From: Roland Gaudig roland.gaudig@weidmueller.com
Add usage for the setexpr command. It has been added to describe mainly the new setexpr format string operation.
Signed-off-by: Roland Gaudig roland.gaudig@weidmueller.com ---
(no changes since v1)
MAINTAINERS | 1 + doc/usage/index.rst | 1 + doc/usage/setexpr.rst | 148 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 150 insertions(+) create mode 100644 doc/usage/setexpr.rst
diff --git a/MAINTAINERS b/MAINTAINERS index fe53698878..57c3349ef5 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1053,6 +1053,7 @@ SETEXPR M: Roland Gaudig roland.gaudig@weidmueller.com S: Maintained F: cmd/printf.c +F: doc/usage/setexpr.rst
SH M: Marek Vasut marek.vasut+renesas@gmail.com diff --git a/doc/usage/index.rst b/doc/usage/index.rst index 40b796a3a9..719b2c90b9 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -43,6 +43,7 @@ Shell commands reset sbi scp03 + setexpr size true ums diff --git a/doc/usage/setexpr.rst b/doc/usage/setexpr.rst new file mode 100644 index 0000000000..2e511b1290 --- /dev/null +++ b/doc/usage/setexpr.rst @@ -0,0 +1,148 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +setexpr command +=============== + +Synopsis +-------- + +:: + + setexpr[.b, .w, .l .s] <name> [*]<value> <op> [*]<value2> + setexpr[.b, .w, .l] <name> [*]<value> + setexpr <name> fmt <format> [value]... + setexpr <name> gsub r s [t] + setexpr <name> sub r s [t] + +Description +----------- + +The setexpr command is used to set an environment variable to the result +of an evaluation. + +setexpr[.b, .w, .l .s] <name> [*]<value> <op> [*]<value2> + Set environment variable <name> to the result of the evaluated + expression specified by <op>. + +setexpr[.b, .w, .l] name [*]value + Load <value> into environment variable <name> + +setexpr name fmt <format> value + Set environment variable <name> to the result of the C like + format string <format> evaluation of <value>. + +setexpr name gsub <r> <s> [<t>] + For each substring matching the regular expression <r> in the + string <t>, substitute the string <s>. + The result is assigned to <name>. + If <t> is not supplied, use the old value of <name>. + +setexpr name sub <r> <s> [<t>] + Just like gsub(), but replace only the first matching substring + +The setexpr command takes the following arguments: + +format + This parameter contains a C or Bash like format string. + The number of arguments is limited to 4. + The following format types are supported: + + c + single character + d, i + decimal value + o + octal value + s + string + u + unsigned decimal value + x, X + hexadecimal value + '%' + no conversion, instead a % character will be written + + Backslash escapes: + + " = double quote + \ = backslash + \a = alert (bell) + \b = backspace + \c = produce no further output + \f = form feed + \n = new line + \r = carriage return + \t = horizontal tab + \v = vertical tab + \NNN = octal number (NNN is 0 to 3 digits) + +name + The name of the environment variable to be set + +op + '|' + name = value | value2 + '&' + name = value & value2 + '+' + name = value + value2 + (This is the only operator supported for strings. + It acts as concatenation operator on strings) + '^' + name = value ^ value2 + '-' + name = value - value2 + '*' + name = value * value2 + '/' + name = value / value2 + '%' + name = value % value2 + +r + Regular expression + +s + Substitution string + +t + string + +value + Can either be an integer value, a string. + If the pointer prefix '*' is given value is treated as memory address. + +value2 + See value + +Example +------- + +:: + + => setexpr foo fmt %d 0x100 + => echo $foo + 256 + => + + => setexpr foo fmt 0x%08x 63 + => echo $foo + 0x00000063 + => + + => setexpr foo fmt %%%o 8 + => echo $foo + %10 + => + +Configuration +------------- + +The setexpr gsub and sub operations are only available if CONFIG_REGEX=y. + +Return value +------------ + +The return value $? is set to 0 (true) if the operation was successful. + +If an error occurs, the return value $? is set to 1 (false).