popen_async.py

#!/usr/bin/env python

import subprocess
import threading
import time

def call_async(on_exit, *popen_args, **popen_kw_args):

    def run_in_thread(on_exit):
        result_code = proc.wait()
        if result_code == 0:
            return on_exit(None, proc)
        else:
            return on_exit(result_code, proc)

    proc = subprocess.Popen(*popen_args, **popen_kw_args)
    thread = threading.Thread(target=run_in_thread, args=[on_exit])
    thread.start()
    return proc

def on_complete(rc):
    print "complete: " + str(rc)
    print "--- %s seconds ---" % (time.time() - start_time)

start_time = time.time()

proc = call_async(on_complete, [
    "rec", "aaaa.wav"
], cwd="tests")

print "delay"
time.sleep(3)

print "ending"
proc.kill()

print "stopped"