Match Arabic/English Alphanumeric using Regex - php

Question

I would like to have a regular expression that matches:
Arabic letters.
List item
English alphanumeric.
3 Spaces maximum.
4 Underscores maximum.
Any order.
I tried varies solution but couldn't solve it.
Here is what i have now:
preg_match('#^([^\W_]*\s){0,3}[^\W_]*$#', $username)
The above expression allows:
3 spaces maximum
English alpanumerics
No underscore allowed

Answer 1

You can check if your Regex flavour supports this \p{Arabic} or \p{InArabic}.
Also experiment with mb_ereg_match() function: http://si2.php.net/manual/en/function.mb-ereg-match.php
If that doesn't work, there is no other option than explicitly writing all arabic characters into the expression. Messy, but does the work.
Since you are using php, you can first list all arabic characters into a string variable and then add that variable to regex, for the code manageability's sake.

Answer 2

I don't know about arabic characters, but the following regexp should match the others
([a-zA-Z0-9]{1,})\s{0,3}_{0,4}
This will match
(Alphanumeric)(0-3 spaces)(0-4 underscores)
If there are more than 4 underscores, the last ones will be omitted
If there are more than 3 spaces then the part after the 3 spaces will be ignored.
EDIT:
For arabic letters: First declare a string containing all arabic letters
so you'll have
$arabic='all_arabic_letters';
Then your regexp string will be
$regex='[' . $arabic . ']{1,}([a-zA-Z0-9]{1,})\s{0,3}_{0,4}';
And match it as follows:
preg_match($regex, $username);