#!/usr/bin/perl

use strict;

my $if = $ARGV[0] || mrtg_die();

open(F, "</proc/net/dev") || mrtg_die();
my @LINES = <F>;
close(F);

foreach (grep(/\s+$if\:/, @LINES)) {
    /\s+$if\:(\s*\d*){1}/;
    my $recv = $1;
        $recv =~ s/\s+//g;

    /\s+$if\:(\s*\d*){9}/;
    my $sent = $1;
        $sent =~ s/\s+//g;

    print "$recv\n$sent\n0\n0\n";
}

sub mrtg_die() {
    print "0\n0\n0\n0\n";
}