Linux Administration - Accounts

[top] User accounts

Files 

/etc/passwd					- Password file
/etc/shadow					- Shadow password file

/etc/skel 					- Skeleton home directory templates	

/etc/profile, /etc/profile.d 			- global, login settings
/etc/bashrc, /etc/bash.bashrc 			- global, non-login settings

~/.bash_login, ~/.profile, ~/.bash_profile 	- user, login settings
~/.bash_logout				 	- user, logout settings
~/.bashrc 					- user, non-login settings

~/.inputrc					- user, keyboard settings

Commands 
useradd -d /home/[user_name] -m /etc/skel [user_name]
Add a user, creating his home directory and using the specified skel template.

usermod [user_name]
Modify existing user account.

userdel [user_name]
Delete user account.

passwd [user_name]
Change user's password.

chage [user_name]
Set user account expiration policy.

pwconv
Converts regular passwords to shadow passwords.

pwunconv
Converts shadow passwords back to regular passwords.

pwck
Checks integrity of /etc/passwd and /etc/shadow files.


[top] Group accounts

Files 

/etc/group		- Group file
/etc/gshadow		- Shadow group file

Commands 
groupadd [group_name]
Add group.

groupmod [group_name]
Modify group.

groupdel [group_name]
Delete group.

gpasswd [group_name]
Change group's password.

grpconv
Converts regular group passwords to shadow passwords.

grpunconv
Converts shadow group passwords back to regular group passwords.

grpck
Checks integrity of /etc/group and /etc/gshadow files.