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Zsh function to run a command and capture its status, stdout and stderr
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# Runs "$@" in a subshell with the caller's options, sets reply=(stdout stderr) | |
# and returns the status of the executed command. Both stdout and stderr are | |
# captured completely, including NUL bytes, incomplete UTF-8 characters and | |
# trailing LF, if any. | |
# | |
# Example: | |
# | |
# % zsh-run-command ls -d ~ /garbage | |
# % printf 'status: %s\nstdout: %s\nstderr: %s\n' $? "${(q+)reply[@]}" | |
# status: 2 | |
# stdout: $'/home/romka\n' | |
# stderr: $'ls: cannot access \'/garbage\': No such file or directory\n' | |
# | |
# Note that aliases in "$@" don't get expanded. If you need to run a command | |
# with alias expansion, use eval: | |
# | |
# % zsh-run-command eval 'foo bar' | |
# | |
# Implementation notes: | |
# | |
# - Don't change shell options before running the command. The caller's | |
# options may be important for it. | |
# - Be mindful of err_return and err_exit that may be set by the caller. | |
# - Don't change `reply` before running the command. It might be using it. | |
# - Don't assume that the output of the command is text. It can be binary data. | |
# - Remember that $(...) strips trailing LF. | |
# - Don't change any file descriptors except for 1 and 2 because the command | |
# might be using them. | |
# - Make sure that commands such as `exit` and `return 12345` work. | |
# - Think what would happen if the command kills its parent process, or if zsh | |
# cannot fork. | |
# - Use ugly names for parameters in scope of the command to avoid hiding | |
# globals that it might use. | |
# - Quote everything to prevent alias expansion. | |
# - Prefix all builtins with 'builtin' to avoid invoking user-defined functions. | |
zsh-run-command() { | |
'builtin' 'local' '__zrc' | |
__zrc="$( | |
__zrc="$( ("$@") || __zrc="$?"; 'builtin' 'printf' '%3d' "$__zrc")" 2>&1 || | |
'builtin' 'printf' '-v' '__zrc' '%3d' "$?" | |
'builtin' 'unsetopt' 'multibyte' | |
'builtin' 'printf' '%s%18d' "$__zrc" "${#__zrc}" | |
)" || 'builtin' 'printf' '-v' '__zrc' '%3d%18d' "$?" '3' | |
'builtin' 'emulate' '-L' 'zsh' '-o' 'no_multibyte' | |
'builtin' 'local' '-i' n='__zrc[-18,-1]' | |
'builtin' 'typeset' '-ga' 'reply' | |
'builtin' 'set' '-A' 'reply' "$__zrc[-n-18,-22]" "$__zrc[1,-n-19]" | |
'builtin' 'return' '__zrc[-21,-19]' | |
} |
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Thanks :-)