[Tutor] why "ifconfig" is alway running?

[Evert Rol]

>>> #!/usr/bin/env python
>>> import datetime
>>> import subprocess
>>> import sys
>>> import os
>>> import signal
>>> from time import sleep
>>> 
>>> def host_run(cmd, secs=10):
>>>    print("running %s" % cmd)
>>>    timeout = datetime.timedelta(seconds=secs)
>>>    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
>>> stderr=subprocess.STDOUT, shell=True)
>>>    start = datetime.datetime.now()
>>>    while ( proc.poll() is None and (datetime.datetime.now() - start)
>>> < timeout): #not timed out
>>>        print proc.stdout.readline() #TODO timestamp?
>>>        print "hello,i'm here"
>>>        sleep(1)
>>>    if 0 == proc.poll():
>>>        print("'%s' is program exited" %cmd)
>>>    else:
>>>        try:
>>>            os.kill(proc.pid, signal.SIGINT)
>>>           print "Process timeout: '%s'" % cmd
>>>        except OSError:
>>>            pass
>>> #cmd="ping 128.114.122.2"
>>> cmd="ssh root at 10.0.0.1"
>>> host_run(cmd,10)
>>> 
>>> if cmd="ssh root at 10.0.0.1"
>>> it never print "hello i'm here" , how can i handle this issue, and I
>>> find my script cant process the "timeout" to kill it.
>>> if cmd="ping 128.114.122.2", no this issue.
>> 
>> Have you tried running these two commands from the command line?
>> Spot the difference: ssh is waiting for input (a password. And if passwordless, it may still not produce output to stdout), while ping just continues to produce output.
>> Then look at the line
>>    print proc.stdout.readline()
>> Will that ever read a full line for the ssh command? Probably not, while for ping it will.
>> 
> 
> it's a test, actually, I can't access 10.0.0.1, i just want to kill it
> if *no responding" in 10 second, but it doesn't kill it. I don't know
> why.
> my script is to run a cmd, if more than 10 sec, kill it
> can you show me where is wrong, thanks in advance

But you never said where the script gets stuck. That would be a very important first step for debugging.

And if I run this script, I get the following:
"
$> python bla.py 
running ssh root at 10.0.0.1
ssh: connect to host 10.0.0.1 port 22: Connection refused

hello,i'm here
"
So seems to work for me.
thus, what is the result of 
$> ssh root at 10.0.0.1 
for you?

  Evert


>> So my guess is, your script gets stuck at that line.
>> But if you ctrl-C to stop the script, you should see where your program gets stuck. You didn't say where it got stuck, that would have helped.
>> 
>> Good luck,
>> 
>>  Evert
>> 
>> 
>>> On Sun, Dec 19, 2010 at 4:57 PM, Alan Gauld <alan.gauld at btinternet.com> wrote:
>>>> 
>>>> "lei yang" <yanglei.fage at gmail.com> wrote
>>>> 
>>>> 
>>>> def runForAWhile(cmd, secs=10):
>>>>   print("running %s" % cmd)
>>>>   timeout = datetime.timedelta(seconds=secs)
>>>>   print timeout
>>>>   proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
>>>> stderr=subprocess.STDOUT, shell=True)
>>>>   status = proc.poll()
>>>> 
>>>> You are still only checking status once outside the while loop.
>>>> 
>>>>   start = datetime.datetime.now()
>>>>   while (status is None and (datetime.datetime.now() - start) <
>>>> timeout): #not timed out
>>>>       print proc.stdout.readline() #TODO timestamp?
>>>>       #print status
>>>>       #print datetime.datetime.now() - start
>>>> 
>>>> 
>>>>> I see that "status" always "!=0“  why  program  is NOT exited
>>>> 
>>>> 
>>>> --
>>>> Alan Gauld
>>>> Author of the Learn to Program web site
>>>> http://www.alan-g.me.uk/
>>>> 
>>>> 
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>> 
>>