTERM, SIGHUP, SIGINT. + */ + mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask; + if (!G_traps && !mask) + return; /* already no traps and no special sigs */ + + /* Switch off special sigs */ + switch_off_special_sigs(mask); +# if ENABLE_HUSH_JOB + G_fatal_sig_mask = 0; +# endif + G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS; + /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS + * remain set in G.special_sig_mask */ + +# if ENABLE_HUSH_TRAP + if (!G_traps) + return; + + /* Reset all sigs to default except ones with empty traps */ + for (sig = 0; sig < NSIG; sig++) { + if (!G_traps[sig]) + continue; /* no trap: nothing to do */ + if (!G_traps[sig][0]) + continue; /* empty trap: has to remain SIG_IGN */ + /* sig has non-empty trap, reset it: */ + free(G_traps[sig]); + G_traps[sig] = NULL; + /* There is no signal for trap 0 (EXIT) */ + if (sig == 0) + continue; + install_sighandler(sig, pick_sighandler(sig)); + } +# endif +} + +#else /* !BB_MMU */ + +static void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) NORETURN; +static void re_execute_shell(char ***to_free, const char *s, + char *g_argv0, char **g_argv, + char **builtin_argv) +{ +# define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x")) + /* delims + 2 * (number of bytes in printed hex numbers) */ + char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)]; + char *heredoc_argv[4]; + struct variable *cur; +# if ENABLE_HUSH_FUNCTIONS + struct function *funcp; +# endif + char **argv, **pp; + unsigned cnt; + unsigned long long empty_trap_mask; + + if (!g_argv0) { /* heredoc */ + argv = heredoc_argv; + argv[0] = (char *) G.argv0_for_re_execing; + argv[1] = (char *) "-<"; + argv[2] = (char *) s; + argv[3] = NULL; + pp = &argv[3]; /* used as pointer to empty environment */ + goto do_exec; + } + + cnt = 0; + pp = builtin_argv; + if (pp) while (*pp++) + cnt++; + + empty_trap_mask = 0; + if (G_traps) { + int sig; + for (sig = 1; sig < NSIG; sig++) { + if (G_traps[sig] && !G_traps[sig][0]) + empty_trap_mask |= 1LL << sig; + } + } + + sprintf(param_buf, NOMMU_HACK_FMT + , (unsigned) G.root_pid + , (unsigned) G.root_ppid + , (unsigned) G.last_bg_pid + , (unsigned) G.last_exitcode + , cnt + , empty_trap_mask + IF_HUSH_LOOPS(, G.depth_of_loop) + ); +# undef NOMMU_HACK_FMT + /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...> + * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL + */ + cnt += 6; + for (cur = G.top_var; cur; cur = cur->next) { + if (!cur->flg_export || cur->flg_read_only) + cnt += 2; + } +# if ENABLE_HUSH_FUNCTIONS + for (funcp = G.top_func; funcp; funcp = funcp->next) + cnt += 3; +# endif + pp = g_argv; + while (*pp++) + cnt++; + *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt); + *pp++ = (char *) G.argv0_for_re_execing; + *pp++ = param_buf; + for (cur = G.top_var; cur; cur = cur->next) { + if (strcmp(cur->varstr, hush_version_str) == 0) + continue; + if (cur->flg_read_only) { + *pp++ = (char *) "-R"; + *pp++ = cur->varstr; + } else if (!cur->flg_export) { + *pp++ = (char *) "-V"; + *pp++ = cur->varstr; + } + } +# if ENABLE_HUSH_FUNCTIONS + for (funcp = G.top_func; funcp; funcp = funcp->next) { + *pp++ = (char *) "-F"; + *pp++ = funcp->name; + *pp++ = funcp->body_as_string; + } +# endif + /* We can pass activated traps here. Say, -Tnn:trap_string + * + * However, POSIX says that subshells reset signals with traps + * to SIG_DFL. + * I tested bash-3.2 and it not only does that with true subshells + * of the form ( list ), but with any forked children shells. + * I set trap "echo W" WINCH; and then tried: + * + * { echo 1; sleep 20; echo 2; } & + * while true; do echo 1; sleep 20; echo 2; break; done & + * true | { echo 1; sleep 20; echo 2; } | cat + * + * In all these cases sending SIGWINCH to the child shell + * did not run the trap. If I add trap "echo V" WINCH; + * _inside_ group (just before echo 1), it works. + * + * I conclude it means we don't need to pass active traps here. + */ + *pp++ = (char *) "-c"; + *pp++ = (char *) s; + if (builtin_argv) { + while (*++builtin_argv) + *pp++ = *builtin_argv; + *pp++ = (char *) ""; + } + *pp++ = g_argv0; + while (*g_argv) + *pp++ = *g_argv++; + /* *pp = NULL; - is already there */ + pp = environ; + + do_exec: + debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s); + /* Don't propagate SIG_IGN to the child */ + if (SPECIAL_JOBSTOP_SIGS != 0) + switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS); + execve(bb_busybox_exec_path, argv, pp); + /* Fallback. Useful for init=/bin/hush usage etc */ + if (argv[0][0] == '/') + execve(argv[0], argv, pp); + xfunc_error_retval = 127; + bb_simple_error_msg_and_die("can't re-execute the shell"); +} +#endif /* !BB_MMU */ + + +static int run_and_free_list(struct pipe *pi); + +/* Executing from string: eval, sh -c '...' + * or from file: /etc/profile, . file, sh <script>, sh (intereactive) + * end_trigger controls how often we stop parsing + * NUL: parse all, execute, return + * ';': parse till ';' or newline, execute, repeat till EOF + */ +static void parse_and_run_stream(struct in_str *inp, int end_trigger) +{ + /* Why we need empty flag? + * An obscure corner case "false; ``; echo $?": + * empty command in `` should still set $? to 0. + * But we can't just set $? to 0 at the start, + * this breaks "false; echo `echo $?`" case. + */ + bool empty = 1; + while (1) { + struct pipe *pipe_list; + +#if ENABLE_HUSH_INTERACTIVE + if (end_trigger == ';') { + G.promptmode = 0; /* PS1 */ + debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode); + } +#endif + pipe_list = parse_stream(NULL, NULL, inp, end_trigger); + if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */ + /* If we are in "big" script + * (not in `cmd` or something similar)... + */ + if (pipe_list == ERR_PTR && end_trigger == ';') { + /* Discard cached input (rest of line) */ + int ch = inp->last_char; + while (ch != EOF && ch != '\n') { + //bb_error_msg("Discarded:'%c'", ch); + ch = i_getch(inp); + } + /* Force prompt */ + inp->p = NULL; + /* This stream isn't empty */ + empty = 0; + continue; + } + if (!pipe_list && empty) + G.last_exitcode = 0; + break; + } + debug_print_tree(pipe_list, 0); + debug_printf_exec("parse_and_run_stream: run_and_free_list\n"); + run_and_free_list(pipe_list); + empty = 0; + if (G_flag_return_in_progress == 1) + break; + } +} + +static void parse_and_run_string(const char *s) +{ + struct in_str input; + //IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;) + + setup_string_in_str(&input, s); + parse_and_run_stream(&input, '\0'); + //IF_HUSH_LINENO_VAR(G.parse_lineno = sv;) +} + +static void parse_and_run_file(HFILE *fp) +{ + struct in_str input; + IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;) + + IF_HUSH_LINENO_VAR(G.parse_lineno = 1;) + setup_file_in_str(&input, fp); + parse_and_run_stream(&input, ';'); + IF_HUSH_LINENO_VAR(G.parse_lineno = sv;) +} + +#if ENABLE_HUSH_TICK +static int generate_stream_from_string(const char *s, pid_t *pid_p) +{ + pid_t pid; + int channel[2]; +# if !BB_MMU + char **to_free = NULL; +# endif + + xpipe(channel); + pid = BB_MMU ? xfork() : xvfork(); + if (pid == 0) { /* child */ + disable_restore_tty_pgrp_on_exit(); + /* Process substitution is not considered to be usual + * 'command execution'. + * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. + */ + bb_signals(0 + + (1 << SIGTSTP) + + (1 << SIGTTIN) + + (1 << SIGTTOU) + , SIG_IGN); + close(channel[0]); /* NB: close _first_, then move fd! */ + xmove_fd(channel[1], 1); +# if ENABLE_HUSH_TRAP + /* Awful hack for `trap` or $(trap). + * + * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html + * contains an example where "trap" is executed in a subshell: + * + * save_traps=$(trap) + * ... + * eval "$save_traps" + * + * Standard does not say that "trap" in subshell shall print + * parent shell's traps. It only says that its output + * must have suitable form, but then, in the above example + * (which is not supposed to be normative), it implies that. + * + * bash (and probably other shell) does implement it + * (traps are reset to defaults, but "trap" still shows them), + * but as a result, "trap" logic is hopelessly messed up: + * + * # trap + * trap -- 'echo Ho' SIGWINCH <--- we have a handler + * # (trap) <--- trap is in subshell - no output (correct, traps are reset) + * # true | trap <--- trap is in subshell - no output (ditto) + * # echo `true | trap` <--- in subshell - output (but traps are reset!) + * trap -- 'echo Ho' SIGWINCH + * # echo `(trap)` <--- in subshell in subshell - output + * trap -- 'echo Ho' SIGWINCH + * # echo `true | (trap)` <--- in subshell in subshell in subshell - output! + * trap -- 'echo Ho' SIGWINCH + * + * The rules when to forget and when to not forget traps + * get really complex and nonsensical. + * + * Our solution: ONLY bare $(trap) or `trap` is special. + */ + s = skip_whitespace(s); + if (is_prefixed_with(s, "trap") + && skip_whitespace(s + 4)[0] == '\0' + ) { + static const char *const argv[] = { NULL, NULL }; + builtin_trap((char**)argv); + fflush_all(); /* important */ + _exit(0); + } +# endif +# if BB_MMU + /* Prevent it from trying to handle ctrl-z etc */ + IF_HUSH_JOB(G.run_list_level = 1;) + CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */ + reset_traps_to_defaults(); + IF_HUSH_MODE_X(G.x_mode_depth++;) + //bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth); + parse_and_run_string(s); + _exit(G.last_exitcode); +# else + /* We re-execute after vfork on NOMMU. This makes this script safe: + * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG + * huge=`cat BIG` # was blocking here forever + * echo OK + */ + re_execute_shell(&to_free, + s, + G.global_argv[0], + G.global_argv + 1, + NULL); +# endif + } + + /* parent */ + *pid_p = pid; +# if ENABLE_HUSH_FAST + G.count_SIGCHLD++; +//bb_error_msg("[%d] fork in generate_stream_from_string:" +// " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", +// getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); +# endif + enable_restore_tty_pgrp_on_exit(); +# if !BB_MMU + free(to_free); +# endif + close(channel[1]); + return channel[0]; +} + +/* Return code is exit status of the process that is run. */ +static int process_command_subs(o_string *dest, const char *s) +{ + FILE *fp; + pid_t pid; + int status, ch, eol_cnt; + + fp = xfdopen_for_read(generate_stream_from_string(s, &pid)); + + /* Now send results of command back into original context */ + eol_cnt = 0; + while ((ch = getc(fp)) != EOF) { + if (ch == '\0') + continue; + if (ch == '\n') { + eol_cnt++; + continue; + } + while (eol_cnt) { + o_addchr(dest, '\n'); + eol_cnt--; + } + o_addQchr(dest, ch); + } + + debug_printf("done reading from `cmd` pipe, closing it\n"); + fclose(fp); + /* We need to extract exitcode. Test case + * "true; echo `sleep 1; false` $?" + * should print 1 */ + safe_waitpid(pid, &status, 0); + debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status)); + return WEXITSTATUS(status); +} +#endif /* ENABLE_HUSH_TICK */ + + +static void setup_heredoc(struct redir_struct *redir) +{ + struct fd_pair pair; + pid_t pid; + int len, written; + /* the _body_ of heredoc (misleading field name) */ + const char *heredoc = redir->rd_filename; + char *expanded; +#if !BB_MMU + char **to_free; +#endif + + expanded = NULL; + if (!(redir->rd_dup & HEREDOC_QUOTED)) { + expanded = encode_then_expand_string(heredoc); + if (expanded) + heredoc = expanded; + } + len = strlen(heredoc); + + close(redir->rd_fd); /* often saves dup2+close in xmove_fd */ + xpiped_pair(pair); + xmove_fd(pair.rd, redir->rd_fd); + + /* Try writing without forking. Newer kernels have + * dynamically growing pipes. Must use non-blocking write! */ + ndelay_on(pair.wr); + while (1) { + written = write(pair.wr, heredoc, len); + if (written <= 0) + break; + len -= written; + if (len == 0) { + close(pair.wr); + free(expanded); + return; + } + heredoc += written; + } + ndelay_off(pair.wr); + + /* Okay, pipe buffer was not big enough */ + /* Note: we must not create a stray child (bastard? :) + * for the unsuspecting parent process. Child creates a grandchild + * and exits before parent execs the process which consumes heredoc + * (that exec happens after we return from this function) */ +#if !BB_MMU + to_free = NULL; +#endif + pid = xvfork(); + if (pid == 0) { + /* child */ + disable_restore_tty_pgrp_on_exit(); + pid = BB_MMU ? xfork() : xvfork(); + if (pid != 0) + _exit(0); + /* grandchild */ + close(redir->rd_fd); /* read side of the pipe */ +#if BB_MMU + full_write(pair.wr, heredoc, len); /* may loop or block */ + _exit(0); +#else + /* Delegate blocking writes to another process */ + xmove_fd(pair.wr, STDOUT_FILENO); + re_execute_shell(&to_free, heredoc, NULL, NULL, NULL); +#endif + } + /* parent */ +#if ENABLE_HUSH_FAST + G.count_SIGCHLD++; +//bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); +#endif + enable_restore_tty_pgrp_on_exit(); +#if !BB_MMU + free(to_free); +#endif + close(pair.wr); + free(expanded); + wait(NULL); /* wait till child has died */ +} + +struct squirrel { + int orig_fd; + int moved_to; + /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */ + /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */ +}; + +static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved) +{ + sq = xrealloc(sq, (i + 2) * sizeof(sq[0])); + sq[i].orig_fd = orig; + sq[i].moved_to = moved; + sq[i+1].orig_fd = -1; /* end marker */ + return sq; +} + +static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd) +{ + int moved_to; + int i; + + i = 0; + if (sq) for (; sq[i].orig_fd >= 0; i++) { + /* If we collide with an already moved fd... */ + if (fd == sq[i].moved_to) { + sq[i].moved_to = dup_CLOEXEC(sq[i].moved_to, avoid_fd); + debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to); + if (sq[i].moved_to < 0) /* what? */ + xfunc_die(); + return sq; + } + if (fd == sq[i].orig_fd) { + /* Example: echo Hello >/dev/null 1>&2 */ + debug_printf_redir("redirect_fd %d: already moved\n", fd); + return sq; + } + } + + /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */ + moved_to = dup_CLOEXEC(fd, avoid_fd); + debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to); + if (moved_to < 0 && errno != EBADF) + xfunc_die(); + return append_squirrel(sq, i, fd, moved_to); +} + +static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd) +{ + int i; + + i = 0; + if (sq) for (; sq[i].orig_fd >= 0; i++) { + /* If we collide with an already moved fd... */ + if (fd == sq[i].orig_fd) { + /* Examples: + * "echo 3>FILE 3>&- 3>FILE" + * "echo 3>&- 3>FILE" + * No need for last redirect to insert + * another "need to close 3" indicator. + */ + debug_printf_redir("redirect_fd %d: already moved or closed\n", fd); + return sq; + } + } + + debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd); + return append_squirrel(sq, i, fd, -1); +} + +/* fd: redirect wants this fd to be used (e.g. 3>file). + * Move all conflicting internally used fds, + * and remember them so that we can restore them later. + */ +static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp) +{ + if (avoid_fd < 9) /* the important case here is that it can be -1 */ + avoid_fd = 9; + +#if ENABLE_HUSH_INTERACTIVE + if (fd != 0 /* don't trigger for G_interactive_fd == 0 (that's "not interactive" flag) */ + && fd == G_interactive_fd + ) { + /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */ + G_interactive_fd = xdup_CLOEXEC_and_close(G_interactive_fd, avoid_fd); + debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G_interactive_fd); + return 1; /* "we closed fd" */ + } +#endif + /* Are we called from setup_redirects(squirrel==NULL) + * in redirect in a [v]forked child? + */ + if (sqp == NULL) { + /* No need to move script fds. + * For NOMMU case, it's actively wrong: we'd change ->fd + * fields in memory for the parent, but parent's fds + * aren't moved, it would use wrong fd! + * Reproducer: "cmd 3>FILE" in script. + * If we would call move_HFILEs_on_redirect(), child would: + * fcntl64(3, F_DUPFD_CLOEXEC, 10) = 10 + * close(3) = 0 + * and change ->fd to 10 if fd#3 is a script fd. WRONG. + */ + //bb_error_msg("sqp == NULL: [v]forked child"); + return 0; + } + + /* If this one of script's fds? */ + if (move_HFILEs_on_redirect(fd, avoid_fd)) + return 1; /* yes. "we closed fd" (actually moved it) */ + + /* Are we called for "exec 3>FILE"? Came through + * redirect_and_varexp_helper(squirrel=ERR_PTR) -> setup_redirects(ERR_PTR) + * This case used to fail for this script: + * exec 3>FILE + * echo Ok + * ...100000 more lines... + * echo Ok + * as follows: + * read(3, "exec 3>FILE\necho Ok\necho Ok"..., 1024) = 1024 + * open("FILE", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = 4 + * dup2(4, 3) = 3 + * ^^^^^^^^ oops, we lost fd#3 opened to our script! + * close(4) = 0 + * write(1, "Ok\n", 3) = 3 + * ... = 3 + * write(1, "Ok\n", 3) = 3 + * read(3, 0x94fbc08, 1024) = -1 EBADF (Bad file descriptor) + * ^^^^^^^^ oops, wrong fd!!! + * With this case separate from sqp == NULL and *after* move_HFILEs, + * it now works: + */ + if (sqp == ERR_PTR) { + /* Don't preserve redirected fds: exec is _meant_ to change these */ + //bb_error_msg("sqp == ERR_PTR: exec >FILE"); + return 0; + } + + /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */ + *sqp = add_squirrel(*sqp, fd, avoid_fd); + return 0; /* "we did not close fd" */ +} + +static void restore_redirects(struct squirrel *sq) +{ + if (sq) { + int i; + for (i = 0; sq[i].orig_fd >= 0; i++) { + if (sq[i].moved_to >= 0) { + /* We simply die on error */ + debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd); + xmove_fd(sq[i].moved_to, sq[i].orig_fd); + } else { + /* cmd1 9>FILE; cmd2_should_see_fd9_closed */ + debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd); + close(sq[i].orig_fd); + } + } + free(sq); + } + if (G.HFILE_stdin + && G.HFILE_stdin->fd > STDIN_FILENO + /* we compare > STDIN, not == STDIN, since hfgetc() + * closes fd and sets ->fd to -1 if EOF is reached. + * Testcase: echo 'pwd' | hush + */ + ) { + /* Testcase: interactive "read r <FILE; echo $r; read r; echo $r". + * Redirect moves ->fd to e.g. 10, + * and it is not restored above (we do not restore script fds + * after redirects, we just use new, "moved" fds). + * However for stdin, get_user_input() -> read_line_input(), + * and read builtin, depend on fd == STDIN_FILENO. + */ + debug_printf_redir("restoring %d to stdin\n", G.HFILE_stdin->fd); + xmove_fd(G.HFILE_stdin->fd, STDIN_FILENO); + G.HFILE_stdin->fd = STDIN_FILENO; + } + + /* If moved, G_interactive_fd stays on new fd, not restoring it */ +} + +#if ENABLE_FEATURE_SH_STANDALONE && BB_MMU +static void close_saved_fds_and_FILE_fds(void) +{ + if (G_interactive_fd) + close(G_interactive_fd); + close_all_HFILE_list(); +} +#endif + +static int internally_opened_fd(int fd, struct squirrel *sq) +{ + int i; + +#if ENABLE_HUSH_INTERACTIVE + if (fd == G_interactive_fd) + return 1; +#endif + /* If this one of script's fds? */ + if (fd_in_HFILEs(fd)) + return 1; + + if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) { + if (fd == sq[i].moved_to) + return 1; + } + return 0; +} + +/* squirrel != NULL means we squirrel away copies of stdin, stdout, + * and stderr if they are redirected. */ +static int setup_redirects(struct command *prog, struct squirrel **sqp) +{ + struct redir_struct *redir; + + for (redir = prog->redirects; redir; redir = redir->next) { + int newfd; + int closed; + + if (redir->rd_type == REDIRECT_HEREDOC2) { + /* "rd_fd<<HERE" case */ + save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp); + /* for REDIRECT_HEREDOC2, rd_filename holds _contents_ + * of the heredoc */ + debug_printf_redir("set heredoc '%s'\n", + redir->rd_filename); + setup_heredoc(redir); + continue; + } + + if (redir->rd_dup == REDIRFD_TO_FILE) { + /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */ + char *p; + int mode; + + if (redir->rd_filename == NULL) { + /* Examples: + * "cmd >" (no filename) + * "cmd > <file" (2nd redirect starts too early) + */ + syntax_error("invalid redirect"); + continue; + } + mode = redir_table[redir->rd_type].mode; + p = expand_string_to_string(redir->rd_filename, + EXP_FLAG_ESC_GLOB_CHARS, /*unbackslash:*/ 1); + newfd = open_or_warn(p, mode); + free(p); + if (newfd < 0) { + /* Error message from open_or_warn can be lost + * if stderr has been redirected, but bash + * and ash both lose it as well + * (though zsh doesn't!) + */ + return 1; + } + if (newfd == redir->rd_fd && sqp) { + /* open() gave us precisely the fd we wanted. + * This means that this fd was not busy + * (not opened to anywhere). + * Remember to close it on restore: + */ + *sqp = add_squirrel_closed(*sqp, newfd); + debug_printf_redir("redir to previously closed fd %d\n", newfd); + } + } else { + /* "rd_fd>&rd_dup" or "rd_fd>&-" case */ + newfd = redir->rd_dup; + } + + if (newfd == redir->rd_fd) + continue; + + /* if "N>FILE": move newfd to redir->rd_fd */ + /* if "N>&M": dup newfd to redir->rd_fd */ + /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */ + + closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp); + if (newfd == REDIRFD_CLOSE) { + /* "N>&-" means "close me" */ + if (!closed) { + /* ^^^ optimization: saving may already + * have closed it. If not... */ + close(redir->rd_fd); + } + /* Sometimes we do another close on restore, getting EBADF. + * Consider "echo 3>FILE 3>&-" + * first redirect remembers "need to close 3", + * and second redirect closes 3! Restore code then closes 3 again. + */ + } else { + /* if newfd is a script fd or saved fd, simulate EBADF */ + if (internally_opened_fd(newfd, sqp && sqp != ERR_PTR ? *sqp : NULL)) { + //errno = EBADF; + //bb_perror_msg_and_die("can't duplicate file descriptor"); + newfd = -1; /* same effect as code above */ + } + xdup2(newfd, redir->rd_fd); + if (redir->rd_dup == REDIRFD_TO_FILE) + /* "rd_fd > FILE" */ + close(newfd); + /* else: "rd_fd > rd_dup" */ + } + } + return 0; +} + +static char *find_in_path(const char *arg) +{ + char *ret = NULL; + const char *PATH = get_local_var_value("PATH"); + + if (!PATH) + return NULL; + + while (1) { + const char *end = strchrnul(PATH, ':'); + int sz = end - PATH; /* must be int! */ + + free(ret); + if (sz != 0) { + ret = xasprintf("%.*s/%s", sz, PATH, arg); + } else { + /* We have xxx::yyyy in $PATH, + * it means "use current dir" */ + ret = xstrdup(arg); + } + if (access(ret, F_OK) == 0) + break; + + if (*end == '\0') { + free(ret); + return NULL; + } + PATH = end + 1; + } + + return ret; +} + +static const struct built_in_command *find_builtin_helper(const char *name, + const struct built_in_command *x, + const struct built_in_command *end) +{ + while (x != end) { + if (strcmp(name, x->b_cmd) != 0) { + x++; + continue; + } + debug_printf_exec("found builtin '%s'\n", name); + return x; + } + return NULL; +} +static const struct built_in_command *find_builtin1(const char *name) +{ + return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]); +} +static const struct built_in_command *find_builtin(const char *name) +{ + const struct built_in_command *x = find_builtin1(name); + if (x) + return x; + return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]); +} + +#if ENABLE_HUSH_JOB && EDITING_HAS_get_exe_name +static const char * FAST_FUNC get_builtin_name(int i) +{ + if (/*i >= 0 && */ i < ARRAY_SIZE(bltins1)) { + return bltins1[i].b_cmd; + } + i -= ARRAY_SIZE(bltins1); + if (i < ARRAY_SIZE(bltins2)) { + return bltins2[i].b_cmd; + } + return NULL; +} +#endif + +static void remove_nested_vars(void) +{ + struct variable *cur; + struct variable **cur_pp; + + cur_pp = &G.top_var; + while ((cur = *cur_pp) != NULL) { + if (cur->var_nest_level <= G.var_nest_level) { + cur_pp = &cur->next; + continue; + } + /* Unexport */ + if (cur->flg_export) { + debug_printf_env("unexporting nested '%s'/%u\n", cur->varstr, cur->var_nest_level); + bb_unsetenv(cur->varstr); + } + /* Remove from global list */ + *cur_pp = cur->next; + /* Free */ + if (!cur->max_len) { + debug_printf_env("freeing nested '%s'/%u\n", cur->varstr, cur->var_nest_level); + free(cur->varstr); + } + free(cur); + } +} + +static void enter_var_nest_level(void) +{ + G.var_nest_level++; + debug_printf_env("var_nest_level++ %u\n", G.var_nest_level); + + /* Try: f() { echo -n .; f; }; f + * struct variable::var_nest_level is uint16_t, + * thus limiting recursion to < 2^16. + * In any case, with 8 Mbyte stack SEGV happens + * not too long after 2^16 recursions anyway. + */ + if (G.var_nest_level > 0xff00) + bb_error_msg_and_die("fatal recursion (depth %u)", G.var_nest_level); +} + +static void leave_var_nest_level(void) +{ + G.var_nest_level--; + debug_printf_env("var_nest_level-- %u\n", G.var_nest_level); + if (HUSH_DEBUG && (int)G.var_nest_level < 0) + bb_simple_error_msg_and_die("BUG: nesting underflow"); + + remove_nested_vars(); +} + +#if ENABLE_HUSH_FUNCTIONS +static struct function **find_function_slot(const char *name) +{ + struct function *funcp; + struct function **funcpp = &G.top_func; + + while ((funcp = *funcpp) != NULL) { + if (strcmp(name, funcp->name) == 0) { + debug_printf_exec("found function '%s'\n", name); + break; + } + funcpp = &funcp->next; + } + return funcpp; +} + +static ALWAYS_INLINE const struct function *find_function(const char *name) +{ + const struct function *funcp = *find_function_slot(name); + return funcp; +} + +/* Note: takes ownership on name ptr */ +static struct function *new_function(char *name) +{ + struct function **funcpp = find_function_slot(name); + struct function *funcp = *funcpp; + + if (funcp != NULL) { + struct command *cmd = funcp->parent_cmd; + debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd); + if (!cmd) { + debug_printf_exec("freeing & replacing function '%s'\n", funcp->name); + free(funcp->name); + /* Note: if !funcp->body, do not free body_as_string! + * This is a special case of "-F name body" function: + * body_as_string was not malloced! */ + if (funcp->body) { + free_pipe_list(funcp->body); +# if !BB_MMU + free(funcp->body_as_string); +# endif + } + } else { + debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name); + cmd->argv[0] = funcp->name; + cmd->group = funcp->body; +# if !BB_MMU + cmd->group_as_string = funcp->body_as_string; +# endif + } + } else { + debug_printf_exec("remembering new function '%s'\n", name); + funcp = *funcpp = xzalloc(sizeof(*funcp)); + /*funcp->next = NULL;*/ + } + + funcp->name = name; + return funcp; +} + +# if ENABLE_HUSH_UNSET +static void unset_func(const char *name) +{ + struct function **funcpp = find_function_slot(name); + struct function *funcp = *funcpp; + + if (funcp != NULL) { + debug_printf_exec("freeing function '%s'\n", funcp->name); + *funcpp = funcp->next; + /* funcp is unlinked now, deleting it. + * Note: if !funcp->body, the function was created by + * "-F name body", do not free ->body_as_string + * and ->name as they were not malloced. */ + if (funcp->body) { + free_pipe_list(funcp->body); + free(funcp->name); +# if !BB_MMU + free(funcp->body_as_string); +# endif + } + free(funcp); + } +} +# endif + +# if BB_MMU +#define exec_function(to_free, funcp, argv) \ + exec_function(funcp, argv) +# endif +static void exec_function(char ***to_free, + const struct function *funcp, + char **argv) NORETURN; +static void exec_function(char ***to_free, + const struct function *funcp, + char **argv) +{ +# if BB_MMU + int n; + + argv[0] = G.global_argv[0]; + G.global_argv = argv; + G.global_argc = n = 1 + string_array_len(argv + 1); + +// Example when we are here: "cmd | func" +// func will run with saved-redirect fds open. +// $ f() { echo /proc/self/fd/*; } +// $ true | f +// /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 +// stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob +// Same in script: +// $ . ./SCRIPT +// /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4 +// stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob +// They are CLOEXEC so external programs won't see them, but +// for "more correctness" we might want to close those extra fds here: +//? close_saved_fds_and_FILE_fds(); + + /* "we are in a function, ok to use return" */ + G_flag_return_in_progress = -1; + enter_var_nest_level(); + IF_HUSH_LOCAL(G.func_nest_level++;) + + /* On MMU, funcp->body is always non-NULL */ + n = run_list(funcp->body); + _exit(n); +# else +//? close_saved_fds_and_FILE_fds(); + +//TODO: check whether "true | func_with_return" works + + re_execute_shell(to_free, + funcp->body_as_string, + G.global_argv[0], + argv + 1, + NULL); +# endif +} + +static int run_function(const struct function *funcp, char **argv) +{ + int rc; + save_arg_t sv; + smallint sv_flg; + + save_and_replace_G_args(&sv, argv); + + /* "We are in function, ok to use return" */ + sv_flg = G_flag_return_in_progress; + G_flag_return_in_progress = -1; + + /* Make "local" variables properly shadow previous ones */ + IF_HUSH_LOCAL(enter_var_nest_level();) + IF_HUSH_LOCAL(G.func_nest_level++;) + + /* On MMU, funcp->body is always non-NULL */ +# if !BB_MMU + if (!funcp->body) { + /* Function defined by -F */ + parse_and_run_string(funcp->body_as_string); + rc = G.last_exitcode; + } else +# endif + { + rc = run_list(funcp->body); + } + + IF_HUSH_LOCAL(G.func_nest_level--;) + IF_HUSH_LOCAL(leave_var_nest_level();) + + G_flag_return_in_progress = sv_flg; +# if ENABLE_HUSH_TRAP + debug_printf_exec("G.return_exitcode=-1\n"); + G.return_exitcode = -1; /* invalidate stashed return value */ +# endif + + restore_G_args(&sv, argv); + + return rc; +} +#endif /* ENABLE_HUSH_FUNCTIONS */ + + +#if BB_MMU +#define exec_builtin(to_free, x, argv) \ + exec_builtin(x, argv) +#else +#define exec_builtin(to_free, x, argv) \ + exec_builtin(to_free, argv) +#endif +static void exec_builtin(char ***to_free, + const struct built_in_command *x, + char **argv) NORETURN; +static void exec_builtin(char ***to_free, + const struct built_in_command *x, + char **argv) +{ +#if BB_MMU + int rcode; +//? close_saved_fds_and_FILE_fds(); + rcode = x->b_function(argv); + fflush_all(); + _exit(rcode); +#else + fflush_all(); + /* On NOMMU, we must never block! + * Example: { sleep 99 | read line; } & echo Ok + */ + re_execute_shell(to_free, + argv[0], + G.global_argv[0], + G.global_argv + 1, + argv); +#endif +} + + +static void execvp_or_die(char **argv) NORETURN; +static void execvp_or_die(char **argv) +{ + int e; + debug_printf_exec("execing '%s'\n", argv[0]); + /* Don't propagate SIG_IGN to the child */ + if (SPECIAL_JOBSTOP_SIGS != 0) + switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS); + execvp(argv[0], argv); + e = 2; + if (errno == EACCES) e = 126; + if (errno == ENOENT) e = 127; + bb_perror_msg("can't execute '%s'", argv[0]); + _exit(e); +} + +#if ENABLE_HUSH_MODE_X +static void x_mode_print_optionally_squoted(const char *str) +{ + unsigned len; + const char *cp; + + cp = str; + + /* the set of chars which-cause-string-to-be-squoted mimics bash */ + /* test a char with: bash -c 'set -x; echo "CH"' */ + if (str[strcspn(str, "\"'`$(){}[]<>;#&|~*?!^" + " " "\001\002\003\004\005\006\007" + "\010\011\012\013\014\015\016\017" + "\020\021\022\023\024\025\026\027" + "\030\031\032\033\034\035\036\037" + ) + ] == '\0' + ) { + /* string has no special chars */ + x_mode_addstr(str); + return; + } + + cp = str; + for (;;) { + /* print '....' up to EOL or first squote */ + len = (int)(strchrnul(cp, ''') - cp); + if (len != 0) { + x_mode_addchr('''); + x_mode_addblock(cp, len); + x_mode_addchr('''); + cp += len; + } + if (*cp == '\0') + break; + /* string contains squote(s), print them as ' */ + x_mode_addchr('\'); + x_mode_addchr('''); + cp++; + } +} +static void dump_cmd_in_x_mode(char **argv) +{ + if (G_x_mode && argv) { + unsigned n; + + /* "+[+++...][ cmd...]\n\0" */ + x_mode_prefix(); + n = 0; + while (argv[n]) { + x_mode_addchr(' '); + if (argv[n][0] == '\0') { + x_mode_addchr('''); + x_mode_addchr('''); + } else { + x_mode_print_optionally_squoted(argv[n]); + } + n++; + } + x_mode_flush(); + } +} +#else +# define dump_cmd_in_x_mode(argv) ((void)0) +#endif + +#if ENABLE_HUSH_COMMAND +static void if_command_vV_print_and_exit(char opt_vV, char *cmd, const char *explanation) +{ + char *to_free; + + if (!opt_vV) + return; + + to_free = NULL; + if (!explanation) { + char *path = getenv("PATH"); + explanation = to_free = find_executable(cmd, &path); /* path == NULL is ok */ + if (!explanation) + _exit(1); /* PROG was not found */ + if (opt_vV != 'V') + cmd = to_free; /* -v PROG prints "/path/to/PROG" */ + } + printf((opt_vV == 'V') ? "%s is %s\n" : "%s\n", cmd, explanation); + free(to_free); + fflush_all(); + _exit(0); +} +#else +# define if_command_vV_print_and_exit(a,b,c) ((void)0) +#endif + +#if BB_MMU +#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \ + pseudo_exec_argv(argv, assignment_cnt, argv_expanded) +#define pseudo_exec(nommu_save, command, argv_expanded) \ + pseudo_exec(command, argv_expanded) +#endif + +/* Called after [v]fork() in run_pipe, or from builtin_exec. + * Never returns. + * Don't exit() here. If you don't exec, use _exit instead. + * The at_exit handlers apparently confuse the calling process, + * in particular stdin handling. Not sure why? -- because of vfork! (vda) + */ +static void pseudo_exec_argv(nommu_save_t *nommu_save, + char **argv, int assignment_cnt, + char **argv_expanded) NORETURN; +static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save, + char **argv, int assignment_cnt, + char **argv_expanded) +{ + const struct built_in_command *x; + struct variable **sv_shadowed; + char **new_env; + IF_HUSH_COMMAND(char opt_vV = 0;) + IF_HUSH_FUNCTIONS(const struct function *funcp;) + + new_env = expand_assignments(argv, assignment_cnt); + dump_cmd_in_x_mode(new_env); + + if (!argv[assignment_cnt]) { + /* Case when we are here: ... | var=val | ... + * (note that we do not exit early, i.e., do not optimize out + * expand_assignments(): think about ... | var=`sleep 1` | ... + */ + free_strings(new_env); + _exit(EXIT_SUCCESS); + } + + sv_shadowed = G.shadowed_vars_pp; +#if BB_MMU + G.shadowed_vars_pp = NULL; /* "don't save, free them instead" */ +#else + G.shadowed_vars_pp = &nommu_save->old_vars; + G.var_nest_level++; +#endif + set_vars_and_save_old(new_env); + G.shadowed_vars_pp = sv_shadowed; + + if (argv_expanded) { + argv = argv_expanded; + } else { + argv = expand_strvec_to_strvec(argv + assignment_cnt); +#if !BB_MMU + nommu_save->argv = argv; +#endif + } + dump_cmd_in_x_mode(argv); + +#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU + if (strchr(argv[0], '/') != NULL) + goto skip; +#endif + +#if ENABLE_HUSH_FUNCTIONS + /* Check if the command matches any functions (this goes before bltins) */ + funcp = find_function(argv[0]); + if (funcp) + exec_function(&nommu_save->argv_from_re_execing, funcp, argv); +#endif + +#if ENABLE_HUSH_COMMAND + /* "command BAR": run BAR without looking it up among functions + * "command -v BAR": print "BAR" or "/path/to/BAR"; or exit 1 + * "command -V BAR": print "BAR is {a function,a shell builtin,/path/to/BAR}" + */ + while (strcmp(argv[0], "command") == 0 && argv[1]) { + char *p; + + argv++; + p = *argv; + if (p[0] != '-' || !p[1]) + continue; /* bash allows "command command command [-OPT] BAR" */ + + for (;;) { + p++; + switch (*p) { + case '\0': + argv++; + p = *argv; + if (p[0] != '-' || !p[1]) + goto after_opts; + continue; /* next arg is also -opts, process it too */ + case 'v': + case 'V': + opt_vV = *p; + continue; + default: + bb_error_msg_and_die("%s: %s: invalid option", "command", argv[0]); + } + } + } + after_opts: +# if ENABLE_HUSH_FUNCTIONS + if (opt_vV && find_function(argv[0])) + if_command_vV_print_and_exit(opt_vV, argv[0], "a function"); +# endif +#endif + + /* Check if the command matches any of the builtins. + * Depending on context, this might be redundant. But it's + * easier to waste a few CPU cycles than it is to figure out + * if this is one of those cases. + */ + /* Why "BB_MMU ? :" difference in logic? - + * On NOMMU, it is more expensive to re-execute shell + * just in order to run echo or test builtin. + * It's better to skip it here and run corresponding + * non-builtin later. */ + x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]); + if (x) { + if_command_vV_print_and_exit(opt_vV, argv[0], "a shell builtin"); + exec_builtin(&nommu_save->argv_from_re_execing, x, argv); + } + +#if ENABLE_FEATURE_SH_STANDALONE + /* Check if the command matches any busybox applets */ + { + int a = find_applet_by_name(argv[0]); + if (a >= 0) { + if_command_vV_print_and_exit(opt_vV, argv[0], "an applet"); +# if BB_MMU /* see above why on NOMMU it is not allowed */ + if (APPLET_IS_NOEXEC(a)) { + /* Do not leak open fds from opened script files etc. + * Testcase: interactive "ls -l /proc/self/fd" + * should not show tty fd open. + */ + close_saved_fds_and_FILE_fds(); +//FIXME: should also close saved redir fds +//This casuses test failures in +//redir_children_should_not_see_saved_fd_2.tests +//redir_children_should_not_see_saved_fd_3.tests +//if you replace "busybox find" with just "find" in them + /* Without this, "rm -i FILE" can't be ^C'ed: */ + switch_off_special_sigs(G.special_sig_mask); + debug_printf_exec("running applet '%s'\n", argv[0]); + run_noexec_applet_and_exit(a, argv[0], argv); + } +# endif + /* Re-exec ourselves */ + debug_printf_exec("re-execing applet '%s'\n", argv[0]); + /* Don't propagate SIG_IGN to the child */ + if (SPECIAL_JOBSTOP_SIGS != 0) + switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS); + execv(bb_busybox_exec_path, argv); + /* If they called chroot or otherwise made the binary no longer + * executable, fall through */ + } + } +#endif + +#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU + skip: +#endif + if_command_vV_print_and_exit(opt_vV, argv[0], NULL); + execvp_or_die(argv); +} + +/* Called after [v]fork() in run_pipe + */ +static void pseudo_exec(nommu_save_t *nommu_save, + struct command *command, + char **argv_expanded) NORETURN; +static void pseudo_exec(nommu_save_t *nommu_save, + struct command *command, + char **argv_expanded) +{ +#if ENABLE_HUSH_FUNCTIONS + if (command->cmd_type == CMD_FUNCDEF) { + /* Ignore funcdefs in pipes: + * true | f() { cmd } + */ + _exit(0); + } +#endif + + if (command->argv) { + pseudo_exec_argv(nommu_save, command->argv, + command->assignment_cnt, argv_expanded); + } + + if (command->group) { + /* Cases when we are here: + * ( list ) + * { list } & + * ... | ( list ) | ... + * ... | { list } | ... + */ +#if BB_MMU + int rcode; + debug_printf_exec("pseudo_exec: run_list\n"); + reset_traps_to_defaults(); + rcode = run_list(command->group); + /* OK to leak memory by not calling free_pipe_list, + * since this process is about to exit */ + _exit(rcode); +#else + re_execute_shell(&nommu_save->argv_from_re_execing, + command->group_as_string, + G.global_argv[0], + G.global_argv + 1, + NULL); +#endif + } + + /* Case when we are here: ... | >file */ + debug_printf_exec("pseudo_exec'ed null command\n"); + _exit(EXIT_SUCCESS); +} + +#if ENABLE_HUSH_JOB +static const char *get_cmdtext(struct pipe *pi) +{ + char **argv; + char *p; + int len; + + /* This is subtle. ->cmdtext is created only on first backgrounding. + * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...) + * On subsequent bg argv is trashed, but we won't use it */ + if (pi->cmdtext) + return pi->cmdtext; + + argv = pi->cmds[0].argv; + if (!argv) { + pi->cmdtext = xzalloc(1); + return pi->cmdtext; + } + len = 0; + do { + len += strlen(*argv) + 1; + } while (*++argv); + p = xmalloc(len); + pi->cmdtext = p; + argv = pi->cmds[0].argv; + do { + p = stpcpy(p, *argv); + *p++ = ' '; + } while (*++argv); + p[-1] = '\0'; + return pi->cmdtext; +} + +static void remove_job_from_table(struct pipe *pi) +{ + struct pipe *prev_pipe; + + if (pi == G.job_list) { + G.job_list = pi->next; + } else { + prev_pipe = G.job_list; + while (prev_pipe->next != pi) + prev_pipe = prev_pipe->next; + prev_pipe->next = pi->next; + } + G.last_jobid = 0; + if (G.job_list) + G.last_jobid = G.job_list->jobid; +} + +static void delete_finished_job(struct pipe *pi) +{ + remove_job_from_table(pi); + free_pipe(pi); +} + +static void clean_up_last_dead_job(void) +{ + if (G.job_list && !G.job_list->alive_cmds) + delete_finished_job(G.job_list); +} + +static void insert_job_into_table(struct pipe *pi) +{ + struct pipe *job, **jobp; + int i; + + clean_up_last_dead_job(); + + /* Find the end of the list, and find next job ID to use */ + i = 0; + jobp = &G.job_list; + while ((job = *jobp) != NULL) { + if (job->jobid > i) + i = job->jobid; + jobp = &job->next; + } + pi->jobid = i + 1; + + /* Create a new job struct at the end */ + job = *jobp = xmemdup(pi, sizeof(*pi)); + job->next = NULL; + job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds); + /* Cannot copy entire pi->cmds[] vector! This causes double frees */ + for (i = 0; i < pi->num_cmds; i++) { + job->cmds[i].pid = pi->cmds[i].pid; + /* all other fields are not used and stay zero */ + } + job->cmdtext = xstrdup(get_cmdtext(pi)); + + if (G_interactive_fd) + printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext); + G.last_jobid = job->jobid; +} +#endif /* JOB */ + +static int job_exited_or_stopped(struct pipe *pi) +{ + int rcode, i; + + if (pi->alive_cmds != pi->stopped_cmds) + return -1; + + /* All processes in fg pipe have exited or stopped */ + rcode = 0; + i = pi->num_cmds; + while (--i >= 0) { + rcode = pi->cmds[i].cmd_exitcode; + /* usually last process gives overall exitstatus, + * but with "set -o pipefail", last *failed* process does */ + if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0) + break; + } + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + return rcode; +} + +static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status) +{ +#if ENABLE_HUSH_JOB + struct pipe *pi; +#endif + int i, dead; + + dead = WIFEXITED(status) || WIFSIGNALED(status); + +#if DEBUG_JOBS + if (WIFSTOPPED(status)) + debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", + childpid, WSTOPSIG(status), WEXITSTATUS(status)); + if (WIFSIGNALED(status)) + debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", + childpid, WTERMSIG(status), WEXITSTATUS(status)); + if (WIFEXITED(status)) + debug_printf_jobs("pid %d exited, exitcode %d\n", + childpid, WEXITSTATUS(status)); +#endif + /* Were we asked to wait for a fg pipe? */ + if (fg_pipe) { + i = fg_pipe->num_cmds; + + while (--i >= 0) { + int rcode; + + debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid); + if (fg_pipe->cmds[i].pid != childpid) + continue; + if (dead) { + int ex; + fg_pipe->cmds[i].pid = 0; + fg_pipe->alive_cmds--; + ex = WEXITSTATUS(status); + /* bash prints killer signal's name for *last* + * process in pipe (prints just newline for SIGINT/SIGPIPE). + * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT) + */ + if (WIFSIGNALED(status)) { + int sig = WTERMSIG(status); +#if ENABLE_HUSH_JOB + if (G.run_list_level == 1 + /* ^^^^^ Do not print in nested contexts, example: + * echo `sleep 1; sh -c 'kill -9 $$'` - prints "137", NOT "Killed 137" + */ + && i == fg_pipe->num_cmds-1 + ) { + /* strsignal() is for bash compat. ~600 bloat versus bbox's get_signame() */ + puts(sig == SIGINT || sig == SIGPIPE ? "" : strsignal(sig)); + } +#endif + /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */ + /* MIPS has 128 sigs (1..128), if sig==128, + * 128 + sig would result in exitcode 256 -> 0! + */ + ex = 128 | sig; + } + fg_pipe->cmds[i].cmd_exitcode = ex; + } else { + fg_pipe->stopped_cmds++; + } + debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n", + fg_pipe->alive_cmds, fg_pipe->stopped_cmds); + rcode = job_exited_or_stopped(fg_pipe); + if (rcode >= 0) { +/* Note: *non-interactive* bash does not continue if all processes in fg pipe + * are stopped. Testcase: "cat | cat" in a script (not on command line!) + * and "killall -STOP cat" */ + if (G_interactive_fd) { +#if ENABLE_HUSH_JOB + if (fg_pipe->alive_cmds != 0) + insert_job_into_table(fg_pipe); +#endif + return rcode; + } + if (fg_pipe->alive_cmds == 0) + return rcode; + } + /* There are still running processes in the fg_pipe */ + return -1; + } + /* It wasn't in fg_pipe, look for process in bg pipes */ + } + +#if ENABLE_HUSH_JOB + /* We were asked to wait for bg or orphaned children */ + /* No need to remember exitcode in this case */ + for (pi = G.job_list; pi; pi = pi->next) { + for (i = 0; i < pi->num_cmds; i++) { + if (pi->cmds[i].pid == childpid) + goto found_pi_and_prognum; + } + } + /* Happens when shell is used as init process (init=/bin/sh) */ + debug_printf("checkjobs: pid %d was not in our list!\n", childpid); + return -1; /* this wasn't a process from fg_pipe */ + + found_pi_and_prognum: + if (dead) { + /* child exited */ + int rcode = WEXITSTATUS(status); + if (WIFSIGNALED(status)) + /* NB: not 128 + sig, MIPS has sig 128 */ + rcode = 128 | WTERMSIG(status); + pi->cmds[i].cmd_exitcode = rcode; + if (G.last_bg_pid == pi->cmds[i].pid) + G.last_bg_pid_exitcode = rcode; + pi->cmds[i].pid = 0; + pi->alive_cmds--; + if (!pi->alive_cmds) { +# if ENABLE_HUSH_BASH_COMPAT + G.dead_job_exitcode = job_exited_or_stopped(pi); +# endif + if (G_interactive_fd) { + printf(JOB_STATUS_FORMAT, pi->jobid, + "Done", pi->cmdtext); + delete_finished_job(pi); + } else { +/* + * bash deletes finished jobs from job table only in interactive mode, + * after "jobs" cmd, or if pid of a new process matches one of the old ones + * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source). + * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash. + * We only retain one "dead" job, if it's the single job on the list. + * This covers most of real-world scenarios where this is useful. + */ + if (pi != G.job_list) + delete_finished_job(pi); + } + } + } else { + /* child stopped */ + pi->stopped_cmds++; + } +#endif + return -1; /* this wasn't a process from fg_pipe */ +} + +/* Check to see if any processes have exited -- if they have, + * figure out why and see if a job has completed. + * + * If non-NULL fg_pipe: wait for its completion or stop. + * Return its exitcode or zero if stopped. + * + * Alternatively (fg_pipe == NULL, waitfor_pid != 0): + * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1, + * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for) + * or 0 if no children changed status. + * + * Alternatively (fg_pipe == NULL, waitfor_pid == 0), + * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for) + * or 0 if no children changed status. + */ +static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid) +{ + int attributes; + int status; + int rcode = 0; + + debug_printf_jobs("checkjobs %p\n", fg_pipe); + + attributes = WUNTRACED; + if (fg_pipe == NULL) + attributes |= WNOHANG; + + errno = 0; +#if ENABLE_HUSH_FAST + if (G.handled_SIGCHLD == G.count_SIGCHLD) { +//bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p", +//getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe); + /* There was neither fork nor SIGCHLD since last waitpid */ + /* Avoid doing waitpid syscall if possible */ + if (!G.we_have_children) { + errno = ECHILD; + return -1; + } + if (fg_pipe == NULL) { /* is WNOHANG set? */ + /* We have children, but they did not exit + * or stop yet (we saw no SIGCHLD) */ + return 0; + } + /* else: !WNOHANG, waitpid will block, can't short-circuit */ + } +#endif + +/* Do we do this right? + * bash-3.00# sleep 20 | false + * <ctrl-Z pressed> + * [3]+ Stopped sleep 20 | false + * bash-3.00# echo $? + * 1 <========== bg pipe is not fully done, but exitcode is already known! + * [hush 1.14.0: yes we do it right] + */ + while (1) { + pid_t childpid; +#if ENABLE_HUSH_FAST + int i; + i = G.count_SIGCHLD; +#endif + childpid = waitpid(-1, &status, attributes); + if (childpid <= 0) { + if (childpid && errno != ECHILD) + bb_simple_perror_msg("waitpid"); +#if ENABLE_HUSH_FAST + else { /* Until next SIGCHLD, waitpid's are useless */ + G.we_have_children = (childpid == 0); + G.handled_SIGCHLD = i; +//bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); + } +#endif + /* ECHILD (no children), or 0 (no change in children status) */ + rcode = childpid; + break; + } + rcode = process_wait_result(fg_pipe, childpid, status); + if (rcode >= 0) { + /* fg_pipe exited or stopped */ + break; + } + if (childpid == waitfor_pid) { /* "wait PID" */ + debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status); + rcode = WEXITSTATUS(status); + if (WIFSIGNALED(status)) + rcode = 128 | WTERMSIG(status); + if (WIFSTOPPED(status)) + /* bash: "cmd & wait $!" and cmd stops: $? = 128 | stopsig */ + rcode = 128 | WSTOPSIG(status); + rcode++; + break; /* "wait PID" called us, give it exitcode+1 */ + } +#if ENABLE_HUSH_BASH_COMPAT + if (-1 == waitfor_pid /* "wait -n" (wait for any one job) */ + && G.dead_job_exitcode >= 0 /* some job did finish */ + ) { + debug_printf_exec("waitfor_pid:-1\n"); + rcode = G.dead_job_exitcode + 1; + break; + } +#endif + /* This wasn't one of our processes, or */ + /* fg_pipe still has running processes, do waitpid again */ + } /* while (waitpid succeeds)... */ + + return rcode; +} + +#if ENABLE_HUSH_JOB +static int checkjobs_and_fg_shell(struct pipe *fg_pipe) +{ + pid_t p; + int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/); + if (G_saved_tty_pgrp) { + /* Job finished, move the shell to the foreground */ + p = getpgrp(); /* our process group id */ + debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p); + tcsetpgrp(G_interactive_fd, p); + } + return rcode; +} +#endif + +/* Start all the jobs, but don't wait for anything to finish. + * See checkjobs(). + * + * Return code is normally -1, when the caller has to wait for children + * to finish to determine the exit status of the pipe. If the pipe + * is a simple builtin command, however, the action is done by the + * time run_pipe returns, and the exit code is provided as the + * return value. + * + * Returns -1 only if started some children. IOW: we have to + * mask out retvals of builtins etc with 0xff! + * + * The only case when we do not need to [v]fork is when the pipe + * is single, non-backgrounded, non-subshell command. Examples: + * cmd ; ... { list } ; ... + * cmd && ... { list } && ... + * cmd || ... { list } || ... + * If it is, then we can run cmd as a builtin, NOFORK, + * or (if SH_STANDALONE) an applet, and we can run the { list } + * with run_list. If it isn't one of these, we fork and exec cmd. + * + * Cases when we must fork: + * non-single: cmd | cmd + * backgrounded: cmd & { list } & + * subshell: ( list ) [&] + */ +#if !ENABLE_HUSH_MODE_X +#define redirect_and_varexp_helper(command, sqp, argv_expanded) \ + redirect_and_varexp_helper(command, sqp) +#endif +static int redirect_and_varexp_helper( + struct command *command, + struct squirrel **sqp, + char **argv_expanded) +{ + /* Assignments occur before redirects. Try: + * a=`sleep 1` sleep 2 3>/qwe/rty + */ + + char **new_env = expand_assignments(command->argv, command->assignment_cnt); + dump_cmd_in_x_mode(new_env); + dump_cmd_in_x_mode(argv_expanded); + /* this takes ownership of new_env[i] elements, and frees new_env: */ + set_vars_and_save_old(new_env); + + return setup_redirects(command, sqp); +} +static NOINLINE int run_pipe(struct pipe *pi) +{ + static const char *const null_ptr = NULL; + + int cmd_no; + int next_infd; + struct command *command; + char **argv_expanded; + char **argv; + struct squirrel *squirrel = NULL; + int rcode; + + debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds); + debug_enter(); + + /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*" + * Result should be 3 lines: q w e, qwe, q w e + */ + if (G.ifs_whitespace != G.ifs) + free(G.ifs_whitespace); + G.ifs = get_local_var_value("IFS"); + if (G.ifs) { + char *p; + G.ifs_whitespace = (char*)G.ifs; + p = skip_whitespace(G.ifs); + if (*p) { + /* Not all $IFS is whitespace */ + char *d; + int len = p - G.ifs; + p = skip_non_whitespace(p); + G.ifs_whitespace = xmalloc(len + strlen(p) + 1); /* can overestimate */ + d = mempcpy(G.ifs_whitespace, G.ifs, len); + while (*p) { + if (isspace(*p)) + *d++ = *p; + p++; + } + *d = '\0'; + } + } else { + G.ifs = defifs; + G.ifs_whitespace = (char*)G.ifs; + } + + IF_HUSH_JOB(pi->pgrp = -1;) + pi->stopped_cmds = 0; + command = &pi->cmds[0]; + argv_expanded = NULL; + + if (pi->num_cmds != 1 + || pi->followup == PIPE_BG + || command->cmd_type == CMD_SUBSHELL + ) { + goto must_fork; + } + + pi->alive_cmds = 1; + + debug_printf_exec(": group:%p argv:'%s'\n", + command->group, command->argv ? command->argv[0] : "NONE"); + + if (command->group) { +#if ENABLE_HUSH_FUNCTIONS + if (command->cmd_type == CMD_FUNCDEF) { + /* "executing" func () { list } */ + struct function *funcp; + + funcp = new_function(command->argv[0]); + /* funcp->name is already set to argv[0] */ + funcp->body = command->group; +# if !BB_MMU + funcp->body_as_string = command->group_as_string; + command->group_as_string = NULL; +# endif + command->group = NULL; + command->argv[0] = NULL; + debug_printf_exec("cmd %p has child func at %p\n", command, funcp); + funcp->parent_cmd = command; + command->child_func = funcp; + + debug_printf_exec("run_pipe: return EXIT_SUCCESS\n"); + debug_leave(); + return EXIT_SUCCESS; + } +#endif + /* { list } */ + debug_printf_exec("non-subshell group\n"); + rcode = 1; /* exitcode if redir failed */ + if (setup_redirects(command, &squirrel) == 0) { + debug_printf_exec(": run_list\n"); +//FIXME: we need to pass squirrel down into run_list() +//for SH_STANDALONE case, or else this construct: +// { find /proc/self/fd; true; } >FILE; cmd2 +//has no way of closing saved fd#1 for "find", +//and in SH_STANDALONE mode, "find" is not execed, +//therefore CLOEXEC on saved fd does not help. + rcode = run_list(command->group) & 0xff; + } + restore_redirects(squirrel); + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + debug_leave(); + debug_printf_exec("run_pipe: return %d\n", rcode); + return rcode; + } + + argv = command->argv ? command->argv : (char **) &null_ptr; + { + const struct built_in_command *x; + IF_HUSH_FUNCTIONS(const struct function *funcp;) + IF_NOT_HUSH_FUNCTIONS(enum { funcp = 0 };) + struct variable **sv_shadowed; + struct variable *old_vars; + +#if ENABLE_HUSH_LINENO_VAR + G.execute_lineno = command->lineno; +#endif + + if (argv[command->assignment_cnt] == NULL) { + /* Assignments, but no command. + * Ensure redirects take effect (that is, create files). + * Try "a=t >file" + */ + unsigned i; + G.expand_exitcode = 0; + only_assignments: + rcode = setup_redirects(command, &squirrel); + restore_redirects(squirrel); + + /* Set shell variables */ + i = 0; + while (i < command->assignment_cnt) { + char *p = expand_string_to_string(argv[i], + EXP_FLAG_ESC_GLOB_CHARS, + /*unbackslash:*/ 1 + ); +#if ENABLE_HUSH_MODE_X + if (G_x_mode) { + char *eq; + if (i == 0) + x_mode_prefix(); + x_mode_addchr(' '); + eq = strchrnul(p, '='); + if (*eq) eq++; + x_mode_addblock(p, (eq - p)); + x_mode_print_optionally_squoted(eq); + x_mode_flush(); + } +#endif + debug_printf_env("set shell var:'%s'->'%s'\n", *argv, p); + if (set_local_var(p, /*flag:*/ 0)) { + /* assignment to readonly var / putenv error? */ + rcode = 1; + } + i++; + } + /* Redirect error sets $? to 1. Otherwise, + * if evaluating assignment value set $?, retain it. + * Else, clear $?: + * false; q=`exit 2`; echo $? - should print 2 + * false; x=1; echo $? - should print 0 + * Because of the 2nd case, we can't just use G.last_exitcode. + */ + if (rcode == 0) + rcode = G.expand_exitcode; + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + debug_leave(); + debug_printf_exec("run_pipe: return %d\n", rcode); + return rcode; + } + + /* Expand the rest into (possibly) many strings each */ +#if defined(CMD_TEST2_SINGLEWORD_NOGLOB) + if (command->cmd_type == CMD_TEST2_SINGLEWORD_NOGLOB) + argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt); + else +#endif +#if defined(CMD_SINGLEWORD_NOGLOB) + if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) + argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt); + else +#endif + argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt); + + /* If someone gives us an empty string: `cmd with empty output` */ + if (!argv_expanded[0]) { + free(argv_expanded); + /* `false` still has to set exitcode 1 */ + G.expand_exitcode = G.last_exitcode; + goto only_assignments; + } + + old_vars = NULL; + sv_shadowed = G.shadowed_vars_pp; + + /* Check if argv[0] matches any functions (this goes before bltins) */ + IF_HUSH_FUNCTIONS(funcp = find_function(argv_expanded[0]);) + IF_HUSH_FUNCTIONS(x = NULL;) + IF_HUSH_FUNCTIONS(if (!funcp)) + x = find_builtin(argv_expanded[0]); + if (x || funcp) { + if (x && x->b_function == builtin_exec && argv_expanded[1] == NULL) { + debug_printf("exec with redirects only\n"); + /* + * Variable assignments are executed, but then "forgotten": + * a=`sleep 1;echo A` exec 3>&-; echo $a + * sleeps, but prints nothing. + */ + enter_var_nest_level(); + G.shadowed_vars_pp = &old_vars; + rcode = redirect_and_varexp_helper(command, + /*squirrel:*/ ERR_PTR, + argv_expanded + ); + G.shadowed_vars_pp = sv_shadowed; + /* rcode=1 can be if redir file can't be opened */ + + goto clean_up_and_ret1; + } + + /* Bump var nesting, or this will leak exported $a: + * a=b true; env | grep ^a= + */ + enter_var_nest_level(); + /* Collect all variables "shadowed" by helper + * (IOW: old vars overridden by "var1=val1 var2=val2 cmd..." syntax) + * into old_vars list: + */ + G.shadowed_vars_pp = &old_vars; + rcode = redirect_and_varexp_helper(command, &squirrel, argv_expanded); + if (rcode == 0) { + if (!funcp) { + /* Do not collect *to old_vars list* vars shadowed + * by e.g. "local VAR" builtin (collect them + * in the previously nested list instead): + * don't want them to be restored immediately + * after "local" completes. + */ + G.shadowed_vars_pp = sv_shadowed; + + debug_printf_exec(": builtin '%s' '%s'...\n", + x->b_cmd, argv_expanded[1]); + fflush_all(); + rcode = x->b_function(argv_expanded) & 0xff; + fflush_all(); + } +#if ENABLE_HUSH_FUNCTIONS + else { + debug_printf_exec(": function '%s' '%s'...\n", + funcp->name, argv_expanded[1]); + rcode = run_function(funcp, argv_expanded) & 0xff; + /* + * But do collect *to old_vars list* vars shadowed + * within function execution. To that end, restore + * this pointer _after_ function run: + */ + G.shadowed_vars_pp = sv_shadowed; + } +#endif + } + } else + if (ENABLE_FEATURE_SH_NOFORK && NUM_APPLETS > 1) { + int n = find_applet_by_name(argv_expanded[0]); + if (n < 0 || !APPLET_IS_NOFORK(n)) + goto must_fork; + + enter_var_nest_level(); + /* Collect all variables "shadowed" by helper into old_vars list */ + G.shadowed_vars_pp = &old_vars; + rcode = redirect_and_varexp_helper(command, &squirrel, argv_expanded); + G.shadowed_vars_pp = sv_shadowed; + + if (rcode == 0) { + debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", + argv_expanded[0], argv_expanded[1]); + /* + * Note: signals (^C) can't interrupt here. + * We remember them and they will be acted upon + * after applet returns. + * This makes applets which can run for a long time + * and/or wait for user input ineligible for NOFORK: + * for example, "yes" or "rm" (rm -i waits for input). + */ + rcode = run_nofork_applet(n, argv_expanded); + } + } else + goto must_fork; + + restore_redirects(squirrel); + clean_up_and_ret1: + leave_var_nest_level(); + add_vars(old_vars); + + /* + * Try "usleep 99999999" + ^C + "echo $?" + * with FEATURE_SH_NOFORK=y. + */ + if (!funcp) { + /* It was builtin or nofork. + * if this would be a real fork/execed program, + * it should have died if a fatal sig was received. + * But OTOH, there was no separate process, + * the sig was sent to _shell_, not to non-existing + * child. + * Let's just handle ^C only, this one is obvious: + * we aren't ok with exitcode 0 when ^C was pressed + * during builtin/nofork. + */ + if (sigismember(&G.pending_set, SIGINT)) + rcode = 128 | SIGINT; + } + free(argv_expanded); + IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;) + debug_leave(); + debug_printf_exec("run_pipe return %d\n", rcode); + return rcode; + } + + must_fork: + /* NB: argv_expanded may already be created, and that + * might include `cmd` runs! Do not rerun it! We *must* + * use argv_expanded if it's non-NULL */ + + /* Going to fork a child per each pipe member */ + pi->alive_cmds = 0; + next_infd = 0; + + cmd_no = 0; + while (cmd_no < pi->num_cmds) { + struct fd_pair pipefds; +#if !BB_MMU + int sv_var_nest_level = G.var_nest_level; + volatile nommu_save_t nommu_save; + nommu_save.old_vars = NULL; + nommu_save.argv = NULL; + nommu_save.argv_from_re_execing = NULL; +#endif + command = &pi->cmds[cmd_no]; + cmd_no++; + if (command->argv) { + debug_printf_exec(": pipe member '%s' '%s'...\n", + command->argv[0], command->argv[1]); + } else { + debug_printf_exec(": pipe member with no argv\n"); + } + + /* pipes are inserted between pairs of commands */ + pipefds.rd = 0; + pipefds.wr = 1; + if (cmd_no < pi->num_cmds) + xpiped_pair(pipefds); + +#if ENABLE_HUSH_LINENO_VAR + G.execute_lineno = command->lineno; +#endif + + command->pid = BB_MMU ? fork() : vfork(); + if (!command->pid) { /* child */ +#if ENABLE_HUSH_JOB + disable_restore_tty_pgrp_on_exit(); + CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */ + + /* Every child adds itself to new process group + * with pgid == pid_of_first_child_in_pipe */ + if (G.run_list_level == 1 && G_interactive_fd) { + pid_t pgrp; + pgrp = pi->pgrp; + if (pgrp < 0) /* true for 1st process only */ + pgrp = getpid(); + if (setpgid(0, pgrp) == 0 + && pi->followup != PIPE_BG + && G_saved_tty_pgrp /* we have ctty */ + ) { + /* We do it in *every* child, not just first, + * to avoid races */ + tcsetpgrp(G_interactive_fd, pgrp); + } + } +#endif + if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) { + /* 1st cmd in backgrounded pipe + * should have its stdin /dev/null'ed */ + close(0); + if (open(bb_dev_null, O_RDONLY)) + xopen("/", O_RDONLY); + } else { + xmove_fd(next_infd, 0); + } + xmove_fd(pipefds.wr, 1); + if (pipefds.rd > 1) + close(pipefds.rd); + /* Like bash, explicit redirects override pipes, + * and the pipe fd (fd#1) is available for dup'ing: + * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr + * of cmd1 goes into pipe. + */ + if (setup_redirects(command, NULL)) { + /* Happens when redir file can't be opened: + * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ' + * FOO + * hush: can't open '/qwe/rty': No such file or directory + * BAZ + * (echo BAR is not executed, it hits _exit(1) below) + */ + _exit(1); + } + + /* Stores to nommu_save list of env vars putenv'ed + * (NOMMU, on MMU we don't need that) */ + /* cast away volatility... */ + pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded); + /* pseudo_exec() does not return */ + } + + /* parent or error */ +#if ENABLE_HUSH_FAST + G.count_SIGCHLD++; +//bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); +#endif + enable_restore_tty_pgrp_on_exit(); +#if !BB_MMU + /* Clean up after vforked child */ + free(nommu_save.argv); + free(nommu_save.argv_from_re_execing); + G.var_nest_level = sv_var_nest_level; + remove_nested_vars(); + add_vars(nommu_save.old_vars); +#endif + free(argv_expanded); + argv_expanded = NULL; + if (command->pid < 0) { /* [v]fork failed */ + /* Clearly indicate, was it fork or vfork */ + bb_simple_perror_msg(BB_MMU ? "vfork"+1 : "vfork"); + } else { + pi->alive_cmds++; +#if ENABLE_HUSH_JOB + /* Second and next children need to know pid of first one */ + if (pi->pgrp < 0) + pi->pgrp = command->pid; +#endif + } + + if (cmd_no > 1) + close(next_infd); + if (cmd_no < pi->num_cmds) + close(pipefds.wr); + /* Pass read (output) pipe end to next iteration */ + next_infd = pipefds.rd; + } + + if (!pi->alive_cmds) { + debug_leave(); + debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n"); + return 1; + } + + debug_leave(); + debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds); + return -1; +} + +/* NB: called by pseudo_exec, and therefore must not modify any + * global data until exec/_exit (we can be a child after vfork!) */ +static int run_list(struct pipe *pi) +{ +#if ENABLE_HUSH_CASE + char *case_word = NULL; +#endif +#if ENABLE_HUSH_LOOPS + struct pipe *loop_top = NULL; + char **for_lcur = NULL; + char **for_list = NULL; +#endif + smallint last_followup; + smalluint rcode; +#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE + smalluint cond_code = 0; +#else + enum { cond_code = 0 }; +#endif +#if HAS_KEYWORDS + smallint rword; /* RES_foo */ + smallint last_rword; /* ditto */ +#endif + + debug_printf_exec("run_list start lvl %d\n", G.run_list_level); + debug_enter(); + +#if ENABLE_HUSH_LOOPS + /* Check syntax for "for" */ + { + struct pipe *cpipe; + for (cpipe = pi; cpipe; cpipe = cpipe->next) { + if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN) + continue; + /* current word is FOR or IN (BOLD in comments below) */ + if (cpipe->next == NULL) { + syntax_error("malformed for"); + debug_leave(); + debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); + return 1; + } + /* "FOR v; do ..." and "for v IN a b; do..." are ok */ + if (cpipe->next->res_word == RES_DO) + continue; + /* next word is not "do". It must be "in" then ("FOR v in ...") */ + if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */ + || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */ + ) { + syntax_error("malformed for"); + debug_leave(); + debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level); + return 1; + } + } + } +#endif + + /* Past this point, all code paths should jump to ret: label + * in order to return, no direct "return" statements please. + * This helps to ensure that no memory is leaked. */ + +#if ENABLE_HUSH_JOB + G.run_list_level++; +#endif + +#if HAS_KEYWORDS + rword = RES_NONE; + last_rword = RES_XXXX; +#endif + last_followup = PIPE_SEQ; + rcode = G.last_exitcode; + + /* Go through list of pipes, (maybe) executing them. */ + for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) { + int r; + int sv_errexit_depth; + + if (G.flag_SIGINT) + break; + if (G_flag_return_in_progress == 1) + break; + + IF_HAS_KEYWORDS(rword = pi->res_word;) + debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n", + rword, cond_code, last_rword); + + sv_errexit_depth = G.errexit_depth; + if ( +#if ENABLE_HUSH_IF + rword == RES_IF || rword == RES_ELIF || +#endif + pi->followup != PIPE_SEQ + ) { + G.errexit_depth++; + } +#if ENABLE_HUSH_LOOPS + if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) + && loop_top == NULL /* avoid bumping G.depth_of_loop twice */ + ) { + /* start of a loop: remember where loop starts */ + loop_top = pi; + G.depth_of_loop++; + } +#endif + /* Still in the same "if...", "then..." or "do..." branch? */ + if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) { + if ((rcode == 0 && last_followup == PIPE_OR) + || (rcode != 0 && last_followup == PIPE_AND) + ) { + /* It is "<true> || CMD" or "<false> && CMD" + * and we should not execute CMD */ + debug_printf_exec("skipped cmd because of || or &&\n"); + last_followup = pi->followup; + goto dont_check_jobs_but_continue; + } + } + last_followup = pi->followup; + IF_HAS_KEYWORDS(last_rword = rword;) +#if ENABLE_HUSH_IF + if (cond_code) { + if (rword == RES_THEN) { + /* if false; then ... fi has exitcode 0! */ + G.last_exitcode = rcode = EXIT_SUCCESS; + /* "if <false> THEN cmd": skip cmd */ + continue; + } + } else { + if (rword == RES_ELSE || rword == RES_ELIF) { + /* "if <true> then ... ELSE/ELIF cmd": + * skip cmd and all following ones */ + break; + } + } +#endif +#if ENABLE_HUSH_LOOPS + if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */ + if (!for_lcur) { + /* first loop through for */ + + static const char encoded_dollar_at[] ALIGN1 = { + SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0' + }; /* encoded representation of "$@" */ + static const char *const encoded_dollar_at_argv[] = { + encoded_dollar_at, NULL + }; /* argv list with one element: "$@" */ + char **vals; + + G.last_exitcode = rcode = EXIT_SUCCESS; + vals = (char**)encoded_dollar_at_argv; + if (pi->next->res_word == RES_IN) { + /* if no variable values after "in" we skip "for" */ + if (!pi->next->cmds[0].argv) { + debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n"); + break; + } + vals = pi->next->cmds[0].argv; + } /* else: "for var; do..." -> assume "$@" list */ + /* create list of variable values */ + debug_print_strings("for_list made from", vals); + for_list = expand_strvec_to_strvec(vals); + for_lcur = for_list; + debug_print_strings("for_list", for_list); + } + if (!*for_lcur) { + /* "for" loop is over, clean up */ + free(for_list); + for_list = NULL; + for_lcur = NULL; + break; + } + /* Insert next value from for_lcur */ + /* note: *for_lcur already has quotes removed, $var expanded, etc */ + set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0); + continue; + } + if (rword == RES_IN) { + continue; /* "for v IN list;..." - "in" has no cmds anyway */ + } + if (rword == RES_DONE) { + continue; /* "done" has no cmds too */ + } +#endif +#if ENABLE_HUSH_CASE + if (rword == RES_CASE) { + debug_printf_exec("CASE cond_code:%d\n", cond_code); + case_word = expand_string_to_string(pi->cmds->argv[0], + EXP_FLAG_ESC_GLOB_CHARS, /*unbackslash:*/ 1); + debug_printf_exec("CASE word1:'%s'\n", case_word); + //unbackslash(case_word); + //debug_printf_exec("CASE word2:'%s'\n", case_word); + continue; + } + if (rword == RES_MATCH) { + char **argv; + + debug_printf_exec("MATCH cond_code:%d\n", cond_code); + if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */ + break; + /* all prev words didn't match, does this one match? */ + argv = pi->cmds->argv; + while (*argv) { + char *pattern; + debug_printf_exec("expand_string_to_string('%s')\n", *argv); + pattern = expand_string_to_string(*argv, + EXP_FLAG_ESC_GLOB_CHARS, + /*unbackslash:*/ 0 + ); + /* TODO: which FNM_xxx flags to use? */ + cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0); + debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", + pattern, case_word, cond_code); + free(pattern); + if (cond_code == 0) { + /* match! we will execute this branch */ + free(case_word); + case_word = NULL; /* make future "word)" stop */ + break; + } + argv++; + } + continue; + } + if (rword == RES_CASE_BODY) { /* inside of a case branch */ + debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code); + if (cond_code != 0) + continue; /* not matched yet, skip this pipe */ + } + if (rword == RES_ESAC) { + debug_printf_exec("ESAC cond_code:%d\n", cond_code); + if (case_word) { + /* "case" did not match anything: still set $? (to 0) */ + G.last_exitcode = rcode = EXIT_SUCCESS; + } + } +#endif + /* Just pressing <enter> in shell should check for jobs. + * OTOH, in non-interactive shell this is useless + * and only leads to extra job checks */ + if (pi->num_cmds == 0) { + if (G_interactive_fd) + goto check_jobs_and_continue; + continue; + } + + /* After analyzing all keywords and conditions, we decided + * to execute this pipe. NB: have to do checkjobs(NULL) + * after run_pipe to collect any background children, + * even if list execution is to be stopped. */ + debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds); +#if ENABLE_HUSH_LOOPS + G.flag_break_continue = 0; +#endif + rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */ + if (r != -1) { + /* We ran a builtin, function, or group. + * rcode is already known + * and we don't need to wait for anything. */ + debug_printf_exec(": builtin/func exitcode %d\n", rcode); + G.last_exitcode = rcode; + check_and_run_traps(); +#if ENABLE_HUSH_TRAP && ENABLE_HUSH_FUNCTIONS + rcode = G.last_exitcode; /* "return" in trap can change it, read back */ +#endif +#if ENABLE_HUSH_LOOPS + /* Was it "break" or "continue"? */ + if (G.flag_break_continue) { + smallint fbc = G.flag_break_continue; + /* We might fall into outer *loop*, + * don't want to break it too */ + if (loop_top) { + G.depth_break_continue--; + if (G.depth_break_continue == 0) + G.flag_break_continue = 0; + /* else: e.g. "continue 2" should *break* once, *then* continue */ + } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */ + if (G.depth_break_continue != 0 || fbc == BC_BREAK) { + checkjobs(NULL, 0 /*(no pid to wait for)*/); + break; + } + /* "continue": simulate end of loop */ + rword = RES_DONE; + continue; + } +#endif + if (G_flag_return_in_progress == 1) { + checkjobs(NULL, 0 /*(no pid to wait for)*/); + break; + } + } else if (pi->followup == PIPE_BG) { + /* What does bash do with attempts to background builtins? */ + /* even bash 3.2 doesn't do that well with nested bg: + * try "{ { sleep 10; echo DEEP; } & echo HERE; } &". + * I'm NOT treating inner &'s as jobs */ +#if ENABLE_HUSH_JOB + if (G.run_list_level == 1) + insert_job_into_table(pi); +#endif + /* Last command's pid goes to $! */ + G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid; + G.last_bg_pid_exitcode = 0; + debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n"); +/* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */ + rcode = EXIT_SUCCESS; + goto check_traps; + } else { +#if ENABLE_HUSH_JOB + if (G.run_list_level == 1 && G_interactive_fd) { + /* Waits for completion, then fg's main shell */ + rcode = checkjobs_and_fg_shell(pi); + debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode); + goto check_traps; + } +#endif + /* This one just waits for completion */ + rcode = checkjobs(pi, 0 /*(no pid to wait for)*/); + debug_printf_exec(": checkjobs exitcode %d\n", rcode); + check_traps: + G.last_exitcode = rcode; + check_and_run_traps(); +#if ENABLE_HUSH_TRAP && ENABLE_HUSH_FUNCTIONS + rcode = G.last_exitcode; /* "return" in trap can change it, read back */ +#endif + } + + /* Handle "set -e" */ + if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) { + debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth); + if (G.errexit_depth == 0) + hush_exit(rcode); + } + G.errexit_depth = sv_errexit_depth; + + /* Analyze how result affects subsequent commands */ +#if ENABLE_HUSH_IF + if (rword == RES_IF || rword == RES_ELIF) + cond_code = rcode; +#endif + check_jobs_and_continue: + checkjobs(NULL, 0 /*(no pid to wait for)*/); + dont_check_jobs_but_continue: ; +#if ENABLE_HUSH_LOOPS + /* Beware of "while false; true; do ..."! */ + if (pi->next + && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE) + /* check for RES_DONE is needed for "while ...; do \n done" case */ + ) { + if (rword == RES_WHILE) { + if (rcode) { + /* "while false; do...done" - exitcode 0 */ + G.last_exitcode = rcode = EXIT_SUCCESS; + debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n"); + break; + } + } + if (rword == RES_UNTIL) { + if (!rcode) { + debug_printf_exec(": until expr is true: breaking\n"); + break; + } + } + } +#endif + } /* for (pi) */ + +#if ENABLE_HUSH_JOB + G.run_list_level--; +#endif +#if ENABLE_HUSH_LOOPS + if (loop_top) + G.depth_of_loop--; + free(for_list); +#endif +#if ENABLE_HUSH_CASE + free(case_word); +#endif + debug_leave(); + debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode); + return rcode; +} + +/* Select which version we will use */ +static int run_and_free_list(struct pipe *pi) +{ + int rcode = 0; + debug_printf_exec("run_and_free_list entered\n"); + if (!G.o_opt[OPT_O_NOEXEC]) { + debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds); + rcode = run_list(pi); + } + /* free_pipe_list has the side effect of clearing memory. + * In the long run that function can be merged with run_list, + * but doing that now would hobble the debugging effort. */ + free_pipe_list(pi); + debug_printf_exec("run_and_free_list return %d\n", rcode); + return rcode; +} + + +static void install_sighandlers(unsigned mask) +{ + sighandler_t old_handler; + unsigned sig = 0; + while ((mask >>= 1) != 0) { + sig++; + if (!(mask & 1)) + continue; + old_handler = install_sighandler(sig, pick_sighandler(sig)); + /* POSIX allows shell to re-enable SIGCHLD + * even if it was SIG_IGN on entry. + * Therefore we skip IGN check for it: + */ + if (sig == SIGCHLD) + continue; + /* Interactive bash re-enables SIGHUP which is SIG_IGNed on entry. + * Try: + * trap '' hup; bash; echo RET # type "kill -hup $$", see SIGHUP having effect + * trap '' hup; bash -c 'kill -hup $$; echo ALIVE' # here SIGHUP is SIG_IGNed + */ + if (sig == SIGHUP && G_interactive_fd) + continue; + /* Unless one of the above signals, is it SIG_IGN? */ + if (old_handler == SIG_IGN) { + /* oops... restore back to IGN, and record this fact */ + install_sighandler(sig, old_handler); +#if ENABLE_HUSH_TRAP + if (!G_traps) + G_traps = xzalloc(sizeof(G_traps[0]) * NSIG); + free(G_traps[sig]); + G_traps[sig] = xzalloc(1); /* == xstrdup(""); */ +#endif + } + } +} + +/* Called a few times only (or even once if "sh -c") */ +static void install_special_sighandlers(void) +{ + unsigned mask; + + /* Which signals are shell-special? */ + mask = (1 << SIGQUIT) | (1 << SIGCHLD); + if (G_interactive_fd) { + mask |= SPECIAL_INTERACTIVE_SIGS; + if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */ + mask |= SPECIAL_JOBSTOP_SIGS; + } + /* Careful, do not re-install handlers we already installed */ + if (G.special_sig_mask != mask) { + unsigned diff = mask & ~G.special_sig_mask; + G.special_sig_mask = mask; + install_sighandlers(diff); + } +} + +#if ENABLE_HUSH_JOB +/* helper */ +/* Set handlers to restore tty pgrp and exit */ +static void install_fatal_sighandlers(void) +{ + unsigned mask; + + /* We will restore tty pgrp on these signals */ + mask = 0 + /*+ (1 << SIGILL ) * HUSH_DEBUG*/ + /*+ (1 << SIGFPE ) * HUSH_DEBUG*/ + + (1 << SIGBUS ) * HUSH_DEBUG + + (1 << SIGSEGV) * HUSH_DEBUG + /*+ (1 << SIGTRAP) * HUSH_DEBUG*/ + + (1 << SIGABRT) + /* bash 3.2 seems to handle these just like 'fatal' ones */ + + (1 << SIGPIPE) + + (1 << SIGALRM) + /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs. + * if we aren't interactive... but in this case + * we never want to restore pgrp on exit, and this fn is not called + */ + /*+ (1 << SIGHUP )*/ + /*+ (1 << SIGTERM)*/ + /*+ (1 << SIGINT )*/ + ; + G_fatal_sig_mask = mask; + + install_sighandlers(mask); +} +#endif + +static int set_mode(int state, char mode, const char *o_opt) +{ + int idx; + switch (mode) { + case 'n': + G.o_opt[OPT_O_NOEXEC] = state; + break; + case 'x': + IF_HUSH_MODE_X(G_x_mode = state;) + IF_HUSH_MODE_X(if (G.x_mode_fd <= 0) G.x_mode_fd = dup_CLOEXEC(2, 10);) + break; + case 'e': + G.o_opt[OPT_O_ERREXIT] = state; + break; + case 'o': + if (!o_opt) { + /* "set -o" or "set +o" without parameter. + * in bash, set -o produces this output: + * pipefail off + * and set +o: + * set +o pipefail + * We always use the second form. + */ + const char *p = o_opt_strings; + idx = 0; + while (*p) { + printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p); + idx++; + p += strlen(p) + 1; + } + break; + } + idx = index_in_strings(o_opt_strings, o_opt); + if (idx >= 0) { + G.o_opt[idx] = state; + break; + } + /* fall through to error */ + default: + return EXIT_FAILURE; + } + return EXIT_SUCCESS; +} + +int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int hush_main(int argc, char **argv) +{ + pid_t cached_getpid; + enum { + OPT_login = (1 << 0), + }; + unsigned flags; +#if !BB_MMU + unsigned builtin_argc = 0; +#endif + char **e; + struct variable *cur_var; + struct variable *shell_ver; + + INIT_G(); + if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */ + G.last_exitcode = EXIT_SUCCESS; +#if ENABLE_HUSH_TRAP +# if ENABLE_HUSH_FUNCTIONS + G.return_exitcode = -1; +# endif + G.pre_trap_exitcode = -1; +#endif + +#if ENABLE_HUSH_FAST + G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */ +#endif +#if !BB_MMU + G.argv0_for_re_execing = argv[0]; +#endif + + cached_getpid = getpid(); /* for tcsetpgrp() during init */ + G.root_pid = cached_getpid; /* for $PID (NOMMU can override via -$HEXPID:HEXPPID:...) */ + G.root_ppid = getppid(); /* for $PPID (NOMMU can override) */ + + /* Deal with HUSH_VERSION */ + debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION"); + unsetenv("HUSH_VERSION"); /* in case it exists in initial env */ + shell_ver = xzalloc(sizeof(*shell_ver)); + shell_ver->flg_export = 1; + shell_ver->flg_read_only = 1; + /* Code which handles ${var<op>...} needs writable values for all variables, + * therefore we xstrdup: */ + shell_ver->varstr = xstrdup(hush_version_str); + + /* Create shell local variables from the values + * currently living in the environment */ + G.top_var = shell_ver; + cur_var = G.top_var; + e = environ; + if (e) while (*e) { + char *value = strchr(*e, '='); + if (value) { /* paranoia */ + cur_var->next = xzalloc(sizeof(*cur_var)); + cur_var = cur_var->next; + cur_var->varstr = *e; + cur_var->max_len = strlen(*e); + cur_var->flg_export = 1; + } + e++; + } + /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */ + debug_printf_env("putenv '%s'\n", shell_ver->varstr); + putenv(shell_ver->varstr); + + /* Export PWD */ + set_pwd_var(SETFLAG_EXPORT); + +#if BASH_HOSTNAME_VAR + /* Set (but not export) HOSTNAME unless already set */ + if (!get_local_var_value("HOSTNAME")) { + struct utsname uts; + uname(&uts); + set_local_var_from_halves("HOSTNAME", uts.nodename); + } +#endif + /* IFS is not inherited from the parent environment */ + set_local_var_from_halves("IFS", defifs); + + if (!get_local_var_value("PATH")) + set_local_var_from_halves("PATH", bb_default_root_path); + + /* PS1/PS2 are set later, if we determine that we are interactive */ + + /* bash also exports SHLVL and _, + * and sets (but doesn't export) the following variables: + * BASH=/bin/bash + * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu") + * BASH_VERSION='3.2.0(1)-release' + * HOSTTYPE=i386 + * MACHTYPE=i386-pc-linux-gnu + * OSTYPE=linux-gnu + * PPID=<NNNNN> - we also do it elsewhere + * EUID=<NNNNN> + * UID=<NNNNN> + * GROUPS=() + * LINES=<NNN> + * COLUMNS=<NNN> + * BASH_ARGC=() + * BASH_ARGV=() + * BASH_LINENO=() + * BASH_SOURCE=() + * DIRSTACK=() + * PIPESTATUS=([0]="0") + * HISTFILE=/<xxx>/.bash_history + * HISTFILESIZE=500 + * HISTSIZE=500 + * MAILCHECK=60 + * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:. + * SHELL=/bin/bash + * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor + * TERM=dumb + * OPTERR=1 + * OPTIND=1 + * PS4='+ ' + */ + +#if NUM_SCRIPTS > 0 + if (argc < 0) { + char *script = get_script_content(-argc - 1); + G.global_argv = argv; + G.global_argc = string_array_len(argv); + //install_special_sighandlers(); - needed? + parse_and_run_string(script); + goto final_return; + } +#endif + + /* Initialize some more globals to non-zero values */ + die_func = restore_ttypgrp_and__exit; + + /* Shell is non-interactive at first. We need to call + * install_special_sighandlers() if we are going to execute "sh <script>", + * "sh -c <cmds>" or login shell's /etc/profile and friends. + * If we later decide that we are interactive, we run install_special_sighandlers() + * in order to intercept (more) signals. + */ + + /* Parse options */ + /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */ + flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0; + while (1) { + int opt = getopt(argc, argv, "+" /* stop at 1st non-option */ + "cexinsl" +#if !BB_MMU + "<:$:R:V:" +# if ENABLE_HUSH_FUNCTIONS + "F:" +# endif +#endif + ); + if (opt <= 0) + break; + switch (opt) { + case 'c': + /* Note: -c is not an option with param! + * "hush -c -l SCRIPT" is valid. "hush -cSCRIPT" is not. + */ + G.opt_c = 1; + break; + case 'i': + /* Well, we cannot just declare interactiveness, + * we have to have some stuff (ctty, etc) */ + /* G_interactive_fd++; */ + break; + case 's': + G.opt_s = 1; + break; + case 'l': + flags |= OPT_login; + break; +#if !BB_MMU + case '<': /* "big heredoc" support */ + full_write1_str(optarg); + _exit(0); + case '$': { + unsigned long long empty_trap_mask; + + G.root_pid = bb_strtou(optarg, &optarg, 16); + optarg++; + G.root_ppid = bb_strtou(optarg, &optarg, 16); + optarg++; + G.last_bg_pid = bb_strtou(optarg, &optarg, 16); + optarg++; + G.last_exitcode = bb_strtou(optarg, &optarg, 16); + optarg++; + builtin_argc = bb_strtou(optarg, &optarg, 16); + optarg++; + empty_trap_mask = bb_strtoull(optarg, &optarg, 16); + if (empty_trap_mask != 0) { + IF_HUSH_TRAP(int sig;) + install_special_sighandlers(); +# if ENABLE_HUSH_TRAP + G_traps = xzalloc(sizeof(G_traps[0]) * NSIG); + for (sig = 1; sig < NSIG; sig++) { + if (empty_trap_mask & (1LL << sig)) { + G_traps[sig] = xzalloc(1); /* == xstrdup(""); */ + install_sighandler(sig, SIG_IGN); + } + } +# endif + } +# if ENABLE_HUSH_LOOPS + optarg++; + G.depth_of_loop = bb_strtou(optarg, &optarg, 16); +# endif + /* Suppress "killed by signal" message, -$ hack is used + * for subshells: echo `sh -c 'kill -9 $$'` + * should be silent. + */ + IF_HUSH_JOB(G.run_list_level = 1;) +# if ENABLE_HUSH_FUNCTIONS + /* nommu uses re-exec trick for "... | func | ...", + * should allow "return". + * This accidentally allows returns in subshells. + */ + G_flag_return_in_progress = -1; +# endif + break; + } + case 'R': + case 'V': + set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0); + break; +# if ENABLE_HUSH_FUNCTIONS + case 'F': { + struct function *funcp = new_function(optarg); + /* funcp->name is already set to optarg */ + /* funcp->body is set to NULL. It's a special case. */ + funcp->body_as_string = argv[optind]; + optind++; + break; + } +# endif +#endif + /*case '?': invalid option encountered (set_mode('?') will fail) */ + /*case 'n':*/ + /*case 'x':*/ + /*case 'e':*/ + default: + if (set_mode(1, opt, NULL) == 0) /* no error */ + break; + bb_show_usage(); + } + } /* option parsing loop */ + + /* Skip options. Try "hush -l": $1 should not be "-l"! */ + G.global_argc = argc - (optind - 1); + G.global_argv = argv + (optind - 1); + G.global_argv[0] = argv[0]; + + /* If we are login shell... */ + if (flags & OPT_login) { + const char *hp = NULL; + HFILE *input; + + debug_printf("sourcing /etc/profile\n"); + input = hfopen("/etc/profile"); + run_profile: + if (input != NULL) { + install_special_sighandlers(); + parse_and_run_file(input); + hfclose(input); + } + /* bash: after sourcing /etc/profile, + * tries to source (in the given order): + * ~/.bash_profile, ~/.bash_login, ~/.profile, + * stopping on first found. --noprofile turns this off. + * bash also sources ~/.bash_logout on exit. + * If called as sh, skips .bash_XXX files. + */ + if (!hp) { /* unless we looped on the "goto" already */ + hp = get_local_var_value("HOME"); + if (hp && hp[0]) { + debug_printf("sourcing ~/.profile\n"); + hp = concat_path_file(hp, ".profile"); + input = hfopen(hp); + free((char*)hp); + goto run_profile; + } + } + } + + /* -c takes effect *after* -l */ + if (G.opt_c) { + /* Possibilities: + * sh ... -c 'script' + * sh ... -c 'script' ARG0 [ARG1...] + * On NOMMU, if builtin_argc != 0, + * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...] + * "" needs to be replaced with NULL + * and BARGV vector fed to builtin function. + * Note: the form without ARG0 never happens: + * sh ... -c 'builtin' BARGV... "" + */ + char *script; + + install_special_sighandlers(); + + G.global_argc--; + G.global_argv++; +#if !BB_MMU + if (builtin_argc) { + /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */ + const struct built_in_command *x; + x = find_builtin(G.global_argv[0]); + if (x) { /* paranoia */ + argv = G.global_argv; + G.global_argc -= builtin_argc + 1; /* skip [BARGV...] "" */ + G.global_argv += builtin_argc + 1; + G.global_argv[-1] = NULL; /* replace "" */ + G.last_exitcode = x->b_function(argv); + } + goto final_return; + } +#endif + + script = G.global_argv[0]; + if (!script) + bb_error_msg_and_die(bb_msg_requires_arg, "-c"); + if (!G.global_argv[1]) { + /* -c 'script' (no params): prevent empty $0 */ + G.global_argv[0] = argv[0]; + } else { /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */ + G.global_argc--; + G.global_argv++; + } + parse_and_run_string(script); + goto final_return; + } + + /* -s is: hush -s ARGV1 ARGV2 (no SCRIPT) */ + if (!G.opt_s && G.global_argv[1]) { + HFILE *input; + /* + * "bash <script>" (which is never interactive (unless -i?)) + * sources $BASH_ENV here (without scanning $PATH). + * If called as sh, does the same but with $ENV. + * Also NB, per POSIX, $ENV should undergo parameter expansion. + */ + G.global_argc--; + G.global_argv++; + debug_printf("running script '%s'\n", G.global_argv[0]); + xfunc_error_retval = 127; /* for "hush /does/not/exist" case */ + input = hfopen(G.global_argv[0]); + if (!input) { + bb_simple_perror_msg_and_die(G.global_argv[0]); + } + xfunc_error_retval = 1; + install_special_sighandlers(); + parse_and_run_file(input); +#if ENABLE_FEATURE_CLEAN_UP + hfclose(input); +#endif + goto final_return; + } + /* "implicit" -s: bare interactive hush shows 's' in $- */ + G.opt_s = 1; + + /* Up to here, shell was non-interactive. Now it may become one. + * NB: don't forget to (re)run install_special_sighandlers() as needed. + */ + + /* A shell is interactive if the '-i' flag was given, + * or if all of the following conditions are met: + * no -c command + * no arguments remaining or the -s flag given + * standard input is a terminal + * standard output is a terminal + * Refer to Posix.2, the description of the 'sh' utility. + */ +#if ENABLE_HUSH_JOB + if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) { + G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO); + debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp); + if (G_saved_tty_pgrp < 0) + G_saved_tty_pgrp = 0; + + /* try to dup stdin to high fd#, >= 255 */ + G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254); + if (G_interactive_fd < 0) { + /* try to dup to any fd */ + G_interactive_fd = dup(STDIN_FILENO); + if (G_interactive_fd < 0) { + /* give up */ + G_interactive_fd = 0; + G_saved_tty_pgrp = 0; + } + } + } + debug_printf("interactive_fd:%d\n", G_interactive_fd); + if (G_interactive_fd) { + close_on_exec_on(G_interactive_fd); + + if (G_saved_tty_pgrp) { + /* If we were run as 'hush &', sleep until we are + * in the foreground (tty pgrp == our pgrp). + * If we get started under a job aware app (like bash), + * make sure we are now in charge so we don't fight over + * who gets the foreground */ + while (1) { + pid_t shell_pgrp = getpgrp(); + G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd); + if (G_saved_tty_pgrp == shell_pgrp) + break; + /* send TTIN to ourself (should stop us) */ + kill(- shell_pgrp, SIGTTIN); + } + } + + /* Install more signal handlers */ + install_special_sighandlers(); + + if (G_saved_tty_pgrp) { + /* Set other signals to restore saved_tty_pgrp */ + install_fatal_sighandlers(); + /* Put ourselves in our own process group + * (bash, too, does this only if ctty is available) */ + bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */ + /* Grab control of the terminal */ + tcsetpgrp(G_interactive_fd, cached_getpid); + } + enable_restore_tty_pgrp_on_exit(); + +# if ENABLE_FEATURE_EDITING + G.line_input_state = new_line_input_t(FOR_SHELL); +# if EDITING_HAS_get_exe_name + G.line_input_state->get_exe_name = get_builtin_name; +# endif +# endif +# if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0 + { + const char *hp = get_local_var_value("HISTFILE"); + if (!hp) { + hp = get_local_var_value("HOME"); + if (hp) + hp = concat_path_file(hp, ".hush_history"); + } else { + hp = xstrdup(hp); + } + if (hp) { + G.line_input_state->hist_file = hp; + //set_local_var(xasprintf("HISTFILE=%s", ...)); + } +# if ENABLE_FEATURE_SH_HISTFILESIZE + hp = get_local_var_value("HISTFILESIZE"); + G.line_input_state->max_history = size_from_HISTFILESIZE(hp); +# endif + } +# endif + } else { + install_special_sighandlers(); + } +#elif ENABLE_HUSH_INTERACTIVE + /* No job control compiled in, only prompt/line editing */ + if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) { + G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254); + if (G_interactive_fd < 0) { + /* try to dup to any fd */ + G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, -1); + if (G_interactive_fd < 0) + /* give up */ + G_interactive_fd = 0; + } + } + if (G_interactive_fd) { + close_on_exec_on(G_interactive_fd); + } + install_special_sighandlers(); +#else + /* We have interactiveness code disabled */ + install_special_sighandlers(); +#endif + /* bash: + * if interactive but not a login shell, sources ~/.bashrc + * (--norc turns this off, --rcfile <file> overrides) + */ + + if (G_interactive_fd) { +#if ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT + /* Set (but not export) PS1/2 unless already set */ + if (!get_local_var_value("PS1")) + set_local_var_from_halves("PS1", "\w \$ "); + if (!get_local_var_value("PS2")) + set_local_var_from_halves("PS2", "> "); +#endif + if (!ENABLE_FEATURE_SH_EXTRA_QUIET) { + /* note: ash and hush share this string */ + printf("\n\n%s %s\n" + IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n") + "\n", + bb_banner, + "hush - the humble shell" + ); + } + } + + parse_and_run_file(hfopen(NULL)); /* stdin */ + + final_return: + hush_exit(G.last_exitcode); +} + + +/* + * Built-ins + */ +static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM) +{ + return 0; +} + +#if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL +static NOINLINE int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv)) +{ + int argc = string_array_len(argv); + return applet_main_func(argc, argv); +} +#endif +#if ENABLE_HUSH_TEST || BASH_TEST2 +static int FAST_FUNC builtin_test(char **argv) +{ + return run_applet_main(argv, test_main); +} +#endif +#if ENABLE_HUSH_ECHO +static int FAST_FUNC builtin_echo(char **argv) +{ + return run_applet_main(argv, echo_main); +} +#endif +#if ENABLE_HUSH_PRINTF +static int FAST_FUNC builtin_printf(char **argv) +{ + return run_applet_main(argv, printf_main); +} +#endif + +#if ENABLE_HUSH_HELP +static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM) +{ + const struct built_in_command *x; + + printf( + "Built-in commands:\n" + "------------------\n"); + for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) { + if (x->b_descr) + printf("%-10s%s\n", x->b_cmd, x->b_descr); + } + return EXIT_SUCCESS; +} +#endif + +#if MAX_HISTORY && ENABLE_FEATURE_EDITING +static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM) +{ + show_history(G.line_input_state); + return EXIT_SUCCESS; +} +#endif + +static char **skip_dash_dash(char **argv) +{ + argv++; + if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0') + argv++; + return argv; +} + +static int FAST_FUNC builtin_cd(char **argv) +{ + const char *newdir; + + argv = skip_dash_dash(argv); + newdir = argv[0]; + if (newdir == NULL) { + /* bash does nothing (exitcode 0) if HOME is ""; if it's unset, + * bash says "bash: cd: HOME not set" and does nothing + * (exitcode 1) + */ + const char *home = get_local_var_value("HOME"); + newdir = home ? home : "/"; + } + if (chdir(newdir)) { + /* Mimic bash message exactly */ + bb_perror_msg("cd: %s", newdir); + return EXIT_FAILURE; + } + /* Read current dir (get_cwd(1) is inside) and set PWD. + * Note: do not enforce exporting. If PWD was unset or unexported, + * set it again, but do not export. bash does the same. + */ + set_pwd_var(/*flag:*/ 0); + return EXIT_SUCCESS; +} + +static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM) +{ + puts(get_cwd(0)); + return EXIT_SUCCESS; +} + +static int FAST_FUNC builtin_eval(char **argv) +{ + argv = skip_dash_dash(argv); + + if (!argv[0]) + return EXIT_SUCCESS; + + IF_HUSH_MODE_X(G.x_mode_depth++;) + //bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth); + if (!argv[1]) { + /* bash: + * eval "echo Hi; done" ("done" is syntax error): + * "echo Hi" will not execute too. + */ + parse_and_run_string(argv[0]); + } else { + /* "The eval utility shall construct a command by + * concatenating arguments together, separating + * each with a <space> character." + */ + char *str, *p; + unsigned len = 0; + char **pp = argv; + do + len += strlen(*pp) + 1; + while (*++pp); + str = p = xmalloc(len); + pp = argv; + for (;;) { + p = stpcpy(p, *pp); + pp++; + if (!*pp) + break; + *p++ = ' '; + } + parse_and_run_string(str); + free(str); + } + IF_HUSH_MODE_X(G.x_mode_depth--;) + //bb_error_msg("%s: --x_mode_depth=%d", __func__, G.x_mode_depth); + return G.last_exitcode; +} + +static int FAST_FUNC builtin_exec(char **argv) +{ + argv = skip_dash_dash(argv); + if (argv[0] == NULL) + return EXIT_SUCCESS; /* bash does this */ + + /* Careful: we can end up here after [v]fork. Do not restore + * tty pgrp then, only top-level shell process does that */ + if (G_saved_tty_pgrp && getpid() == G.root_pid) + tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp); + + /* Saved-redirect fds, script fds and G_interactive_fd are still + * open here. However, they are all CLOEXEC, and execv below + * closes them. Try interactive "exec ls -l /proc/self/fd", + * it should show no extra open fds in the "ls" process. + * If we'd try to run builtins/NOEXECs, this would need improving. + */ + //close_saved_fds_and_FILE_fds(); + + /* TODO: if exec fails, bash does NOT exit! We do. + * We'll need to undo trap cleanup (it's inside execvp_or_die) + * and tcsetpgrp, and this is inherently racy. + */ + execvp_or_die(argv); +} + +static int FAST_FUNC builtin_exit(char **argv) +{ + debug_printf_exec("%s()\n", __func__); + + /* interactive bash: + * # trap "echo EEE" EXIT + * # exit + * exit + * There are stopped jobs. + * (if there are _stopped_ jobs, running ones don't count) + * # exit + * exit + * EEE (then bash exits) + * + * TODO: we can use G.exiting = -1 as indicator "last cmd was exit" + */ + + /* note: EXIT trap is run by hush_exit */ + argv = skip_dash_dash(argv); + if (argv[0] == NULL) { +#if ENABLE_HUSH_TRAP + if (G.pre_trap_exitcode >= 0) /* "exit" in trap uses $? from before the trap */ + hush_exit(G.pre_trap_exitcode); +#endif + hush_exit(G.last_exitcode); + } + /* mimic bash: exit 123abc == exit 255 + error msg */ + xfunc_error_retval = 255; + /* bash: exit -2 == exit 254, no error msg */ + hush_exit(xatoi(argv[0]) & 0xff); +} + +#if ENABLE_HUSH_TYPE +/* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */ +static int FAST_FUNC builtin_type(char **argv) +{ + int ret = EXIT_SUCCESS; + + while (*++argv) { + const char *type; + char *path = NULL; + + if (0) {} /* make conditional compile easier below */ + /*else if (find_alias(*argv)) + type = "an alias";*/ +# if ENABLE_HUSH_FUNCTIONS + else if (find_function(*argv)) + type = "a function"; +# endif + else if (find_builtin(*argv)) + type = "a shell builtin"; + else if ((path = find_in_path(*argv)) != NULL) + type = path; + else { + bb_error_msg("type: %s: not found", *argv); + ret = EXIT_FAILURE; + continue; + } + + printf("%s is %s\n", *argv, type); + free(path); + } + + return ret; +} +#endif + +#if ENABLE_HUSH_READ +/* Interruptibility of read builtin in bash + * (tested on bash-4.2.8 by sending signals (not by ^C)): + * + * Empty trap makes read ignore corresponding signal, for any signal. + * + * SIGINT: + * - terminates non-interactive shell; + * - interrupts read in interactive shell; + * if it has non-empty trap: + * - executes trap and returns to command prompt in interactive shell; + * - executes trap and returns to read in non-interactive shell; + * SIGTERM: + * - is ignored (does not interrupt) read in interactive shell; + * - terminates non-interactive shell; + * if it has non-empty trap: + * - executes trap and returns to read; + * SIGHUP: + * - terminates shell (regardless of interactivity); + * if it has non-empty trap: + * - executes trap and returns to read; + * SIGCHLD from children: + * - does not interrupt read regardless of interactivity: + * try: sleep 1 & read x; echo $x + */ +static int FAST_FUNC builtin_read(char **argv) +{ + const char *r; + struct builtin_read_params params; + + memset(&params, 0, sizeof(params)); + + /* "!": do not abort on errors. + * Option string must start with "sr" to match BUILTIN_READ_xxx + */ + params.read_flags = getopt32(argv, +# if BASH_READ_D + IF_NOT_HUSH_BASH_COMPAT("^") + "!srn:p:t:u:d:" IF_NOT_HUSH_BASH_COMPAT("\0" "-1"/*min 1 arg*/), + &params.opt_n, &params.opt_p, &params.opt_t, &params.opt_u, &params.opt_d +# else + IF_NOT_HUSH_BASH_COMPAT("^") + "!srn:p:t:u:" IF_NOT_HUSH_BASH_COMPAT("\0" "-1"/*min 1 arg*/), + &params.opt_n, &params.opt_p, &params.opt_t, &params.opt_u +# endif +//TODO: print "read: need variable name" +//for the case of !BASH "read" with no args (now it fails silently) +//(or maybe extend getopt32() to emit a message if "-1" fails) + ); + if ((uint32_t)params.read_flags == (uint32_t)-1) + return EXIT_FAILURE; + argv += optind; + params.argv = argv; + params.setvar = set_local_var_from_halves; + params.ifs = get_local_var_value("IFS"); /* can be NULL */ + + again: + r = shell_builtin_read(&params); + + if ((uintptr_t)r == 1 && errno == EINTR) { + unsigned sig = check_and_run_traps(); + if (sig != SIGINT) + goto again; + } + + if ((uintptr_t)r > 1) { + bb_simple_error_msg(r); + r = (char*)(uintptr_t)1; + } + + return (uintptr_t)r; +} +#endif + +#if ENABLE_HUSH_UMASK +static int FAST_FUNC builtin_umask(char **argv) +{ + int rc; + mode_t mask; + + rc = 1; + mask = umask(0); + argv = skip_dash_dash(argv); + if (argv[0]) { + mode_t old_mask = mask; + + /* numeric umasks are taken as-is */ + /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */ + if (!isdigit(argv[0][0])) + mask ^= 0777; + mask = bb_parse_mode(argv[0], mask); + if (!isdigit(argv[0][0])) + mask ^= 0777; + if ((unsigned)mask > 0777) { + mask = old_mask; + /* bash messages: + * bash: umask: 'q': invalid symbolic mode operator + * bash: umask: 999: octal number out of range + */ + bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]); + rc = 0; + } + } else { + /* Mimic bash */ + printf("%04o\n", (unsigned) mask); + /* fall through and restore mask which we set to 0 */ + } + umask(mask); + + return !rc; /* rc != 0 - success */ +} +#endif + +#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP +static void print_escaped(const char *s) +{ + if (*s == ''') + goto squote; + do { + const char *p = strchrnul(s, '''); + /* print 'xxxx', possibly just '' */ + printf("'%.*s'", (int)(p - s), s); + if (*p == '\0') + break; + s = p; + squote: + /* s points to '; print "'''...'''" */ + putchar('"'); + do putchar('''); while (*++s == '''); + putchar('"'); + } while (*s); +} +#endif + +#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY +static int helper_export_local(char **argv, unsigned flags) +{ + do { + char *name = *argv; + const char *name_end = endofname(name); + + if (*name_end == '\0') { + struct variable *var, **vpp; + + vpp = get_ptr_to_local_var(name, name_end - name); + var = vpp ? *vpp : NULL; + + if (flags & SETFLAG_UNEXPORT) { + /* export -n NAME (without =VALUE) */ + if (var) { + var->flg_export = 0; + debug_printf_env("%s: unsetenv '%s'\n", __func__, name); + unsetenv(name); + } /* else: export -n NOT_EXISTING_VAR: no-op */ + continue; + } + if (flags & SETFLAG_EXPORT) { + /* export NAME (without =VALUE) */ + if (var) { + var->flg_export = 1; + debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr); + putenv(var->varstr); + continue; + } + } + if (flags & SETFLAG_MAKE_RO) { + /* readonly NAME (without =VALUE) */ + if (var) { + var->flg_read_only = 1; + continue; + } + } +# if ENABLE_HUSH_LOCAL + /* Is this "local" bltin? */ + if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) { + unsigned lvl = flags >> SETFLAG_VARLVL_SHIFT; + if (var && var->var_nest_level == lvl) { + /* "local x=abc; ...; local x" - ignore second local decl */ + continue; + } + } +# endif + /* Exporting non-existing variable. + * bash does not put it in environment, + * but remembers that it is exported, + * and does put it in env when it is set later. + * We just set it to "" and export. + */ + /* Or, it's "local NAME" (without =VALUE). + * bash sets the value to "". + */ + /* Or, it's "readonly NAME" (without =VALUE). + * bash remembers NAME and disallows its creation + * in the future. + */ + name = xasprintf("%s=", name); + } else { + if (*name_end != '=') { + bb_error_msg("'%s': bad variable name", name); + /* do not parse following argv[]s: */ + return 1; + } + /* (Un)exporting/making local NAME=VALUE */ + name = xstrdup(name); + /* Testcase: export PS1='\w $ ' */ + unbackslash(name); + } + debug_printf_env("%s: set_local_var('%s')\n", __func__, name); + if (set_local_var(name, flags)) + return EXIT_FAILURE; + } while (*++argv); + return EXIT_SUCCESS; +} +#endif + +#if ENABLE_HUSH_EXPORT +static int FAST_FUNC builtin_export(char **argv) +{ + unsigned opt_unexport; + +# if ENABLE_HUSH_EXPORT_N + /* "!": do not abort on errors */ + opt_unexport = getopt32(argv, "!n"); + if (opt_unexport == (uint32_t)-1) + return EXIT_FAILURE; + argv += optind; +# else + opt_unexport = 0; + argv++; +# endif + + if (argv[0] == NULL) { + char **e = environ; + if (e) { + while (*e) { +# if 0 + puts(*e++); +# else + /* ash emits: export VAR='VAL' + * bash: declare -x VAR="VAL" + * we follow ash example */ + const char *s = *e++; + const char *p = strchr(s, '='); + + if (!p) /* wtf? take next variable */ + continue; + /* export var= */ + printf("export %.*s", (int)(p - s) + 1, s); + print_escaped(p + 1); + putchar('\n'); +# endif + } + /*fflush_all(); - done after each builtin anyway */ + } + return EXIT_SUCCESS; + } + + return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT); +} +#endif + +#if ENABLE_HUSH_LOCAL +static int FAST_FUNC builtin_local(char **argv) +{ + if (G.func_nest_level == 0) { + bb_error_msg("%s: not in a function", argv[0]); + return EXIT_FAILURE; /* bash compat */ + } + argv++; + /* Since all builtins run in a nested variable level, + * need to use level - 1 here. Or else the variable will be removed at once + * after builtin returns. + */ + return helper_export_local(argv, (G.var_nest_level - 1) << SETFLAG_VARLVL_SHIFT); +} +#endif + +#if ENABLE_HUSH_READONLY +static int FAST_FUNC builtin_readonly(char **argv) +{ + argv++; + if (*argv == NULL) { + /* bash: readonly [-p]: list all readonly VARs + * (-p has no effect in bash) + */ + struct variable *e; + for (e = G.top_var; e; e = e->next) { + if (e->flg_read_only) { +//TODO: quote value: readonly VAR='VAL' + printf("readonly %s\n", e->varstr); + } + } + return EXIT_SUCCESS; + } + return helper_export_local(argv, SETFLAG_MAKE_RO); +} +#endif + +#if ENABLE_HUSH_UNSET +/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unse... */ +static int FAST_FUNC builtin_unset(char **argv) +{ + int ret; + unsigned opts; + + /* "!": do not abort on errors */ + /* "+": stop at 1st non-option */ + opts = getopt32(argv, "!+vf"); + if (opts == (unsigned)-1) + return EXIT_FAILURE; + if (opts == 3) { + bb_simple_error_msg("unset: -v and -f are exclusive"); + return EXIT_FAILURE; + } + argv += optind; + + ret = EXIT_SUCCESS; + while (*argv) { + if (!(opts & 2)) { /* not -f */ + if (unset_local_var(*argv)) { + /* unset <nonexistent_var> doesn't fail. + * Error is when one tries to unset RO var. + * Message was printed by unset_local_var. */ + ret = EXIT_FAILURE; + } + } +# if ENABLE_HUSH_FUNCTIONS + else { + unset_func(*argv); + } +# endif + argv++; + } + return ret; +} +#endif + +#if ENABLE_HUSH_SET +/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set + * built-in 'set' handler + * SUSv3 says: + * set [-abCefhmnuvx] [-o option] [argument...] + * set [+abCefhmnuvx] [+o option] [argument...] + * set -- [argument...] + * set -o + * set +o + * Implementations shall support the options in both their hyphen and + * plus-sign forms. These options can also be specified as options to sh. + * Examples: + * Write out all variables and their values: set + * Set $1, $2, and $3 and set "$#" to 3: set c a b + * Turn on the -x and -v options: set -xv + * Unset all positional parameters: set -- + * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x" + * Set the positional parameters to the expansion of x, even if x expands + * with a leading '-' or '+': set -- $x + * + * So far, we only support "set -- [argument...]" and some of the short names. + */ +static int FAST_FUNC builtin_set(char **argv) +{ + int n; + char **pp, **g_argv; + char *arg = *++argv; + + if (arg == NULL) { + struct variable *e; + for (e = G.top_var; e; e = e->next) + puts(e->varstr); + return EXIT_SUCCESS; + } + + do { + if (strcmp(arg, "--") == 0) { + ++argv; + goto set_argv; + } + if (arg[0] != '+' && arg[0] != '-') + break; + for (n = 1; arg[n]; ++n) { + if (set_mode((arg[0] == '-'), arg[n], argv[1])) { + bb_error_msg("%s: %s: invalid option", "set", arg); + return EXIT_FAILURE; + } + if (arg[n] == 'o' && argv[1]) + argv++; + } + } while ((arg = *++argv) != NULL); + /* Now argv[0] is 1st argument */ + + if (arg == NULL) + return EXIT_SUCCESS; + set_argv: + + /* NB: G.global_argv[0] ($0) is never freed/changed */ + g_argv = G.global_argv; + if (G.global_args_malloced) { + pp = g_argv; + while (*++pp) + free(*pp); + g_argv[1] = NULL; + } else { + G.global_args_malloced = 1; + pp = xzalloc(sizeof(pp[0]) * 2); + pp[0] = g_argv[0]; /* retain $0 */ + g_argv = pp; + } + /* This realloc's G.global_argv */ + G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1); + + G.global_argc = 1 + string_array_len(pp + 1); + + return EXIT_SUCCESS; +} +#endif + +static int FAST_FUNC builtin_shift(char **argv) +{ + int n = 1; + argv = skip_dash_dash(argv); + if (argv[0]) { + n = bb_strtou(argv[0], NULL, 10); + if (errno || n < 0) { + /* shared string with ash.c */ + bb_error_msg("Illegal number: %s", argv[0]); + /* + * ash aborts in this case. + * bash prints error message and set $? to 1. + * Interestingly, for "shift 99999" bash does not + * print error message, but does set $? to 1 + * (and does no shifting at all). + */ + } + } + if (n >= 0 && n < G.global_argc) { + if (G_global_args_malloced) { + int m = 1; + while (m <= n) + free(G.global_argv[m++]); + } + G.global_argc -= n; + memmove(&G.global_argv[1], &G.global_argv[n+1], + G.global_argc * sizeof(G.global_argv[0])); + return EXIT_SUCCESS; + } + return EXIT_FAILURE; +} + +#if ENABLE_HUSH_GETOPTS +static int FAST_FUNC builtin_getopts(char **argv) +{ +/* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html + +TODO: +If a required argument is not found, and getopts is not silent, +a question mark (?) is placed in VAR, OPTARG is unset, and a +diagnostic message is printed. If getopts is silent, then a +colon (:) is placed in VAR and OPTARG is set to the option +character found. + +Test that VAR is a valid variable name? + +"Whenever the shell is invoked, OPTIND shall be initialized to 1" +*/ + char cbuf[2]; + const char *cp, *optstring, *var; + int c, n, exitcode, my_opterr; + unsigned count; + + optstring = *++argv; + if (!optstring || !(var = *++argv)) { + bb_simple_error_msg("usage: getopts OPTSTRING VAR [ARGS]"); + return EXIT_FAILURE; + } + + if (argv[1]) + argv[0] = G.global_argv[0]; /* for error messages in getopt() */ + else + argv = G.global_argv; + cbuf[1] = '\0'; + + my_opterr = 0; + if (optstring[0] != ':') { + cp = get_local_var_value("OPTERR"); + /* 0 if "OPTERR=0", 1 otherwise */ + my_opterr = (!cp || NOT_LONE_CHAR(cp, '0')); + } + + /* getopts stops on first non-option. Add "+" to force that */ + /*if (optstring[0] != '+')*/ { + char *s = alloca(strlen(optstring) + 2); + sprintf(s, "+%s", optstring); + optstring = s; + } + + /* Naively, now we should just + * cp = get_local_var_value("OPTIND"); + * optind = cp ? atoi(cp) : 0; + * optarg = NULL; + * opterr = my_opterr; + * c = getopt(string_array_len(argv), argv, optstring); + * and be done? Not so fast... + * Unlike normal getopt() usage in C programs, here + * each successive call will (usually) have the same argv[] CONTENTS, + * but not the ADDRESSES. Worse yet, it's possible that between + * invocations of "getopts", there will be calls to shell builtins + * which use getopt() internally. Example: + * while getopts "abc" RES -a -bc -abc de; do + * unset -ff func + * done + * This would not work correctly: getopt() call inside "unset" + * modifies internal libc state which is tracking position in + * multi-option strings ("-abc"). At best, it can skip options + * or return the same option infinitely. With glibc implementation + * of getopt(), it would use outright invalid pointers and return + * garbage even _without_ "unset" mangling internal state. + * + * We resort to resetting getopt() state and calling it N times, + * until we get Nth result (or failure). + * (N == G.getopt_count is reset to 0 whenever OPTIND is [un]set). + */ + GETOPT_RESET(); + count = 0; + n = string_array_len(argv); + do { + optarg = NULL; + opterr = (count < G.getopt_count) ? 0 : my_opterr; + c = getopt(n, argv, optstring); + if (c < 0) + break; + count++; + } while (count <= G.getopt_count); + + /* Set OPTIND. Prevent resetting of the magic counter! */ + set_local_var_from_halves("OPTIND", utoa(optind)); + G.getopt_count = count; /* "next time, give me N+1'th result" */ + GETOPT_RESET(); /* just in case */ + + /* Set OPTARG */ + /* Always set or unset, never left as-is, even on exit/error: + * "If no option was found, or if the option that was found + * does not have an option-argument, OPTARG shall be unset." + */ + cp = optarg; + if (c == '?') { + /* If ":optstring" and unknown option is seen, + * it is stored to OPTARG. + */ + if (optstring[1] == ':') { + cbuf[0] = optopt; + cp = cbuf; + } + } + if (cp) + set_local_var_from_halves("OPTARG", cp); + else + unset_local_var("OPTARG"); + + /* Convert -1 to "?" */ + exitcode = EXIT_SUCCESS; + if (c < 0) { /* -1: end of options */ + exitcode = EXIT_FAILURE; + c = '?'; + } + + /* Set VAR */ + cbuf[0] = c; + set_local_var_from_halves(var, cbuf); + + return exitcode; +} +#endif + +static int FAST_FUNC builtin_source(char **argv) +{ + char *arg_path, *filename; + HFILE *input; + save_arg_t sv; + char *args_need_save; +#if ENABLE_HUSH_FUNCTIONS + smallint sv_flg; +#endif + + argv = skip_dash_dash(argv); + filename = argv[0]; + if (!filename) { + /* bash says: "bash: .: filename argument required" */ + return 2; /* bash compat */ + } + arg_path = NULL; + if (!strchr(filename, '/')) { + arg_path = find_in_path(filename); + if (arg_path) + filename = arg_path; + else if (!ENABLE_HUSH_BASH_SOURCE_CURDIR) { + errno = ENOENT; + bb_simple_perror_msg(filename); + return EXIT_FAILURE; + } + } + input = hfopen(filename); + free(arg_path); + if (!input) { + bb_perror_msg("%s", filename); + /* POSIX: non-interactive shell should abort here, + * not merely fail. So far no one complained :) + */ + return EXIT_FAILURE; + } + +#if ENABLE_HUSH_FUNCTIONS + sv_flg = G_flag_return_in_progress; + /* "we are inside sourced file, ok to use return" */ + G_flag_return_in_progress = -1; +#endif + args_need_save = argv[1]; /* used as a boolean variable */ + if (args_need_save) + save_and_replace_G_args(&sv, argv); + + /* "false; . ./empty_line; echo Zero:$?" should print 0 */ + G.last_exitcode = 0; + parse_and_run_file(input); + hfclose(input); + + if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */ + restore_G_args(&sv, argv); +#if ENABLE_HUSH_FUNCTIONS + G_flag_return_in_progress = sv_flg; +#endif + + return G.last_exitcode; +} + +#if ENABLE_HUSH_TRAP +static int FAST_FUNC builtin_trap(char **argv) +{ + int sig; + char *new_cmd; + + if (!G_traps) + G_traps = xzalloc(sizeof(G_traps[0]) * NSIG); + + argv++; + if (!*argv) { + int i; + /* No args: print all trapped */ + for (i = 0; i < NSIG; ++i) { + if (G_traps[i]) { + printf("trap -- "); + print_escaped(G_traps[i]); + /* note: bash adds "SIG", but only if invoked + * as "bash". If called as "sh", or if set -o posix, + * then it prints short signal names. + * We are printing short names: */ + printf(" %s\n", get_signame(i)); + } + } + /*fflush_all(); - done after each builtin anyway */ + return EXIT_SUCCESS; + } + + new_cmd = NULL; + /* If first arg is a number: reset all specified signals */ + sig = bb_strtou(*argv, NULL, 10); + if (errno == 0) { + int ret; + process_sig_list: + ret = EXIT_SUCCESS; + while (*argv) { + sighandler_t handler; + + sig = get_signum(*argv++); + if (sig < 0) { + ret = EXIT_FAILURE; + /* Mimic bash message exactly */ + bb_error_msg("trap: %s: invalid signal specification", argv[-1]); + continue; + } + + free(G_traps[sig]); + G_traps[sig] = xstrdup(new_cmd); + + debug_printf("trap: setting SIG%s (%i) to '%s'\n", + get_signame(sig), sig, G_traps[sig]); + + /* There is no signal for 0 (EXIT) */ + if (sig == 0) + continue; + + if (new_cmd) + handler = (new_cmd[0] ? record_pending_signo : SIG_IGN); + else + /* We are removing trap handler */ + handler = pick_sighandler(sig); + install_sighandler(sig, handler); + } + return ret; + } + + if (!argv[1]) { /* no second arg */ + bb_simple_error_msg("trap: invalid arguments"); + return EXIT_FAILURE; + } + + /* First arg is "-": reset all specified to default */ + /* First arg is "--": skip it, the rest is "handler SIGs..." */ + /* Everything else: set arg as signal handler + * (includes "" case, which ignores signal) */ + if (argv[0][0] == '-') { + if (argv[0][1] == '\0') { /* "-" */ + /* new_cmd remains NULL: "reset these sigs" */ + goto reset_traps; + } + if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */ + argv++; + } + /* else: "-something", no special meaning */ + } + new_cmd = *argv; + reset_traps: + argv++; + goto process_sig_list; +} +#endif + +#if ENABLE_HUSH_JOB +static struct pipe *parse_jobspec(const char *str) +{ + struct pipe *pi; + unsigned jobnum; + + if (sscanf(str, "%%%u", &jobnum) != 1) { + if (str[0] != '%' + || (str[1] != '%' && str[1] != '+' && str[1] != '\0') + ) { + bb_error_msg("bad argument '%s'", str); + return NULL; + } + /* It is "%%", "%+" or "%" - current job */ + jobnum = G.last_jobid; + if (jobnum == 0) { + bb_simple_error_msg("no current job"); + return NULL; + } + } + for (pi = G.job_list; pi; pi = pi->next) { + if (pi->jobid == jobnum) { + return pi; + } + } + bb_error_msg("%u: no such job", jobnum); + return NULL; +} + +static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM) +{ + struct pipe *job; + const char *status_string; + + checkjobs(NULL, 0 /*(no pid to wait for)*/); + for (job = G.job_list; job; job = job->next) { + if (job->alive_cmds == job->stopped_cmds) + status_string = "Stopped"; + else + status_string = "Running"; + + printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext); + } + + clean_up_last_dead_job(); + + return EXIT_SUCCESS; +} + +/* built-in 'fg' and 'bg' handler */ +static int FAST_FUNC builtin_fg_bg(char **argv) +{ + int i; + struct pipe *pi; + + if (!G_interactive_fd) + return EXIT_FAILURE; + + /* If they gave us no args, assume they want the last backgrounded task */ + if (!argv[1]) { + for (pi = G.job_list; pi; pi = pi->next) { + if (pi->jobid == G.last_jobid) { + goto found; + } + } + bb_error_msg("%s: no current job", argv[0]); + return EXIT_FAILURE; + } + + pi = parse_jobspec(argv[1]); + if (!pi) + return EXIT_FAILURE; + found: + /* TODO: bash prints a string representation + * of job being foregrounded (like "sleep 1 | cat") */ + if (argv[0][0] == 'f' && G_saved_tty_pgrp) { + /* Put the job into the foreground. */ + tcsetpgrp(G_interactive_fd, pi->pgrp); + } + + /* Restart the processes in the job */ + debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp); + for (i = 0; i < pi->num_cmds; i++) { + debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid); + } + pi->stopped_cmds = 0; + + i = kill(- pi->pgrp, SIGCONT); + if (i < 0) { + if (errno == ESRCH) { + delete_finished_job(pi); + return EXIT_SUCCESS; + } + bb_simple_perror_msg("kill (SIGCONT)"); + } + + if (argv[0][0] == 'f') { + remove_job_from_table(pi); /* FG job shouldn't be in job table */ + return checkjobs_and_fg_shell(pi); + } + return EXIT_SUCCESS; +} +#endif + +#if ENABLE_HUSH_KILL +static int FAST_FUNC builtin_kill(char **argv) +{ + int ret = 0; + +# if ENABLE_HUSH_JOB + if (argv[1] && strcmp(argv[1], "-l") != 0) { + int i = 1; + + do { + struct pipe *pi; + char *dst; + int j, n; + + if (argv[i][0] != '%') + continue; + /* + * "kill %N" - job kill + * Converting to pgrp / pid kill + */ + pi = parse_jobspec(argv[i]); + if (!pi) { + /* Eat bad jobspec */ + j = i; + do { + j++; + argv[j - 1] = argv[j]; + } while (argv[j]); + ret = 1; + i--; + continue; + } + /* + * In jobs started under job control, we signal + * entire process group by kill -PGRP_ID. + * This happens, f.e., in interactive shell. + * + * Otherwise, we signal each child via + * kill PID1 PID2 PID3. + * Testcases: + * sh -c 'sleep 1|sleep 1 & kill %1' + * sh -c 'true|sleep 2 & sleep 1; kill %1' + * sh -c 'true|sleep 1 & sleep 2; kill %1' + */ + n = G_interactive_fd ? 1 : pi->num_cmds; + dst = alloca(n * sizeof(int)*4); + argv[i] = dst; + if (G_interactive_fd) + dst += sprintf(dst, " -%u", (int)pi->pgrp); + else for (j = 0; j < n; j++) { + struct command *cmd = &pi->cmds[j]; + /* Skip exited members of the job */ + if (cmd->pid == 0) + continue; + /* + * kill_main has matching code to expect + * leading space. Needed to not confuse + * negative pids with "kill -SIGNAL_NO" syntax + */ + dst += sprintf(dst, " %u", (int)cmd->pid); + } + *dst = '\0'; + } while (argv[++i]); + } +# endif + + if (argv[1] || ret == 0) { + ret = run_applet_main(argv, kill_main); + } + /* else: ret = 1, "kill %bad_jobspec" case */ + return ret; +} +#endif + +#if ENABLE_HUSH_WAIT +/* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */ +# if !ENABLE_HUSH_JOB +# define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid) +# endif +static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid) +{ + int ret = 0; + for (;;) { + int sig; + sigset_t oldset; + + if (!sigisemptyset(&G.pending_set)) + goto check_sig; + + /* waitpid is not interruptible by SA_RESTARTed + * signals which we use. Thus, this ugly dance: + */ + + /* Make sure possible SIGCHLD is stored in kernel's + * pending signal mask before we call waitpid. + * Or else we may race with SIGCHLD, lose it, + * and get stuck in sigsuspend... + */ + sigfillset(&oldset); /* block all signals, remember old set */ + sigprocmask2(SIG_SETMASK, &oldset); + + if (!sigisemptyset(&G.pending_set)) { + /* Crap! we raced with some signal! */ + goto restore; + } + + /*errno = 0; - checkjobs does this */ +/* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */ + ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */ + debug_printf_exec("checkjobs:%d\n", ret); +# if ENABLE_HUSH_JOB + if (waitfor_pipe) { + int rcode = job_exited_or_stopped(waitfor_pipe); + debug_printf_exec("job_exited_or_stopped:%d\n", rcode); + if (rcode >= 0) { + ret = rcode; + sigprocmask(SIG_SETMASK, &oldset, NULL); + break; + } + } +# endif + /* if ECHILD, there are no children (ret is -1 or 0) */ + /* if ret == 0, no children changed state */ + /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */ + if (errno == ECHILD || ret) { + ret--; + if (ret < 0) /* if ECHILD, may need to fix "ret" */ + ret = 0; +# if ENABLE_HUSH_BASH_COMPAT + if (waitfor_pid == -1 && errno == ECHILD) { + /* exitcode of "wait -n" with no children is 127, not 0 */ + ret = 127; + } +# endif + sigprocmask(SIG_SETMASK, &oldset, NULL); + break; + } + /* Wait for SIGCHLD or any other signal */ + /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */ + /* Note: sigsuspend invokes signal handler */ + sigsuspend(&oldset); + /* ^^^ add "sigdelset(&oldset, SIGCHLD)" before sigsuspend + * to make sure SIGCHLD is not masked off? + * It was reported that this: + * fn() { : | return; } + * shopt -s lastpipe + * fn + * exec hush SCRIPT + * under bash 4.4.23 runs SCRIPT with SIGCHLD masked, + * making "wait" commands in SCRIPT block forever. + */ + restore: + sigprocmask(SIG_SETMASK, &oldset, NULL); + check_sig: + /* So, did we get a signal? */ + sig = check_and_run_traps(); + if (sig /*&& sig != SIGCHLD - always true */) { + /* Do this for any (non-ignored) signal, not only for ^C */ + ret = 128 | sig; + break; + } + /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */ + } + return ret; +} + +static int FAST_FUNC builtin_wait(char **argv) +{ + int ret; + int status; + + argv = skip_dash_dash(argv); +# if ENABLE_HUSH_BASH_COMPAT + if (argv[0] && strcmp(argv[0], "-n") == 0) { + /* wait -n */ + /* (bash accepts "wait -n PID" too and ignores PID) */ + G.dead_job_exitcode = -1; + return wait_for_child_or_signal(NULL, -1 /*no job, wait for one job*/); + } +# endif + if (argv[0] == NULL) { + /* Don't care about wait results */ + /* Note 1: must wait until there are no more children */ + /* Note 2: must be interruptible */ + /* Examples: + * $ sleep 3 & sleep 6 & wait + * [1] 30934 sleep 3 + * [2] 30935 sleep 6 + * [1] Done sleep 3 + * [2] Done sleep 6 + * $ sleep 3 & sleep 6 & wait + * [1] 30936 sleep 3 + * [2] 30937 sleep 6 + * [1] Done sleep 3 + * ^C <-- after ~4 sec from keyboard + * $ + */ + return wait_for_child_or_signal(NULL, 0 /*no job and no pid to wait for*/); + } + + do { + pid_t pid = bb_strtou(*argv, NULL, 10); + if (errno || pid <= 0) { +# if ENABLE_HUSH_JOB + if (argv[0][0] == '%') { + struct pipe *wait_pipe; + ret = 127; /* bash compat for bad jobspecs */ + wait_pipe = parse_jobspec(*argv); + if (wait_pipe) { + ret = job_exited_or_stopped(wait_pipe); + if (ret < 0) { + ret = wait_for_child_or_signal(wait_pipe, 0); + } else { + /* waiting on "last dead job" removes it */ + clean_up_last_dead_job(); + } + } + /* else: parse_jobspec() already emitted error msg */ + continue; + } +# endif + /* mimic bash message */ + bb_error_msg("wait: '%s': not a pid or valid job spec", *argv); + ret = EXIT_FAILURE; + continue; /* bash checks all argv[] */ + } + + /* Do we have such child? */ + ret = waitpid(pid, &status, WNOHANG); + if (ret < 0) { + /* No */ + ret = 127; + if (errno == ECHILD) { + if (pid == G.last_bg_pid) { + /* "wait $!" but last bg task has already exited. Try: + * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $? + * In bash it prints exitcode 0, then 3. + * In dash, it is 127. + */ + ret = G.last_bg_pid_exitcode; + } else { + /* Example: "wait 1". mimic bash message */ + bb_error_msg("wait: pid %u is not a child of this shell", (unsigned)pid); + } + } else { + /* ??? */ + bb_perror_msg("wait %s", *argv); + } + continue; /* bash checks all argv[] */ + } + if (ret == 0) { + /* Yes, and it still runs */ + ret = wait_for_child_or_signal(NULL, pid); + } else { + /* Yes, and it just exited */ + process_wait_result(NULL, pid, status); + ret = WEXITSTATUS(status); + if (WIFSIGNALED(status)) + ret = 128 | WTERMSIG(status); + } + } while (*++argv); + + return ret; +} +#endif + +#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS +static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min) +{ + if (argv[1]) { + def = bb_strtou(argv[1], NULL, 10); + if (errno || def < def_min || argv[2]) { + bb_error_msg("%s: bad arguments", argv[0]); + def = UINT_MAX; + } + } + return def; +} +#endif + +#if ENABLE_HUSH_LOOPS +static int FAST_FUNC builtin_break(char **argv) +{ + unsigned depth; + if (G.depth_of_loop == 0) { + bb_error_msg("%s: only meaningful in a loop", argv[0]); + /* if we came from builtin_continue(), need to undo "= 1" */ + G.flag_break_continue = 0; + return EXIT_SUCCESS; /* bash compat */ + } + G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */ + + G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1); + if (depth == UINT_MAX) + G.flag_break_continue = BC_BREAK; + if (G.depth_of_loop < depth) + G.depth_break_continue = G.depth_of_loop; + + return EXIT_SUCCESS; +} + +static int FAST_FUNC builtin_continue(char **argv) +{ + G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */ + return builtin_break(argv); +} +#endif + +#if ENABLE_HUSH_FUNCTIONS +static int FAST_FUNC builtin_return(char **argv) +{ + int rc; + + if (G_flag_return_in_progress != -1) { + bb_error_msg("%s: not in a function or sourced script", argv[0]); + return EXIT_FAILURE; /* bash compat */ + } + + G_flag_return_in_progress = 1; + + /* bash: + * out of range: wraps around at 256, does not error out + * non-numeric param: + * f() { false; return qwe; }; f; echo $? + * bash: return: qwe: numeric argument required <== we do this + * 255 <== we also do this + */ + rc = parse_numeric_argv1(argv, G.last_exitcode, 0); +# if ENABLE_HUSH_TRAP + if (argv[1]) { /* "return ARG" inside a running trap sets $? */ + debug_printf_exec("G.return_exitcode=%d\n", rc); + G.return_exitcode = rc; + } +# endif + return rc; +} +#endif + +#if ENABLE_HUSH_TIMES +static int FAST_FUNC builtin_times(char **argv UNUSED_PARAM) +{ + static const uint8_t times_tbl[] ALIGN1 = { + ' ', offsetof(struct tms, tms_utime), + '\n', offsetof(struct tms, tms_stime), + ' ', offsetof(struct tms, tms_cutime), + '\n', offsetof(struct tms, tms_cstime), + 0 + }; + const uint8_t *p; + unsigned clk_tck; + struct tms buf; + + clk_tck = bb_clk_tck(); + + times(&buf); + p = times_tbl; + do { + unsigned sec, frac; + unsigned long t; + t = *(clock_t *)(((char *) &buf) + p[1]); + sec = t / clk_tck; + frac = t % clk_tck; + printf("%um%u.%03us%c", + sec / 60, sec % 60, + (frac * 1000) / clk_tck, + p[0]); + p += 2; + } while (*p); + + return EXIT_SUCCESS; +} +#endif + +#if ENABLE_HUSH_MEMLEAK +static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM) +{ + void *p; + unsigned long l; + +# ifdef M_TRIM_THRESHOLD + /* Optional. Reduces probability of false positives */ + malloc_trim(0); +# endif + /* Crude attempt to find where "free memory" starts, + * sans fragmentation. */ + p = malloc(240); + l = (unsigned long)p; + free(p); + p = malloc(3400); + if (l < (unsigned long)p) l = (unsigned long)p; + free(p); + + +# if 0 /* debug */ + { + struct mallinfo mi = mallinfo(); + printf("top alloc:0x%lx malloced:%d+%d=%d\n", l, + mi.arena, mi.hblkhd, mi.arena + mi.hblkhd); + } +# endif + + if (!G.memleak_value) + G.memleak_value = l; + + l -= G.memleak_value; + if ((long)l < 0) + l = 0; + l /= 1024; + if (l > 127) + l = 127; + + /* Exitcode is "how many kilobytes we leaked since 1st call" */ + return l; +} +#endif