Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
$mac =~ s/(^|\.)([0-9a-f]?)(?=[0-9a-f])/$2 || 0/eg;

That solves the original problem. ybiC pointed out that another format mac addresses come in has groups of 4 characters, separated by :. The amended question was whether both formats can be handled together. The following does that:

$mac =~ s/[^0-9a-f]*([0-9a-f]?)([0-9a-f])/($1 || 0) . $2/eg;
In both cases the delimiter is gobbled by not being cached in a backref, and if it does not appear in even groups then a 0 will appear.

Danger alert. In the pair "05" the 0 gets replaced, so if you wanted to use this to insert anything other than 0 you would need to not just check the truth of $1, but rather it's length.


In reply to Simple RE answer by tilly
in thread One for the regexp fans by Odud

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!
  • 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, 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, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            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.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others having an uproarious good time at the Monastery: (7)
    As of 2015-03-28 17:55 GMT
    Find Nodes?
      Voting Booth?

      When putting a smiley right before a closing parenthesis, do you:

      Results (625 votes), past polls