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diff --git a/meson/docs/markdown/External-commands.md b/meson/docs/markdown/External-commands.md new file mode 100644 index 000000000..be9d171b6 --- /dev/null +++ b/meson/docs/markdown/External-commands.md @@ -0,0 +1,52 @@ +--- +short-description: Running external commands +... + +# External commands + +As a part of the software configuration, you may want to get extra +data by running external commands. The basic syntax is the following. + +```meson +r = run_command('command', 'arg1', 'arg2', 'arg3') +if r.returncode() != 0 + # it failed +endif +output = r.stdout().strip() +errortxt = r.stderr().strip() +``` + +Since 0.52.0, you can pass the command environment as a dictionary: + +```meson +run_command('command', 'arg1', 'arg2', env: {'FOO': 'bar'}) +``` + +Since 0.50.0, you can also pass the command +[`environment`](Reference-manual.md#environment-object) object: + +```meson +env = environment() +env.set('FOO', 'bar') +run_command('command', 'arg1', 'arg2', env: env) +``` + +The `run_command` function returns an object that can be queried for +return value and text written to stdout and stderr. The `strip` method +call is used to strip trailing and leading whitespace from strings. +Usually output from command line programs ends in a newline, which is +unwanted in string variables. The first argument can be either a +string or an executable you have detected earlier with `find_program`. + +Meson will autodetect scripts with a shebang line and run them with +the executable/interpreter specified in it both on Windows and on +Unixes. + +Note that you can not pass your command line as a single string. That +is, calling `run_command('do_something foo bar')` will not work. You +must either split up the string into separate arguments or pass the +split command as an array. It should also be noted that Meson will not +pass the command to the shell, so any command lines that try to use +things such as environment variables, backticks or pipelines will not +work. If you require shell semantics, write your command into a script +file and call that with `run_command`. |