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#!/usr/bin/env python
import signal
import os
import time
import pty
import sys
import fcntl
import tty
GLOBAL_SIGCHLD_RECEIVED = 0
def nonblock (fd):
# if O_NDELAY is set read() returns 0 (ambiguous with EOF).
# if O_NONBLOCK is set read() returns -1 and sets errno to EAGAIN
original_flags = fcntl.fcntl (fd, fcntl.F_GETFL, 0)
flags = original_flags | os.O_NONBLOCK
fcntl.fcntl(fd, fcntl.F_SETFL, flags)
return original_flags
def signal_handler (signum, frame):
print '<HANDLER>'
global GLOBAL_SIGCHLD_RECEIVED
status = os.waitpid (-1, os.WNOHANG)
if status[0] == 0:
print 'No process for waitpid:', status
else:
print 'Status:', status
print 'WIFEXITED(status):', os.WIFEXITED(status[1])
print 'WEXITSTATUS(status):', os.WEXITSTATUS(status[1])
GLOBAL_SIGCHLD_RECEIVED = 1
def main ():
signal.signal (signal.SIGCHLD, signal_handler)
pid, fd = pty.fork()
if pid == 0:
os.write (sys.stdout.fileno(), 'This is a test.\nThis is a test.')
time.sleep(10000)
nonblock (fd)
tty.setraw(fd) #STDIN_FILENO)
print 'Sending SIGKILL to child pid:', pid
time.sleep(2)
os.kill (pid, signal.SIGKILL)
print 'Entering to sleep...'
try:
time.sleep(2)
except:
print 'Sleep interrupted'
try:
os.kill(pid, 0)
print '\tChild is alive. This is ambiguous because it may be a Zombie.'
except OSError as e:
print '\tChild appears to be dead.'
# print str(e)
print
print 'Reading from master fd:', os.read (fd, 1000)
if __name__ == '__main__':
main ()
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