Question

I am trying to pass a string literal to a Popen command, but it is isn’t working:

subprocess.Popen(['/usr/bin/festival', '-b', '(SayText "%s")']) % text

The idea is that I want to pass text into the Popen command, which calls the program festival, which will read the input text.

Is it possible to pass a string literal inside a popen command? My guess is that this isn’t working because the Popen commands are in a list.

Answer 1

You are correct, format the list element, and not the result of Popen or the argument list:

festivalCmd = '(SayText "%s")' % text.replace('"', '')
subprocess.Popen(['/usr/bin/festival', '-b', festivalCmd])

The call to replace ensures that you’re correctly handing inputs like foo"bar without failing.