[SOLVED] How to restrict user name fields

RE: www.joomlapolis.com/forum/153-professional-member-support/215798-how-to-restrict-user-name-fields#296740

Hello,

I came upon this topic when looking for the same solution.

I only want usernames to contain only letters (lowercase and uppercase) and numbers, not special charactes.

Is this still correct what I need to fill out in "Perl regular expression"? /[a-zA-Z0-9]*/

I'm just asking, because in the info tooltip it says:
only a+z + A+Z + digits: /^[0-9a-z]*$/i

So I'm wondering which one is the correct one? (In the tooltip, I also don't see capital A-Z even though it claims to be included for that code).

Thanks!

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Yes, that is correct. the "i" modifier makes it case insensitive.

So both are equally correct codes then?

Sorry about the replying to an old topic - I hadn't paid attention to how old it was.

Yes, you can use the "i" modifier or you can specify a-zA-Z to cover upper and lower case. See the below for REGEXP usage information.

www.regular-expressions.info/

In that case, I can keep the code I had put in.

Thanks for the information

Hello,

I come back to this topic because I noticed recently that new users are able to register a username with a space in it. Because my website is linked with Moodle, which doesn't allow spaces in usernames, I need to avoid this from happening.

I assumed that my settings were set so that only letters and numbers were allowed and nothing else, but apparently that is not the case. These are my settings for the "username" field:

Authorized input: Custom Perl regular expression
Perl regular expression: /[a-zA-Z0-9]*/

Should I change hte Perl regular expression to something else? Or should I change the authorized input to single a-z,A-Z,0-9,_ word?