Regex to match 'A HREF=', quoting RE replacements (was: Regex Question)

dsb has asked for the wisdom of the Perl Monks concerning the following question:

This is the situation. I am writing a text based web-browser(don't ask why...call it practice...I want to get to know the Perl extension modules better...This uses LWP, HTTP, and HTML modules) and the way I deal with links calls for a substition regex. I'm using Oreilly's homepage for testing. In dealing with the links I do a substitution on the resource:

while ( $src =~ m%<a href="([^"]+)"(?:.|\n)*?>([^>]+)</a>%g ) {
    $inf->{$i} = { 'url' => $1, 'res' => $2 };
    $s_text    = $2;
    $n_src  =~ s%$s_text%[$i $s_text]%;
    $i++;

}
[download]

This is just a possible method to keeping track of the links. The problem is that one of the links in the source for the page has a '+' in it. I get a "nested *?+" error when I run the script because of it. I would just escape it in the regex but the value is held in a scalar. I tried to substitute all +'s with an escaped plus but that didn't work. It just substitutes with another '+'(the backslash apparently doesn't show in the string).

I'm out of ideas with this one. Any help would be great.

Amel - f.k.a. - kel

2001-03-04 Edit by Corion : Changed title

Comment on Regex to match 'A HREF=', quoting RE replacements (was: Regex Question) Download Code

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Re: Regex Question by japhy (Canon) on Mar 03, 2001 at 00:57 UTC
Use the `\Q...\E` metacharacter-escape sequence. `$n_src =~ s/\Q$s_text\E/[$i $s_text]/;` [download] `japhy` -- Perl and Regex Hacker	[reply] [d/l]
Re: Regex Question by Anonymous Monk on Mar 03, 2001 at 01:09 UTC
I tried to substitute all +'s with an escaped plus but that didn't work. It just substitutes with another '+'(the backslash apparently doesn't show in the string). If this is the case, your substitution code probably looked something like `s/\+/\+/g` which is incorrect, you're escaping the + on the rhs not adding a backslash, you would need to do `s/\+/\\+/g`, but don't do that either, if you want to escape metacharacters use quotemeta() or \Q	[reply] [d/l] [select]