python shell command stdout code example

Example 1: python run command and read output

#!/usr/bin/python
import subprocess, sys
## command to run - tcp only ##
cmd = "/usr/sbin/netstat -p tcp -f inet"
## run it ##
p = subprocess.Popen(cmd, shell=True, stderr=subprocess.PIPE)
## But do not wait till netstat finish, start displaying output immediately ##
while True:
    out = p.stderr.read(1)
    if out == '' and p.poll() != None:
        break
    if out != '':
        sys.stdout.write(out)
        sys.stdout.flush()

Example 2: python execute shell command and get output

import subprocess
process = subprocess.Popen(['echo', 'More output'],
                     stdout=subprocess.PIPE, 
                     stderr=subprocess.PIPE)
stdout, stderr = process.communicate()
stdout, stderr