auto-linking an URL

[Tsukasa]

I am programming a PHP guestbook for some newbie training. 🙂

Now, what I thought to do was, in a "website" field, link what they typed there automatically when you later read the post. Easy enough, with the variables in a <a href> echo and all. There is one problem, though. If you do that, it links everything, so you just type dkhjfhg as a web and the script links the thing. 🙁

Since the "website" field is optional, and there is a pre-http:// already there, even if they leave it alone, it links too [url]http://,[/url] which is kind of lame 🙁 I thought I'd make the GB so that it detects if there is a proper URL typed, if it is, then link it. But if there is only a "http://" or even a blank field, the script shouldn't link it.

Alas, I have absolutely NO idea how to DO that :rolleyes:
Help is really appreciated, so I can get past this part and continue with more functions for the GB, which I plan to make my project of ascent in the PHP language. 😉

[theeper]

Extract the field from your table that has the URL in it.

Do an if statement to make sure there is at least something there.

Do a regex to validate the string and make sure it is a URL.

If the two above conditons are met, echo the entire <A HREF=> line, else don't echo anything.

[siwis]

look up the various string handlers like eregi() etc which look for specific string groups.

Once you've created your string expressions, you can run any url through it and return a true or false response.