создать нового пользователя или обновить информацию о новом пользователе по умолчанию (create a new user or update default new user information)
Статус выхода (Exit)
The useradd command exits with the following values:
0
success
1
can't update password file
2
invalid command syntax
3
invalid argument to option
4
UID already in use (and no -o)
6
specified group doesn't exist
9
username already in use
10
can't update group file
12
can't create home directory
14
can't update SELinux user mapping
