#!/usr/bin/perl
#eth0      Link encap:Ethernet  HWaddr 00:20:18:8C:CF:38
#          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
#          RX packets:28996528 errors:146 dropped:225 overruns:0 frame:0
#          TX packets:17386158 errors:0 dropped:0 overruns:0 carrier:0
#          collisions:1188496 txqueuelen:100
#          RX bytes:2863396931 (2730.7 Mb)  TX bytes:1792216541 (1709.1 Mb)
#          Interrupt:10 Base address:0xf000

$iface = shift or die("usage: ifcfg <iface>\n");
open(IFCFG, "/sbin/ifconfig $iface |") or die("Where is ifconfig? : $!\n");
while(<IFCFG>) {
        if (/RX bytes:(\d+?)\s.+?TX bytes:(\d+)/) {
                print("$1\n$2\ninterface $iface\nunused\n");
        }
}