Question

I am trying to spawn a process using Popen and send it a particular string to its stdin.

I have:

pipe = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE)
pipe.communicate( my_stdin_str.encode(encoding='ascii') )
pipe.stdin.close()

However, the second line actually escapes the whitespace in my_stdin_str. For example, if I have:

my_stdin_str="This is a string"

The process will see:

This\ is\ a\ string

How can I prevent this behaviour?

Answer 1

Unless you know you need it for some reason, don’t run with “shell=True” in general (which, without testing, sounds like what’s going on here).