The bummer with what you have there, besides being long, is that it matches stuff if you've got the colons and the dashes intermingled in the same string, which is probably NOT what you want. Try this chunk of code out: 
#!/usr/bin/perl -w

use strict;

my $d = "[0-9A-Fa-f]";
my $dd = "$d$d";

while (<DATA>) {
        /($dd([:-])$dd(\2$dd){4})/o && print $1, "\n"
}

__END__
My MAC address is 00-00-00-00-00-00 over there,
and it's 00:00:00:00:00:00 over here, and
the date/time happens to be 2001-05-25-15:27.
Note that 00:00-00:00-00:00 isn't really valid.
Oh, and I have one address of DE:AD:BE:EF:21:12.

[download]
When I run it, I get the following output 
00-00-00-00-00-00
00:00:00:00:00:00
DE:AD:BE:EF:21:12

[download]
Note that it skipped the 4th sample line where the dashes 'n' colons are intermingled.

xoxo,
Andy 

%_=split/;/,".;;n;u;e;ot;t;her;c; ".   #   Andy Lester
'Perl ;@; a;a;j;m;er;y;t;p;n;d;s;o;'.  #   http://petdance.com
"hack";print map delete$_{$_},split//,q<   andy@petdance.com   >

In reply to Re: Regular Expression for MAC Address by petdance
in thread Regular Expression for MAC Address by marius

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.