Please check and limit username input length
If an admin/reseller/client adds a new shell user there seems to be no limit on username lenght. This is very annoying and confusing if the resulting username is longer than 32 chars because this seems to be the limit on most linux systems.
In /var/log/ispconfig/cron.log the following error is visible: useradd: invalid user name 'username_longer_than_32_chars'
.. and it does not get created in the system.
... but in ISPConfig WebUi the user is still visible.
Also annoying is the fact that the username gets prefixed with the admins, resellers or clients username - but this is not visible when creating a new user and thus does not make the calculation of username lenght easier.
I would advice to length limit all fields, where usernames can be created to perhaps 12 chars. So a combination of prefix and username could not exceed 24 chars. Which is fairly sufficient i think.
And i would advice to use another prefix for shell users than the username of the creating account. The client id or somtehing more generic should be better and could even easier be set to a fixed length.
Regards, Matthias