how to set timeout for os.popen

[Jugurtha Hadjar]

On 04/15/2018 12:01 PM, Ho Yeung Lee wrote:
> while 1:
> runner = os.popen("tracert -d www.hello.com")
> o=runner.read()
> print(o)
> runner.close()
> runner = os.popen("tracert -d www.hello.com")
> o=runner.read()
> print(o)
> runner.close()
> runner = os.popen("tracert -d www.hello.com")
> o=runner.read()
> print(o)
> runner.close()
>
>
> after running over 1 hour, it stop and not return in one of tracert
>
> how to set timeout and know that this is timeout?

import signal
import time
from contextlib import contextmanager

@contextmanager
def timeout(duration, handler):
     """Timeout after `duration` seconds."""
     signal.signal(signal.SIGALRM, handler)
     signal.alarm(duration)
     try:
         yield
     finally:
         signal.alarm(0)


def interrupt_handler(signum, frame):
     print('Interrupt handler saves the day')
     raise TimeoutError


# You can use that in many ways:

# At definition time:

@timeout(10, interrupt_handler)
def foo():
     print('Begin foo')
     while True:
         print('foo is printing')
         time.sleep(3)


# At use time, define foo normally:

def bar():
     print('Begin bar')
     while True:
         print('bar is printing')
         time.sleep(3)
with timeout(10, interrupt_handler):
     print('I am inside with, above bar')
     bar()