User/Group management
GUI Tool
system-config-user
Add user account
useradd -c "full name" username
Add user account /w C Shell
useradd -s /bin/tcsh username
Add user account under a specify folder
useradd -c "full name" -d /home/accounting/username username
Add user name + group assignment
useradd -G groupname username
Add user /w password
useradd -p password username
Change user id
usermod -u UID username
Change user name
usermod -l newname oldname
Remove user account along with user’s directory and mailbox file
userdel -r username
Remove user’s directory
rm -rf /home/username
Modify user’s info
usermod -c "full name" username
Password change
passwd username
Password lock
passwd -l username
Password unlock
passwd -u username
Set password age for 90 days
chage -M 90 username
Set password never expire
chage -M -1 username
Set password to expire on specify date
chage -E 2012-01-01 username
Set warning 2 days prior to password expiration
chage -W 2 username
List password policy
chage -l username
Add a group
groupadd groupname
Add user to a group
usermod -G groupname username
Make the group assignment effective without logout
newgrp groupname
Change UID
usermod -u UID username
List user’s belong group
groups
Change group name
groupmod -n newname oldname
Change group ID
groupmod -g 1000 groupname
Show user’s ID
id username
Assign a user as group administrator
gpasswd -A username groupname
Assign a user to a group by adminstrator
gpasswd -a username groupname
Remove a group
groupdel groupname
