I run a chatterbox on the allpoetry.com website. We allow formatting for *bold* to be turned bold, etc. We also have smilies, which are added first. The slashes turn out to be the biggest problems, since they're in images often.

So given this text:  go/to <img src='http://allpoetry.com:8080/images/smile/happy.gif'> /thx/ <img src='http://allpoetry.com:8080/images/smile/happy.gif'> silly *to*

Should return: g<em>to <img src='http://allpoetry.com:8080/images/smile/happy.gif'> </em>thx/ <img src='http://allpoetry.com:8080/images/smile/happy.gif'> silly <b>to</b>

Its rather key to NOT do anything to the last '/' - the problem is matching a '/' from the img instead.

As an additional complication, I'd like it to handle nested formatting as well (*/test/* = test)

I've been working on this for a *long* time, with many different iterations , but none seem that close. I'd like to avoid parsing it out into html tags and non-tags, but if anyone can suggest an efficient way to do that I'd love to hear it.

Here is what I have:

sub reg_fix {
    my $c = shift;
    
    $c =~ s#(<.*?>)|(/|\*|_|=)((?:<.*?>|[^\2])+?)\2\s?#
        if ($1) {$1} elsif ($2 eq '/') {'<em>' . reg_fix($3) . '</em> 
+'}
        elsif ($2 eq '*') {'<b>' . reg_fix($3) . '</b> '}
        elsif ($2 eq '_') {'<u>' . reg_fix($3) . '</u> '}#gemio;
    
    return $c;
}

$c = reg_fix($c);

[download]

Which now fails because in the second part: ((?:<.*?>|[^\2])+?)\2\s?#, if it DOESN'T find \2, will backtrack and dip inside the <.*?> tag, which is what I want to avoid. I thought of trying to use (\2|$) at the end, to see if we were at the end, but then it won't finish parsing the string for other matches. 

$c =~ s#((<.*?>)|(/|\*|_|=)((?:<.*?>|[^\2])+?)(\2|$)\s?)#
sub reg_fix {
    my $c = shift;
    print "Running check on '$c'\n";
    $c =~ s#((<.*?>)|(/|\*|_|=)((?:<.*?>|[^\2])+?)(\2|$)\s?)#
    
    if (!$5) {$1}
    elsif ($2) {$1} 
    elsif ($3 eq '/') {'<em>' . reg_fix($4) . '</em> '}
    elsif ($3 eq '*') {'<b>' . reg_fix($4) . '</b> '}
    elsif ($3 eq '_') {'<u>' . reg_fix($4) . '</u> '}#gemio;
    return $c;
}

[download]

Any ideas, great and powerful perl monks? Thanks :)

In reply to match *bold* formatting, but avoid html by Anonymous Monk

Title:
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