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I am using the command -v "program" >/dev/null 2>&1 construct if I need to POSIX-ly find out if such program is installed in an if-statement.

From its help page is not clear, whether it checks only for path or also for the executable bit?

$ command --help
command: command [-pVv] command [arg ...]
...
      -v    print a description of COMMAND similar to the `type' builtin
...

Thank you.

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  • Careful though that command -v will still consider builtins, which take precedence over executables. Try e.g. command -V test or command -V printf Commented Apr 23, 2023 at 10:06

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command -v uses the PATH to find the executable.

It also checks the permission. If you try command -v a_non_executable_file, nothing will be printed.

You can try strace bash -c 'command -v grep' you will see that the access(2) system call is executed (this system call check the user's permissions for a file). command -v will search in the PATH the first file you can execute.

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