Observe the following code:

 
#!/usr/bin/perl 

use strict; 
use HTML::LinkExtor;

my $html = <<EOF
<p>
    <a href="http://example1.com/">
        Example 1
    </a>
</p>

<p>
    <a href="http://example2.com/">
        Example 2
    </a>
</p>

<p>
    <a href="http://example3.com/">
        Example 3
    </a>
</p>

EOF
;
# Print them out

print "Here's all links:\n";
my @return  = find_my_links($html); 
print join("\n", @return), "\n";

print "Here's all links #2:\n";
my @return2 = find_my_links($html); 
print join("\n", @return2), "\n";



sub find_my_links { 

    my $str = shift; 
    my @links = (); 

    sub callback {
         my($tag, %attr) = @_;     
         return if $tag ne 'a';  # we only look closer at <a ...>
         my $link =  $attr{href}; 
        push(@links, $link);         
    }

    my $p = HTML::LinkExtor->new(\&callback);
    $p->parse($str);
    undef $p; 
    undef $str;
    return @links; 

}
[download]

In this barebones example, I want to grab the links in found in $str, and I encapsulate all my stuff in the find_my_links() subroutine.

Easy enough, and it works! Once. If I call the parse() method twice, the second time will return an empty list. Why?

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.