[Tutor] Telnetlib

[Danny Yoo]

> > Also, when you set the telnet debug level, all debug messages go by
> > default to sys.stdout. Is there a way to redirect to a file? I can't
> > find this in the documentation. Perl's Telnet module allows to do this


Hi Llazarre,

Yes, there's a way of redirecting standard error.  One way is to
temporarily set 'sys.stderr' out to another file, like this:

###
>>> sys.stderr = open("/home/dyoo/redirected_stderr.txt", "w")
>>> 1/0
>>>
###

Notice that no error pops up here, even though we did something bad in
dividing by zero.  When we open up that file, we'll see our missing
output:

###
>>> sys.stderr.close()
>>> f = open("/home/dyoo/redirected_stderr.txt")
>>> f.read()
'Traceback (most recent call last):\n  File "<stdin>", line 1, in
?\nZeroDivisionError: integer division or modulo by zero\n'
###


It's not a good thing to leave 'sys.stderr' hanging in a script, so we
often save the old sys.stderr, temporarily redirect it, and then set it
back once we're done.



Hope this makes sense!