preg_match_all question

[Chris Bruce <chris@xxxxxxxxxxxx>]

Hello,

I am using the following to do link replacing:

preg_match_all("/<\s*a\s+[^>]*href\s*=\s*[\"']?([^\"' >]+)[\"' 
>]/isU",$file[$x],$matches);

It works great for all but 'https' links. I am not that versed in 
regular expressions. Would anyone know what I need to put in there so 
that it will match on https links?

Thanks,

Chris