preg_match excluded characters

[tkm76]

Hi everybody!

 

I'm having a bit of a problem with preg_match. I've spent two days on this, tried dozens of ways, nothing worked. So I decided to join this forum. OK, my problem is in these lines of code:

 

if (!preg_match("/^[a-zA-Z0-9_\-\.]*$/", $username)){

echo "Username contains excluded characters!";

exit;

}

 

I'm making a registration form, and I want to allow following types of registration: "john_doe", "john-doe" and "john.doe". Besides "johndoe". Case sensitivity and numbers are also included. Everything other than that should be considered as excluded. I somehow managed to register two dummy records as it is. But after that it started giving me that echo message" Username contains excluded characters!" if i DON'T user those three special characters as well! And that shouldn't be a condition, but an option. How do I solve this problem? I would be grateful if someone would correct me in whatever I'm doing wrong. Thanks in advance!

 

T.K.M.

 

 

[johnny86]

Try:

if(!preg_match('#^[\w\.-]+$#i', $username))

{

echo 'illegal characters!';

}

[tkm76]

I just tested it. It works flawlessly.

Thank you!