Centos8 User & Groups Operations

Burada yayınlanan komutlar Linux tabanlı Centos için geçerlidir.

List all users on your machine:
more /etc/passwd
awk -F ':' '{print $ 1}' /etc/passwd

To display the entire User count:
cat /etc/passwd | wc -l

Creating a user account:
adduser username

Deleting a user account:
#userdel username

Switching a user account:
su username

Changing a user's password:
passwd username

Changing a user's group membership:
usermod -g new_group username

***This command provides a new group name in which you want the specified user to join the group.

Changing a user's home directory:
usermod -d /new/home/directory username

***This command allows you to change the home directory of the specified user.

View user information and settings:
id username

Terminate all active sessions for a user:
pkill -KILL -u username

Resetting a user's password:
passwd -d username

***This command deletes the specified user's password and requires the user to create a new password the next time they log in.

Set a user's account expiration date:
chage -E "2027-xx-xx" username

Show "wheel" group users
getent group wheel

To grant root privileges to the user:
usermod -aG wheel username

Requiring a user's password:
chage -d 0 username

To create a group:
sudo groupadd grupadi

To delete a group:
sudo groupdel grupadi

List all groups in the system:
cat /etc/group

List a user's groups:
groups username

View details of a specific group:
getent group grupadi

To change a group name:
sudo groupmod -n yeni_grup_adi eski_grup_adi

Listing Group Members:
members grupadi

Change a user's name or group:
usermod -l new_username old_username

Changing the user's UID:
usermod -u 1001 username

Changing the user's group:
usermod -g developers username

Change a user's password lifetime:
chage -M 90 username

View user's account activity and recent login information:
last username

Set user sign-in restrictions:
chage username

Set user's password policies:
passwd -d -u username

Temporarily disable user's account:
usermod -L username

Reactivate the user's account:
usermod -U username

Changing the user's group:
usermod -g groupname username

***This command changes the home group of the specified user.

Change a user's additional groups:
usermod -aG groupname username

Adding user "user1" to the "testgroup" group:
sudo gpasswd -a user1 testgroup

To remove user "user1" from group "testgroup":
sudo gpasswd -d user1 testgroup

Locking the user's account:
usermod -L username

Opening the user's account:
usermod -U username

Show message on user's next session:
echo "message" > /etc/issue

Showing messages to all users throughout the system:
wall "message"

List logged in users
w

Bulk adding users:
newusers home/path/users.txt

***user.txt columns content:
Kullanıcı adı
Parola
Kullanıcı ID'si (UID)
Grup ID'si (GID)
Ev dizini
Kabuk (Shell)

***user.txt columns content:
test1:Sifre:1001:1001:/home/test1:/bin/bash
test2:Sifre:1002:1002:/home/test2:/bin/bash
test3:Sifre:1003:1003:/home/test3:/bin/bash
test4:Sifre:1004:1004:/home/test4:/bin/bash
test5:Sifre:1005:1005:/home/test5:/bin/bash

View the last date users signed in:
lastlog