Python's subprocess.Popen object hangs gathering child output when child process does not exit

Question

When a process exits abnormally or not at all, I still want to be able to gather what output it may have generated up until that point.

The obvious solution to this

Answer 1

Problem is that bash doesn't answer to CTRL-C when not connected with a terminal. Switching to SIGHUP or SIGTERM seems to do the trick:

cmd = ["bash", 'childProc.sh']
p = subprocess.Popen(cmd, stdout=subprocess.PIPE, 
                          stderr=subprocess.STDOUT, 
                          close_fds=True)
time.sleep(3)
print 'killing pid', p.pid
os.kill(p.pid, signal.SIGTERM)
print "timed out and killed child, collecting what output exists so far"
out  = p.communicate()[0]
print "got it", out

Outputs:

killing pid 5844
timed out and killed child, collecting what output exists so far
got it output line 0
output line 1
output line 2