通过命令管道，在进程之间进行通信的简单例子

import os


if __name__ == "__main__":
    named_pipe = "my_pipe"

    if not os.path.exists(named_pipe):
        os.mkfifo(named_pipe)

    def write_message(input_pipe, message):
        fd = os.open(input_pipe, os.O_WRONLY)
        os.write(fd, (message +  str(os.getpid())))
        os.close(fd)
    write_message(named_pipe, "from write_pipe...")

import os

if __name__ == "__main__":
    named_pipe = "my_pipe"
    def read_message(input_pipe):
        fd = os.open(input_pipe, os.O_RDONLY)
        message = ("I pid [%d] received a message => %s" %(os.getpid(), os.read(fd, 22)))
        os.close(fd)
        return message
    print read_message(named_pipe)