On Saturday, September 7, 2013 9:47:47 AM UTC-6, Nobody wrote: > On Sat, 07 Sep 2013 03:55:02 -0700, larry.mart...@gmail.com wrote: > > > > > I have a python script and when I run it directly from the command line > > > it runs to completion. But I need to run it from another script. I do > > > that like this: > > > > > > p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT) > > > rv = p.wait() > > > out_buf = p.stdout.read() > > > > > > When I do this, wait never returns. > > > > The last two statements are the wrong way around. If you're reading a > > process' output via a pipe, you shouldn't wait() for it until it has > > closed its end of the pipe. > > > > As it stands, you have a potential deadlock. If the subprocess tries to > > write more data than will fit into the pipe, it will block until the > > parent reads from the pipe. But the parent won't read from the pipe until > > after the subprocess has terminated, which won't happen because the > > subprocess is blocked waiting for the parent to read from the pipe ...
Thanks. I reversed the order of the wait and read calls, and it no longer hangs. -- https://mail.python.org/mailman/listinfo/python-list
