Finding a url within a lot of text

[franzy_pan]

Hi all,

 

I'm just wondering if there is a way to locate a url written as HTML e.g. <a href="http://www.abcd.com/">Link</a> within a descriptive text description.  I only need the bit from the first " to the last " to allow me to change the url.

 

I can't figure out how to search for it whilst ensuring that I have the URL in its entirety.

 

Example text description:

 

<p>Win two smiley faces.</p><br />

Click here: <a href="http://www.abcd.com/">Link</a>

 

Any assistance or help would be greatfully recieved - thank you.

 

Franzy Pan ??? ???

[thebadbad]

You can use RegEx (preg_replace):

 

<?php
$str = 'bla bla <a href="http://oldurl.com/">link text</a> bla bla.';
$pattern = '|(?<=href=").*?(?=")|s';
$replacement = 'http://newurl.com/';
$str = preg_replace($pattern, $replacement, $str);
echo $str;
?>

 

For the search, I'm using a positive lookbehind (?<=string) which means the URL we're looking for (the following greedy .*? part) must be preceded by href=". Then I'm using a positive lookahead (?=string) which means the URL match will end at the first double quote encountered. The trick about lookbehinds and lookaheads is, that those parts aren't matched, which means that we can replace the match (= the whole URL only) with the new URL. Further reading: http://www.regular-expressions.info/lookaround.html