Snippet for getting the default gateway on Linux

get_default_gateway_linux.py

#Snippet for getting the default gateway on Linux
#No dependencies beyond Python stdlib

import socket, struct

def get_default_gateway_linux():
    """Read the default gateway directly from /proc."""
    with open("/proc/net/route") as fh:
        for line in fh:
            fields = line.strip().split()
            if fields[1] != '00000000' or not int(fields[3], 16) & 2:
                continue

            return socket.inet_ntoa(struct.pack("<L", int(fields[2], 16)))

if __name__ == '__main__':
    print get_default_gateway_linux()

I don't have a big-endian machine to test on, so I'm not sure whether the endianness is dependent on your processor architecture, but if it is, replace the < in struct.pack('<L', ... with = so the code will use the machine's native endianness.

Thanks, I like your solution. It works with Python3, just change the print statement to a print function instead.