php preg替换条件

Question

hello I want to replace this code of css:

background:url("/media/image.png")

and I have a url

$url3 ="http://example.com";

here is the code I'm using :

preg_replace('~url\(("|\')?/?(.*?)(?:\1)?\)~', 'url($1'.$url3.'/$2$1)', background:url("/media/image.png");

the output of this code gives me :

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

and this is what I want , but my problem is I want to add some conditions to my regex for example if the url have // or http or https at start then ignore it don't add http://example.com/ to it.

this is the regex I have tried :

~url\(("|\')?/?(.*?)(?:\1)?\)~(((?!'|\"|http://|https://|//).)*)(['\"])-i 

but it didn't work ..

Answer 1

Since you are hard-coding the replacement I think it would be easiest to just do another check:

if (false === preg_match("~url\((\"|')(//|https?://)~", $string)) {
    // do replacement
}

Also note that the argument to url() in CSS does not require quoting (" or ').