1 Topic by cris

  • cris
  • Member
  • Offline
  • Registered: 2006-03-12
  • Posts: 23

Topic: Regular expression for usernames

I created a script to allow users to upload their images and i create a new folder on my server for every user.
i noticed that punbb allows users to register with names containing "forbidden" characters (!*#) and then i can't create a folder with those names, so i'd like to check usernames during registration so that they use only chars allowed by my (linux) hosting

any suggestion is appreciated, i know i have to use something like preg_match, but i don't know how...
thank you smile

  • From: Leuven, Belgium
  • Registered: 2005-06-14
  • Posts: 2,653

Re: Regular expression for usernames

You could try something like this:

<?php
if(strpos($username,'*') || strpos($username,'!') || strpos($username,'#'))
    {
    error("Your name contains invalid characters!");
    }
?>
  • Reines
  • Reines
  • Senior Member
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  • Registered: 2004-10-07
  • Posts: 304

Re: Regular expression for usernames

you could use something along the lines of:

function valid_username($username) {
    return preg_match('/[^a-zA-Z0-9]/', $username) == 0;
}

That will only allow alphanumeric characters.

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