--- /dev/null
+#!/usr/bin/perl -w
+
+use strict;
+use HTML::Parser ();
+
+HTML::Parser->new(start_h => [ \&start_lc, "tokenpos, text" ],
+ end_h => [ sub { print lc shift }, "text" ],
+ default_h => [ sub { print shift }, "text" ],
+ )
+ ->parse_file(shift) || die "Can't open file: $!\n";
+
+sub start_lc {
+ my($tpos, $text) = @_;
+ for (my $i = 0; $i < @$tpos; $i += 2) {
+ next if $i && ($i/2) % 2 == 0; # skip attribute values
+ $_ = lc $_ for substr($text, $tpos->[$i], $tpos->[$i+1]);
+ }
+ print $text;
+}
+