code for wordpress

Job ID: 35936816

Budget: £10 – £15 GBP

Php code for wordpress
I would like a simple code for wordpress website that add random 6 small letters/numbers to the end of the username when they register

for example if the user name is: karim
I would like the code to make it: karim-1kd567
the code must also check if the username exist then try another combination.

I will place the code myself on the website for privacy reasons.
Skills required
PHP, WordPress
Related categories: PHP Data Entry WordPress Word Copy Typing