Add third_party/pexpect

third_party/pexpect/tests/platform_checks/check.py

+#!/usr/bin/env python
+import signal
+import os
+import time
+import pty
+
+def signal_handler (signum, frame):
+    print 'Signal handler called with signal:', signum
+    print 'signal.SIGCHLD=', signal.SIGKILL
+
+# First thing we do is set up a handler for SIGCHLD.
+signal.signal (signal.SIGCHLD, signal.SIG_IGN)
+
+print 'PART 1 -- Test signal handling with empty pipe.'
+# Create a child process for us to kill.
+try:
+    pid, fd = pty.fork()
+except Exception as e:
+    print str(e)
+
+if pid == 0:
+#    os.write (sys.stdout.fileno(), 'This is a test.\n This is a test.')
+    time.sleep(10000)
+
+print 'Sending SIGKILL to child pid:', pid
+os.kill (pid, signal.SIGKILL)
+
+# SIGCHLD should interrupt sleep.
+# Note that this is a race.
+# It is possible that the signal handler will get called
+# before we try to sleep, but this has not happened yet.
+# But in that case we can only tell by order of printed output.
+print 'Entering sleep...'
+try:
+    time.sleep(10)
+except:
+    print 'sleep was interrupted by signal.'
+
+# Just for fun let's see if the process is alive.
+try:
+    os.kill(pid, 0)
+    print 'Child is alive. This is ambiguous because it may be a Zombie.'
+except OSError as e:
+    print 'Child appears to be dead.'
+
+print 'PART 2 -- Test signal handling with full pipe.'
+# Create a child process for us to kill.
+try:
+    pid, fd = pty.fork()
+except Exception as e:
+    print str(e)
+
+if pid == 0:
+    os.write (sys.stdout.fileno(), 'This is a test.\n This is a test.')
+    time.sleep(10000)
+
+print 'Sending SIGKILL to child pid:', pid
+os.kill (pid, signal.SIGKILL)
+
+# SIGCHLD should interrupt sleep.
+# Note that this is a race.
+# It is possible that the signal handler will get called
+# before we try to sleep, but this has not happened yet.
+# But in that case we can only tell by order of printed output.
+print 'Entering sleep...'
+try:
+    time.sleep(10)
+except:
+    print 'sleep was interrupted by signal.'
+
+# Just for fun let's see if the process is alive.
+try:
+    os.kill(pid, 0)
+    print 'Child is alive. This is ambiguous because it may be a Zombie.'
+except OSError as e:
+    print 'Child appears to be dead.'
+