Setting the environment variable PERL_SIGNALS to "unsafe" works, but it must be set before the script is started. What you could do is put something like this at the top of your script: 
unless ($ENV {PERL_SIGNALS} && $ENV {PERL_SIGNALS} eq "unsafe") {
    $ENV {PERL_SIGNALS} = "unsafe";
    exec $0, @ARGV;
}

[download]
This will look at your environment, and if the environment variable isn't set to the value you want, it sets it, and execs itself. Now your alarm ought to work (assuming your Perl is 5.8.1 or older).

In reply to Re: Losing control of large regular expressions by Anonymous Monk
in thread Losing control of large regular expressions by scottb

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.