Re: [PATCH v2 1/2] usertools/devbind: update coding style

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue,  3 Dec 2024 11:25:00 +0000
Anatoly Burakov <anatoly.burakov@intel.com> wrote:

> +
> +def check_installed(program: str, package: str) -> None:
> +    """Check if a program is installed."""
> +    if subprocess.call(
> +        ["which", program], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL
> +    ):
> +        raise DevbindError(f"'{program}' not found - please install '{package}'.")
> +

Apparently the posix way to do this is to use command -v not "which"


       command [-pVv] command [arg ...]
              Run  command  with  args  suppressing  the  normal shell function
              lookup.  Only builtin commands or commands found in the PATH  are
              executed.   If  the -p option is given, the search for command is
              performed using a default value for PATH that  is  guaranteed  to
              find  all  of the standard utilities.  If either the -V or -v op‐
              tion is supplied, a description of command is  printed.   The  -v
              option  causes  a  single word indicating the command or filename
              used to invoke command to be displayed; the -V option produces  a
              more  verbose  description.   If the -V or -v option is supplied,
              the exit status is 0 if command was found, and 1 if not.  If nei‐
              ther option is supplied and an error occurred or  command  cannot
              be  found, the exit status is 127.  Otherwise, the exit status of
              the command builtin is the exit status of command.