#!/usr/bin/perl -w
use strict;

while(<DATA>) {
    if (!/^default/){next};
    my @stuff = split /\s+/;
    print $stuff[1];

}

1;

__DATA__
Kernel IP routing table
Destination     Gateway     Genmask         Flags MSS Window irtt Iface
255.255.255.255 0.0.0.0     255.255.255.255 UH    40  0      0    wlan0
192.168.1.0     0.0.0.0     255.255.255.0   U     40  0      0    wlan0
127.0.0.0       0.0.0.0     255.0.0.0       U     40  0      0    lo
default         192.168.1.1 0.0.0.0         UG    40  0      0    wlan0