preg_match for a specific pattern in a url

I would like to use preg_match in PHP to test the format of a URL. The URL looks like this:

<a href='http://~dead host~/vypdye57f25o' rel='nofollow' target='blank'>part-2</a> 

Code (markup):

well honestly I have no idea of preg_match creating but my goal is

a pattern start with <a href= contain word ~dead host~ end with </a>

I try string contain in php native function but unfortunately it was not smart so I think preg_match is the only choice.

 

Here is a basic PHP script I came up with that uses preg_match to see if the url matches the regular expression: "<a href=.*~dead host~.*</a>"
which basically means start with "<a href" contain "~dead host~" somewhere in the middle, and end with "</a>". I hope that is what you are looking for. You just need to set the $url variable to the url are are trying to check.

$url = "<a href='http://~dead host~/vypdye57f25o' rel='nofollow' target='blank'>part-2</a>";
$pattern = "@<a href=.*~dead host~.*</a>@";

if(preg_match($pattern, $url))
    print "Valid Format";
else
    print "Invalid Format";

Code (markup):