Python-Nonblocking-subprocess

 import subprocess
 import select
 import os
 import sys
 import fcntl
 
 
p1 = subprocess.Popen("sleep 2 && echo done1 && sleep 5 && echo done2",
 shell=True, stdout=subprocess.PIPE)
 p2 = subprocess.Popen("sleep 3 && echo done3 && sleep 5 && echo done4",
 shell=True, stdout=subprocess.PIPE)
 
 
pout = [p1.stdout.fileno(), p2.stdout.fileno()]
 for fd in pout:
 fl = fcntl.fcntl(fd, fcntl.F_GETFL)
 fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
 
 
fd1_closed, fd2_closed = 0, 0
 while not (fd1_closed and fd2_closed):
 inputready, outputready, exceptready = select.select(pout, [], [])
 for s in inputready:
 got = os.read(s, 1)
 if got:
 print "got output %s from fd %d" % (got, s)
 else:
 if s == pout[0]:
 fd1_closed = 1
 elif s == pout[1]:
 fd2_closed = 1
 else:
 pass
 

output:

 

 got output d from fd 3
 got output o from fd 3
 got output n from fd 3
 got output e from fd 3
 got output 1 from fd 3
 got output
 from fd 3
 got output d from fd 4
 got output o from fd 4
 got output n from fd 4
 got output e from fd 4
 got output 3 from fd 4
 got output
 from fd 4
 got output d from fd 3
 got output o from fd 3
 got output n from fd 3
 got output e from fd 3
 got output 2 from fd 3
 got output
 from fd 3
 got output d from fd 4
 got output o from fd 4
 got output n from fd 4
 got output e from fd 4
 got output 4 from fd 4
 got output
 from fd 4