yunaimatsu

CRUD of users and groups

	User(user-)	Group(group-)
Create(-add)	useradd	groupadd
Read
Update(-mod)	usermod	groupmod
Delete(-del)	userdel	groupdel

users # Host - Users
groups # Which group does the user belong to?
whoami

CRUD of PASSWORD

Password itself

passwd,gpasswd

chpasswd

Password expiration period

chage

chsh

chsh -s <shell-name>
chsh -l

• High-level tools

  adduser

  deluser

###

id

id -u
id -g
id -G
id -n 
id -z

/etc/shadow

• Obsolete commands to convert/unconvert shadow files

  pwconv, pwunconv , grpconv, grpunconv exist in /bin but not used by users manually.

  pwck, grpck

  vipw, vigr exist in /bin but not used by users manually.

/etc/passwd

storing password hashes and password aging information.

HTTP server

htpasswd

htdigest

Aren’t used widely.

chfn

They create