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>

```

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.