Saving stdout from subprocess.Popen to file, plus writing more stuff to the file

Question

I\'m writing a python script that uses subprocess.Popen to execute two programs (from compiled C code) which each produce stdout. The script gets that output and saves it to

Answer 1

You need to wait until the process is finished before you continue. I've also converted the code to use a context manager, which is cleaner.

def run(cmd, logfile):
    p = subprocess.Popen(cmd, shell=True, universal_newlines=True, stdout=logfile)
    p.wait()
    return p

def runTest(path, flags, name):
    with open(name, "w") as log:
        print >> log, "Calling executable A"
        a_ret = run(path + "executable_a_name" + flags, log)
        print >> log, "Calling executable B"
        b_ret = run(path + "executable_b_name" + flags, log)
        print >> log, "More stuff"