As Molt says, parsing HTML with regexes is very fragile and you'd be better off using a real HTML parser to do this.

Here's a simple example using HTML::Parser.

use warnings;
use strict;
use HTML::Parser;

my $html = do { local $/; <> };

my @text;
my $p = HTML::Parser->new(text_h=> [\@text, 'dtext']);

$p->parse($html);

print map { $_->[0] } @text;
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"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg

HTML::TokeParser::Simple. The function you want is in the docs.

 my $html = join '', @webpage_lines;
 my $p = HTML::TokeParser::Simple->new( \$html );

 while ( my $token = $p->get_token ) {
     # This prints all text in an HTML doc (i.e., it strips the HTML)
     next if ! $token->is_text;
     print $token->return_text;
 }
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Cheers,
Ovid

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Look at a HTML Parser, either HTML::Parser itself or (even more simply) HTML::TokeParser. Your regexps are fragile, they will break.. try feeding <img src="this.gif" alt="<<THIS>>"> into it, watch it fall over screaming.

If you want a nice full description of HTML parsing, if this is going to be something you're doing a lot of, then peer into 'Perl and LWP' by O'Reilly.

Hi Molt,

Thanks for the reply but as I stated in my first post I don't really mind that your line of code would leave me with >"> in my output right now - as long as there are no valid tags left that could alter formatting, run scripts etc. - I'm working on learning this from the ground up :)

But the book sounds good - I'll look into it for future reference :)

Thanks!,
Neil

Depending on how much inaccuracy you can tolerate, you can get a reasonable facsimile of stripping all HTML by doing:

$page =~ s/<[^<>]*>//g; # Note the added < inside []
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assuming the entire page content is in $page. A line by line approach like that in your original post will fail on tags that span multiple lines. The regexp above will break if you have unbalanced < or > inside of html tags, but may be good enough for your use.

i suppose I should suggest this:

use HTML::TagFilter;
my $tf = new HTML::TagFilter;
...
$tf->allow_tags({});
my $text = $tf->filter($html);
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which does exactly the same as the other parser-based solutions, but by way of a subclass that hides much of the unpleasantness. It mght be worth a look if you think you'll want to strip html selectively later on, but otherwise i'd stick with one of the more direct methods described above.

One of the simplest ways to go about this would just be to replace "<" with "&lt;", and ">" with "&gt;".

This way, you don't have to worry about balancing the tag beginnings and endings, and it won't break a message using the angle brackets to mean "less than" and "greater than".

Update: I probably got the idea from the forum at Joel On Software. Depending on how this is being used and your users, may also want to have a note telling the user that they can't use HTML to format their submission.

Another Update: Changed the second angle bracket to the closing angle bracket, changed the entities to match.