#!/usr/bin/env perl
#
# danielbowling424@msn.com
# http://swagg.cc
#
# Copyright 2019 Daniel Bowling, Mount Rainier, Maryland, USA
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED
#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

use strict;
use warnings;

sub unix_mac {
    $_ =~ tr/[A-F]/[a-f]/; # toggle case
    $_ =~ s/[\-\.:]//g; # strip out symbols
    $_ =~ s/\G[a-f0-9]{2}\K/:/g; # insert colons every 2 characters
    $_ =~ s/[:]$//; # strip off remainder colon
    return $_;
}

if (@ARGV) {
    @_ = @ARGV;
} elsif (not -t STDIN) {
    chomp (@_ = <STDIN>);
} else {
    print "USAGE: $0 <MAC ADDRESS(S)>\n" .
        "Fix up MAC from arguments or standard input if no argument given.\n";
    exit 64;
}

foreach (@_) {
    unix_mac($_);
    print "$_\n";
}