For the parser types among us, there are likely more suitable options to be had though. 
use strict;
use warnings;
use HTML::TokeParser::Simple;

my %xlat = (
    Smiley => ':)',
    Wink => ';)',
);

my $p = HTML::TokeParser::Simple->new( \*DATA );
while ( my $t = $p->get_token ) {
    if(
        $t->is_start_tag('img')
        and my $r = $xlat{$t->return_attr->{alt}}
    ) {
        print $r;
    }
    else {
        print $t->as_is;
    }
}
__END__
<body>
<a href="wink.html">
   <img border="0" src="/images/wink.gif" alt="Wink">
</a>
<a href="smile.html">
   <img border="0" src="/images/smiley.gif" alt="Smiley">
</a>
</body>

[download]
Note this doesn't require XHTML.

Makeshifts last the longest.

In reply to Re^2: Why doesn't non-greediness work? (HTML::TokeParser::Simple) by Aristotle
in thread Why doesn't non-greediness work? by kiat

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