Here is how to use HTML::Parser to do the job (your) regex doesn't: 

#!/usr/bin/perl -w
package Filter;
use strict;
use base 'HTML::Parser';
my ($filter, %ok_tags);
my @ok_tags = qw ( i b );
@ok_tags{@ok_tags} = @ok_tags; 
sub start {
    my ($self, $tag, $attr, $attrseq, $origtext) = @_;
    $filter .= exists $ok_tags{$tag} ? $origtext : 'x';
}
sub text {
    my ($self, $text) = @_;
    $filter .= $text;
}
sub comment {
    my ($self, $comment) = @_;
    $filter .= $comment;
}
sub end {
    my ($self, $tag, $origtext) = @_; 
    $filter .= $ok_tags{$tag} ? $origtext : 'x';
}

my $html = join '', <DATA>;
my $parser = new Filter;
$parser->parse($html);
$parser->eof;
print $filter;

__DATA__
<html>
<head>
  <title>Foo</title>
</head>
<body>
  <B>This regex is broken</b>
  <b>It will cope with this</b>
  <b >But not this< /b>
  <i>told you</i>ts<b>roken</B>
</body>
</html>

[download]

Before you lay that on your teacher make sure you understand how the hash slice lookup table and the V2 interface to HTML::Parser works :-)

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

In reply to Re: Perl with XML by tachyon
in thread Perl with XML by Anonymous Monk

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