The print command isn't executed because it's not in the regex. The first portion of the s/// (between the first two //'s) is a regex; the other portion could be considered a string. So you need to place the (?{ print $1 }) at the end of the regex part, like so: 
$str = "(<ref links=\" cit314-1 cit314-2 cit314-3 cit314-4 cit314-5\"/
+>)";

if( $str =~ s/<ref links="(.*?)"(.*?)\/>(?{ print $1, "\n" })/<ref lin
+ks="$1"$2><\/ref>/ ){
    print "Match was found." . "\n";
}
print $str . "\n";

[download]
Notice I also didn't escape the quotes -- this isn't necessary and, I think, it makes things look a little messier.

elusion : http://matt.diephouse.com

In reply to Re: regex (?{CODE}) question by elusion
in thread regex (?{CODE}) question by ctgIT

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.