#!/usr/bin/perl use strict; use warnings; my $fileData = < 255.255.255.255.trivnet1: UDP, length 12 19:39:44.765572 IP 10.195.32.212.49152 > 239.0.82.11.trivnet1: UDP, length 12 19:39:45.202568 IP 10.195.32.96.61804 > 255.255.255.255.sentinelsrm: UDP, length 40 19:39:45.265116 IP 10.195.32.212.49152 > 255.255.255.255.trivnet1: UDP, length 12 19:39:45.265590 IP 10.195.32.212.49152 > 239.0.82.11.trivnet1: UDP, length 12 19:39:45.411153 IP 10.195.32.198.netbios-ns > 10.195.32.255.netbios-ns: NBT UDP PACKET(137): QUERY; REQUEST; BROADCAST 19:39:45.412136 IP 10.195.32.198.netbios-dgm > 10.195.32.255.netbios-dgm: NBT UDP PACKET(138) 19:39:45.620442 STP 802.1d, Config, Flags [none], bridge-id 8020.00:22:56:29:3a:00.8014, length 43 19:39:45.765086 IP 10.195.32.212.49152 > 255.255.255.255.trivnet1: UDP, length 12 FILE my @headRow = ('Time stamp', 'Source IP address', 'Destination IP address'); my $rowFormat = "%-17s %-22s %-22s\n"; open my $fIn, '<', \$fileData; printf $rowFormat, @headRow; while (<$fIn>) { my ($time, $from, $to) = /(.{8})\.\d+ IP ([\d.]+)\.\d+ > ([\d.]+)\./; next if ! defined $to; printf $rowFormat, $time, $from, $to; }