pythonshellsubprocess

Does the `shell` in `shell=True` in subprocess mean `bash`?

I was wondering whether

subprocess.call("if [ ! -d '{output}' ]; then mkdir -p {output}; fi", shell=True)

will be interpreted by sh or zsh instead of bash in different servers.

What should I do to make sure that it's interpreted by bash?

Solution

  • http://docs.python.org/2/library/subprocess.html

    On Unix with shell=True, the shell defaults to /bin/sh

    Note that /bin/sh is often symlinked to something different, e.g. on ubuntu:

    $ ls -la /bin/sh
lrwxrwxrwx 1 root root 4 Mar 29  2012 /bin/sh -> dash

    You can use the executable argument to replace the default:

    ... If shell=True, on Unix the executable argument specifies a replacement shell for the default /bin/sh.

    subprocess.call("if [ ! -d '{output}' ]; then mkdir -p {output}; fi",
                shell=True,
                executable="/bin/bash")