#!/usr/bin/env python

# -*- coding: utf-8 -*-

import os

import sys

print "I'm going to fork now - the child will write something to a pipe, and the parent will read it back"

processName = "parent"

print "Program executing \n\tpid: %d, processName: %s" % (os.getpid(), processName)

r, w = os.pipe() # these are file descriptors, not file objects

pid = os.fork()

print "pid : %s" % pid

if pid:

# we are the parent

os.close(w) # use os.close() to close a file descriptor

r = os.fdopen(r) # turn r into a file object

print "parent: reading"

txt = r.read()

os.waitpid(pid, 0) # make sure the child process gets cleaned up

else:

# we are the child

processName = "child"

print "Program executing \n\tpid: %d, processName: %s" % (os.getpid(), processName)

os.close(r)

w = os.fdopen(w, 'w')

print "child: writing"

w.write("here's some text from the child")

w.close()

print "child: closing"

sys.exit(0)

print "parent: got it; text =", txt

print "Program executing \n\tpid: %d, processName: %s" % (os.getpid(), processName)