meta parsing problems

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

This snippet below isn't parsing meta tags the way it should. This is using LWP::Simple and the source code (which works) is in $content.

This needs to match ANY meta tag in the format shown in the script, and yes I know I shouldn't do it this way but that's the question isn't on using a different module, it's how to fix this problem. Problem is, meta tags aren't always on the same line, they can all be bunched together like a paragraph and that's where this must be messing up.

Nothing prints at all, when I use an array that's split on /n it doesn't work because not all meta tags are separated by new lines.

Where is the error in this, anyone know?

my @meta_results;
my $count = 0;

my @lines = split /\n/, $content;

while(<$content>)
{
  if (/<meta name=\"(.+?)\" content=\"(.+?)\">/gi)
  {
    $count++;
    $meta_results[$count] = "$1::$2";
  }
}

foreach (@meta_results) {print "$_\n";}
[download]

Comment on meta parsing problems Download Code

Replies are listed 'Best First'.
Re: meta parsing problems by Joost (Canon) on May 23, 2004 at 21:59 UTC
Quick & dirty solution: `while($content =~ /<meta\s+name=\"(.+?)\"\s+content=\"(.+?)\">/ig) +{ $count++; $meta_results[$count] = "$1::$2"; }` [download] It won't work with reversed attributes, single quoted attributes, and lots more... Use a module. I hear HTML::Parser is nice. Good luck Updated: thought $content really was a filehandle, but it wasn't. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l]
Re: meta parsing problems by exussum0 (Vicar) on May 23, 2004 at 20:27 UTC
You treat $content as a string. 5th line, you treat it like a filehandle, reading it line by line. You can't have it both ways. What if name and content were switched in positions. XML allows that. regexp's dont' work easily on context free languages. Humma la beeba la seeba la booba la Humma la beeba la seeba la bop	[reply]
Re: Re: meta parsing problems by Anonymous Monk on May 23, 2004 at 21:09 UTC
So what's the solution for the string problem? The array didn't work so I was forced to use a scalar, which obviously doesn't work either. I'm prepared for the reversed meta tags, I thought about that already but that's to be worked on after the meta tags work the first time around with this. thanks	[reply]
Re: meta parsing problems by Ctrl-z (Friar) on May 23, 2004 at 22:54 UTC
this isnt fool proof, but it'll probably do what you want... `foreach( $content =~ m#<meta (.?)>#sgoi ) { my $name = $1 if( $_ =~ m#name\s?=\s?["'](.?)["']#sgoi); my $cont = $1 if( $_ =~ m#content\s?=\s?["'](.*?)["']#sgoi); }` [download] time was, I could move my arms like a bird and...	[reply] [d/l]
Re^2: meta parsing problems by Anonymous Monk on Oct 20, 2007 at 11:33 UTC
Eventhough the thread's a bit old... There are problems with this approach. You should rellay consider using HTML::TreeBuilder, it's as easy as `use HTML::TreeBuilder; my $tree = HTML::TreeBuilder->new()->parse($data); for my $tag ($tree->look_down( _tag => "meta")) { $kWords{$tag->attr("name")} = $tag->attr("content"); }` [download] The above code takes care of spaces/linebreaks &s.o. And its fast and widely used. Just my 5cents. FJ	[reply] [d/l]
Re: meta parsing problems by mrpeabody (Friar) on May 24, 2004 at 23:37 UTC
This needs to match ANY meta tag in the format shown in the script, and yes I know I shouldn't do it this way but that's the question isn't on using a different module, it's how to fix this problem. Problem is, meta tags aren't always on the same line, they can all be bunched together like a paragraph and that's where this must be messing up. You don't want to hear about using a module, but then you complain about having to solve precisely the nontrivial problem that the module is designed to solve. "I'm having trouble mowing my lawn with these scissors. I don't want to use my lawnmower, so don't suggest that. How can I make these scissors work better?" You can either use the module and be done with a robust solution in ten minutes, or spend hours re-implementing the module and have a weak, brittle solution. Your choice.	[reply]