Linux - User/Group

Commands

Create user:

useradd {user} -u {uid} -G {groups} -d {home} -s {shell}
# Ex:
#  useradd lako -u 500 -G docker -d /home/lkone -s /bin/bash

Create group and user:

groupadd -g {gid} {group}
useradd -u {gid} -g {gid} {name}

# Ex:
#  groupadd -g 500 lako
#  useradd -u 500 -g 500 lako

Add user into a group:

usermod -a -G {group} {user}
# Ex: usermod -a -G docker lako

Change user password:

echo "{password}" | passwd --stdin {user}
echo '{user}:{password}' | chpasswd

# Ex:
#  echo "@pass" | passwd --stdin lako
#  echo 'lako:@pass' | chpasswd

Force password change to next connection:

chage -d 0 {user}
# Ex: chage -d 0 lako

Files

Important files:

path	description
/etc/passwd	Contain all users info
/etc/group	Contain all groups info
/etc/shadow	Contain all passwords info