Use the CGI module
Use the CGI module. The problem that you have here is that you have to interface with the URL that's being passed to the script. One way to do that with CGI is
#!/usr/bin/perl -wT

use strict;
use CGI;
my $q = new CGI;

$pet = $q->param{ "animal" };

# Instead of 
# print "Content-type: text/html\n\n";
# use...
print $q->header( "text/html" );
print <<STUFF;

<html>
<head></head>
<body>
<center>

<form><input type="text" value="$pet" size="25"></form>
</body>
</html>

STUFF

[download]
The code $q->param{ "animal" }; finds the part of the URL passed to the script that contains the value of the form element "animal".
It's suggested that you use strict and the -T switch to check for tainted variables perlsec.
Run a Super Search for plenty of CGI info or check out the O'Reilly book CGI Programming with Perl
Rich36
There's more than one way to screw it up...
Updated with $q->header( "text/html: ); - thanks jeffa

In reply to Re: passing a variable from a link by Rich36
in thread passing a variable from a link by ginocapelli

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.