php preg_match to validate twitter handler

Question

Hi, Please tell me the pattern to validate a twitter handler using preg_match

Thanks

Answer 1

Twitter allows you to use letters, numbers, and '_', so

preg_match("/[a-z0-9_]+/i", username)

for a case-insensitive search with at least one character.

Answer 2

I think greg forgot the "@" that indicates the beginning of a twitter handler:

preg_match("/\@[a-z0-9_]+/i", $username);