regex URL prepend with filename

Matt_Kindig

Hi everyone,

I've been trying to figure this out for two days. I've exhaustively searched the web and this forum and can't seem to figure out what I'm doing wrong.

I want to prepend all links from a particular domain (foo.com) with a link to my script, such that the link becomes a GET argument to my script. I only want this to do for that particular domain, and leave other domains alone. Here's what I have so far:

$search='@<a([^>]+?)href="(.+?)foo.com\/(.+?)"(.*?)>(.+?)<\/a>@si';
$replace='<a$1href="myscript.php?fp=$2foo.com/$3"$4>$5</a>';
$out=preg_replace($search,$replace,$page_to_parse);

Strangely enough, this does the replacement for all links except those originating from foo.com! Any help is greatly appreciated.

EDIT: I escaped the /'s after foo.com and in the </a> in my post, but the board stripped them out.

Thanks, Matt

paulnaj

Hi Matt,

Not sure If I can work out a full solution but couldn't you just restrict the search/replace operation to ...

<?php
$search = '@href="([a-zA-Z0-9:./]+)foo.com([^"]+)"@si'; 
$replace = 'href="myscript.php?fp=$1foo.com$2'; 
$out = preg_replace($search, $replace, $page_to_parse);
?>

That might work and it's a whole lot simpler ...

Paul 🙂

Matt_Kindig

Thanks! That solved the first problem but now a second problem has arisen. The string that will be matched by my pattern will have special regex characters in it. If it was in the replace pattern, I know I could use preg_quote to escape them out (with preg_replace_callback), but I'm not sure what to do when the special regex chars appear in the search string. Any ideas? Thanks.

paulnaj

Hi Matt,

Which regex characters do you mean? I can't quite see which are going to crop up in a web domain.

Matt_Kindig

The string from the foo.com contains $_GET data of its own, which I am using as a string. So it contains ?,&,.,+, and maybe a few more I haven't encountered yet.

paulnaj

Ok, just so I really understand your problem ...

Suppose we've got somewhere in the search text ...

href="www.foo.com?action=go&id=1"

... say. After the replacement, you're going to have ...

href="myscript.php?fp=www.foo.com?action=go&id=1"

When you get to myscript.php, you'll have ...

$_GET = array(
'fp' => 'www.foo.com?action=go'
'id' => '1'
);

Is that what you were intending?

Paul.

Matt_Kindig

This is exactly what I was intending. I can then use the $_GET vars for later processing in myscript.

$_GET = array(
'fp' => 'www.foo.com?action=go'
'id' => '1'
);

Any other ideas? Thanks so much for your help so far.

Matt