preg_replace background URL in CSS attribute

Question

I'm using file_get_contents() to get source code of a page but I fail in some websites that uses CSS like this:

background: url("/media/image")
background: url(/media/image)
background: url('/media/image')
// etc...

Now, I want to know how can I edit that CSS and add my website, so it will look like this:

background: url("http: //example.com/media/image")
background: url('http: //example.com/media/image')
background: url(http://example/media/image)
// etc...

. Here is my code:

$regex = "-(src\s*=\s*['\"])(((?!'|\"|http://|https://|//).)*)(['\"])-i"; 

I'm doing this on the src attribute of an HTML tag. I hope I'm helping

Answer 1

This $regex will replace the background: url(["|']?$URL["|']?) with ["|']?$img["|']?:

$homepage = file_get_contents('http://www.example.com/');
$img = "http://placehold.it/350x150";

$regex = '/(background: url\((["|\']?))(.+)(["|\']?\))/';
$replacement = "$1$img$4";
$homepage = preg_replace($regex, $replacement, $homepage);

echo $homepage;