suppress scapy warning message when importing the module

Question

I\'m writing a small script, that gathers some information using scapy and then returns some xml code, that I\'ll pass on to the xmlrpc interface of metasploit. I\'d like it tha

Answer 1

I think this is the correct way.

>>> import sys
>>> sys.stderr = None            # suppress stderr
>>> from scapy.all import *
>>> sys.stderr = sys.__stderr__  # restore stderr
>>> print("other errors can be shown", file=sys.stderr)
other errors can be shown
>>> 

Answer 2

You can get rid of warnings by scapy by adding:

logging.getLogger("scapy.runtime").setLevel(logging.ERROR)

before importing Scapy. This will suppress all messages that have a lower level of seriousness than error messages.

---

for example:

import logging
logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
from scapy.all import *
...

Answer 3

I think perhaps the python3 version of scapy prints a message from a different logger or at a high level. Here's some code I've used to suppress output on module import.

from contextlib import contextmanager

# It looks like redirect_stderr will be part of Python 3.5 as follows:
# from contextlib import redirect_stderr
# Perhaps if you're looking at this code and 3.5 is out, this function could be
# removed.
@contextmanager
def redirect_stderr(new_target):
    """
    A context manager to temporarily redirect stderr. Example use:
    with open(os.devnull, 'w') as f:
        with redirect_stderr(f):
            # stderr redirected to os.devnull. No annoying import messages
            # printed on module import
            from scapy.all import *
    # stderr restored
    """
    import sys
    old_target, sys.stderr = sys.stderr, new_target # replace sys.stdout
    try:
        yield new_target # run some code with the replaced stdout
    finally:
        sys.stderr = old_target # restore to the previous value


# Don't print the annoying warning message that occurs on import
with open(os.devnull, 'w') as errf:
    with redirect_stderr(errf):
        from scapy.all import sr, ICMP, IP, traceroute

Answer 4

With Python3, redefining sys.stderr to None threw an exception AttributeError: 'NoneType' object has no attribute 'write'. Instead, defining it to os.devnull does the job:

import os
import sys
sys.stderr = os.devnull # suppress stderr
from scapy.all import *
sys.stderr = sys.__stderr__ # restore stderr