sleep repeat

#!/usr/bin/python2


import multiprocessing
import sys
import time
import os


def interact(pipe, stdin):
    readfd, writefd = pipe
    readfd.close()
    print "Enter seconds to wait"
    for line in stdin:
        seconds = float(line)
        print "Requesting additional %g seconds. Enter more if you like" \
            % seconds
        writefd.send(seconds)


def wait(pipe, interact_process):
    readfd, writefd = pipe
    writefd.close()
    time.sleep(4)
    while readfd.poll():
        seconds = readfd.recv()
        print "Waiting additional %g seconds" % seconds
        time.sleep(seconds)
    print "Killing child"
    interact_process.terminate()


def main():
    # use simplex connection between both processes to send additional
    # waiting time
    pipe = multiprocessing.Pipe(False)
    # duplicate stdin because multiprocessing will close the original fd
    # in the child
    stdinfd = os.dup(sys.stdin.fileno())
    stdin = os.fdopen(stdinfd, 'rt', 1)
    child = multiprocessing.Process(target=interact, args=(pipe, stdin))
    child.start()
    wait(pipe, child)
    child.join()


if __name__ == '__main__':
    main()