Store output of subprocess.Popen call in a string

Question

I\'m trying to make a system call in Python and store the output to a string that I can manipulate in the Python program.

#!/usr/bin/python
import subprocess         


        

Answer 1

subprocess.Popen: http://docs.python.org/2/library/subprocess.html#subprocess.Popen

import subprocess

command = "ntpq -p"  # the shell command
process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=None, shell=True)

#Launch the shell command:
output = process.communicate()

print output[0]

In the Popen constructor, if shell is True, you should pass the command as a string rather than as a sequence. Otherwise, just split the command into a list:

command = ["ntpq", "-p"]  # the shell command
process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=None)

If you need to read also the standard error, into the Popen initialization, you can set stderr to subprocess.PIPE or to subprocess.STDOUT:

import subprocess

command = "ntpq -p"  # the shell command
process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)

#Launch the shell command:
output, error = process.communicate()