[SOLVED] Simple eregi question

[pianoman993]

How do I validate a $username string by checking if it contains charactors such as ?!-+= etc... ? I'm not sure if your supposed to use eregi or preg_match or what. If someone knows the answer please post your code below. Thanks!

[effigy]

What are the valid characters for a user name?

[pianoman993]

Alphanumeric values and hyphens.

There can be no hyphen at the beginning of the string.

[effigy]

What about min and max lengths? No underscores?

 

<?php
if (!preg_match('/\A(?!-)[-a-z0-9]+\z/', $string)) {
	echo 'Invalid';
}
?>

[pianoman993]

As for length I have a if(!substr($username,6,20)) {} condition. Underscores are not permitted. Thanks for your help.

[effigy]

substr does not enforce limits. You can consolidate this by exchanging the + with {6,20}.

[pianoman993]

Great, i will do that thanks. Oh and one more thing, how do I make it so that a hyphen can not be the last character of the $username string?

[effigy]

/\A(?!-)[-a-z0-9]{6,20}(?<!-)\z/

[pianoman993]

Quick question, I've been trying to figure out a way to use this preg_match function

 

if (!preg_match('/\A(?!-|_)[-_a-zA-Z0-9]{6,20}|(?<!-|_)\z/', $username))

 

but add an additional rule allowing only ONE space in the $username string. I fear the solution is aggravatingly simple

[effigy]

if (substr_count($username, ' ') >= 2
|| !preg_match('/\A(?![-_ ])[-\w ]{6,20}(?<![-_ ])\z/', $username)
) { ... }

[pianoman993]

Thanks man