Extract entire url content using Regex

Question

Okay, I am using (PHP) file_get_contents to read some websites, these sites have only one link for facebook... after I get the entire site I will like to find the complete Url for facebook

So in some part there will be:

<a href="http://facebook.com/username" >

I wanna get http://facebook.com/username, I mean from the first (") to the last ("). Username is variable... could be username.somethingelse and I could have some attributes before or after "href".

Just in case i am not being very clear:

<a href="http://facebook.com/username" >  //I want http://facebook.com/username
<a href="http://www.facebook.com/username" >  //I want http://www.facebook.com/username
<a class="value" href="http://facebook.com/username. some" attr="value" >  //I want http://facebook.com/username. some

or all example above, could be with singles quotes

<a href='http://facebook.com/username' > //I want http://facebook.com/username

Thanks to all

score 3 · Accepted Answer · answered Jul 14 '11 at 15:10

3

Don't use regex on HTML. It's a shotgun that'll blow off your leg at some point. Use DOM instead:

$dom = new DOMDocument;
$dom->loadHTML(...);
$xp = new DOMXPath($dom);

$a_tags = $xp->query("//a");
foreach($a_tags as $a) {
   echo $a->getAttribute('href');
}

answered Jul 14 '11 at 15:10

Marc B

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I wanted to provide a good resources explaining why you shouldn't use Regexp for the OP read. But I couldn't find the one I was thinking of. Any chance you have a good resource, Marc? – rzetterberg Jul 14 '11 at 15:12
1

This is the canonical answer when html+regex comes up on this site: http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454 – Marc B Jul 14 '11 at 15:18
Well the true is that I am using DOM, to get part of the document where I know the link of facebook will be, but in that part I will get bewtween 1 to 6 links, how do I get just the one that have facebook – Richard Pérez Jul 14 '11 at 15:18
@richard: `$xp->query("//a[contains(@href,'facebook')]");` – Marc B Jul 14 '11 at 15:22
@Marc it gave me this ... but I want just http://facebook.com/username.something – Richard Pérez Jul 14 '11 at 15:36
1

You still need the `$a->getAttribute()` portion to extract JUST the ``'s href attribute. – Marc B Jul 14 '11 at 15:40

score 1 · Answer 2 · answered Jul 14 '11 at 15:12

I would suggest using DOMDocument for this very purpose rather than using regex. Here is a quick code sample for your case:

$dom = new DOMDocument();
$dom->loadHTML($content);

// To hold all your links...
$links = array();

$hrefTags = $dom->getElementsByTagName("a");
    foreach ($hrefTags as $hrefTag)
       $links[] = $hrefTag->getAttribute("href");

print_r($links); // dump all links

Extract entire url content using Regex

2 Answers2