$ cat /etc/passwd
$ cat /etc/group
$ cat /etc/default/useradd
$ cat /etc/login.defs
$ ls -a /etc/skel
$ less /etc/profile
===== Commands =====
* ''useradd'', ''usermod'', ''userdel''
* ''groupadd'', ''groupmod'', ''groupdel''
* ''passwd''
* ''newusers''
* ''chage''
===== User account creation =====
Afterwards, check:
$ grep username /etc/passwd
$ grep username /etc/group
$ ls /home