The traditional way to grab the output from a shell script is to use command substitution. Unfortunately, we don't really have the concept of pipes in U-Boot (at least not without console recording). Even if we did, stdout is severely polluted by informational printfs.
Instead of redirecting stdout, instead use a special global variable. This lets commands set a result without having to modify the function signature of every command, and everything that calls commands. This is a bit of a hack, but seemed like the least-invasive of all options.
Currently, the value of cmd_result is printed if it is set. This makes sense for things like echo, where you can do something like
=> echo a b c d e a b c d e => var=c => echo a $(echo b $var d) e a b c d e
but it makes less sense for some other commands
All callers of cmd_process must 1. Print cmd_result (unless it is being "redirected") 2. free() cmd_result 3. set cmd_result to NULL Calling cmd_process with a non-NULL value in cmd_result is a bug.
Signed-off-by: Sean Anderson seanga2@gmail.com ---
common/cli_hush.c | 39 ++++++++++++++++++++++++++++--- common/cli_simple.c | 8 ++++++- common/command.c | 3 +++ include/asm-generic/global_data.h | 4 ++++ 4 files changed, 50 insertions(+), 4 deletions(-)
diff --git a/common/cli_hush.c b/common/cli_hush.c index 83329763c6..8fed7eb14e 100644 --- a/common/cli_hush.c +++ b/common/cli_hush.c @@ -475,6 +475,8 @@ static char *make_string(char **inp, int *nonnull); static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input); #ifndef __U_BOOT__ static int parse_string(o_string *dest, struct p_context *ctx, const char *src); +#else +static void update_ifs_map(void); #endif static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger); /* setup: */ @@ -1673,6 +1675,10 @@ static int run_pipe_real(struct pipe *pi) "'run' command\n", child->argv[i]); return -1; } + if (gd->cmd_result) + puts(gd->cmd_result); + free(gd->cmd_result); + gd->cmd_result = NULL; /* Process the command */ return cmd_process(flag, child->argc - i, child->argv + i, &flag_repeat, NULL); @@ -2683,6 +2689,7 @@ FILE *generate_stream_from_list(struct pipe *head) #endif return pf; } +#endif /* __U_BOOT__ */
/* this version hacked for testing purposes */ /* return code is exit status of the process that is run. */ @@ -2691,7 +2698,11 @@ static int process_command_subs(o_string *dest, struct p_context *ctx, struct in int retcode; o_string result=NULL_O_STRING; struct p_context inner; +#ifdef __U_BOOT__ + int list_retcode; +#else FILE *p; +#endif struct in_str pipe_str; initialize_context(&inner);
@@ -2702,13 +2713,21 @@ static int process_command_subs(o_string *dest, struct p_context *ctx, struct in done_pipe(&inner, PIPE_SEQ); b_free(&result);
+#ifdef __U_BOOT__ + list_retcode = run_list_real(inner.list_head); + setup_string_in_str(&pipe_str, gd->cmd_result ?: ""); + /* Restore the original map as best we can */ + update_ifs_map(); +#else p=generate_stream_from_list(inner.list_head); if (p==NULL) return 1; mark_open(fileno(p)); setup_file_in_str(&pipe_str, p); +#endif
/* now send results of command back into original context */ retcode = parse_stream(dest, ctx, &pipe_str, '\0'); +#ifndef __U_BOOT__ /* XXX In case of a syntax error, should we try to kill the child? * That would be tough to do right, so just read until EOF. */ if (retcode == 1) { @@ -2723,12 +2742,18 @@ static int process_command_subs(o_string *dest, struct p_context *ctx, struct in * to the KISS philosophy of this program. */ mark_closed(fileno(p)); retcode=pclose(p); +#else + free(gd->cmd_result); + gd->cmd_result = NULL; + retcode = list_retcode; +#endif free_pipe_list(inner.list_head,0); debug_printf("pclosed, retcode=%d\n",retcode); /* XXX this process fails to trim a single trailing newline */ return retcode; }
+#ifndef __U_BOOT__ static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch) { @@ -2896,11 +2921,11 @@ static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *i } b_addchr(dest, SPECIAL_VAR_SYMBOL); break; -#ifndef __U_BOOT__ case '(': b_getch(input); process_command_subs(dest, ctx, input, ')'); break; +#ifndef __U_BOOT__ case '*': sep[0]=ifs[0]; for (i=1; i<global_argc; i++) { @@ -3165,7 +3190,7 @@ static void update_ifs_map(void) mapset(subst, 3); /* never flow through */ } mapset((uchar *)"\$'"", 3); /* never flow through */ - mapset((uchar *)";&|#", 1); /* flow through if quoted */ + mapset((uchar *)";&|()#", 1); /* flow through if quoted */ #endif mapset(ifs, 2); /* also flow through if quoted */ } @@ -3185,7 +3210,8 @@ static int parse_stream_outer(struct in_str *inp, int flag) ctx.type = flag; initialize_context(&ctx); update_ifs_map(); - if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0); + if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) + mapset((uchar *)";$&|()", 0); inp->promptmode=1; rcode = parse_stream(&temp, &ctx, inp, flag & FLAG_CONT_ON_NEWLINE ? -1 : '\n'); @@ -3205,6 +3231,13 @@ static int parse_stream_outer(struct in_str *inp, int flag) run_list(ctx.list_head); #else code = run_list(ctx.list_head); + + if (!(flag & FLAG_REPARSING) && gd->cmd_result) { + puts(gd->cmd_result); + free(gd->cmd_result); + gd->cmd_result = NULL; + } + if (code == -2) { /* exit */ b_free(&temp); code = 0; diff --git a/common/cli_simple.c b/common/cli_simple.c index e80ba488a5..5df30d964f 100644 --- a/common/cli_simple.c +++ b/common/cli_simple.c @@ -15,14 +15,16 @@ #include <console.h> #include <env.h> #include <log.h> +#include <malloc.h> #include <linux/ctype.h>
+DECLARE_GLOBAL_DATA_PTR; + #define DEBUG_PARSER 0 /* set to 1 to debug */
#define debug_parser(fmt, args...) \ debug_cond(DEBUG_PARSER, fmt, ##args)
- int cli_simple_parse_line(char *line, char *argv[]) { int nargs = 0; @@ -257,6 +259,10 @@ int cli_simple_run_command(const char *cmd, int flag)
if (cmd_process(flag, argc, argv, &repeatable, NULL)) rc = -1; + if (gd->cmd_result) + puts(gd->cmd_result); + free(gd->cmd_result); + gd->cmd_result = NULL;
/* Did the user stop this? */ if (had_ctrlc()) diff --git a/common/command.c b/common/command.c index 3fe6791eda..952a8f00eb 100644 --- a/common/command.c +++ b/common/command.c @@ -588,6 +588,9 @@ enum command_ret_t cmd_process(int flag, int argc, char *const argv[], enum command_ret_t rc = CMD_RET_SUCCESS; struct cmd_tbl *cmdtp;
+ /* Clear previous result */ + assert(!gd->cmd_result); + #if defined(CONFIG_SYS_XTRACE) char *xtrace;
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h index b6a9991fc9..85262d9566 100644 --- a/include/asm-generic/global_data.h +++ b/include/asm-generic/global_data.h @@ -453,6 +453,10 @@ struct global_data { */ char *smbios_version; #endif + /** + * @cmd_result: Result of the current command + */ + char *cmd_result; };
/**