# coding=utf-8
import os


def myfork():
    """
    only support on Linux
    :return:
    """
    pid = os.fork()
    if pid == 0:
        print ("this is child %d" % pid)
    else:
        os.waitpid(pid,0)
        print ("this is parent %d" % pid)

if __name__ == '__main__':
    myfork()

