how to get non-blocking file descriptors from a popen?

[Kragen Sitaker]

"Gregory P. Smith" <gsmith-mysterymeat at mysterymeat-transmeta.com> writes:
> Using os.popen (or better, popen2.Popen4 objects), how can I switch the 
> returned file objects to non-blocking io mode for appropriate use with 
> select.poll?

Well, it varies from OS to OS, but this generally works on Unix:

            flags = fcntl.fcntl (fd, FCNTL.F_GETFL, 0)
            flags = flags | FCNTL.O_NONBLOCK
            fcntl.fcntl (fd, FCNTL.F_SETFL, flags)