usermod command in Linux with Examples

usermod command or modify user is a command in Linux that is used to change the properties of a user in Linux through the command line. After creating a user we have to sometimes change their attributes like password or login directory etc. so in order to do that we use the Usermod command. The information of a user is stored in the following files: 

• /etc/passwd
• /etc/group
• /etc/shadow
• /etc/login.defs
• /etc/gshadow
• /etc/login.defs

When we execute usermod command in terminal the command make the changes in these files itself. 

Note: usermod command needs to be executed only as a root user. 

Working with usermod command

1. To add a comment for a user 

sudo usermod -c "This is test user" test_user

This will add a comment about the user or a short description related to the user. 

2. To change the home directory of a user 

sudo usermod -d /home/manav test_user

This will change the home directory of the user to /home/manav. 

3. To change the expiry date of a user 

sudo usermod -e 2020-05-29 test_user

This will change the expiration date of account "test_user" 

4. To change the group of a user 

sudo usermod -g manav test_user

This command will now change the group of test user from test_user to manav 

5. To change user login name 

sudo usermod -l test_account test_user

This will now change the login name of the user "test_user". 

6. To lock a user 

sudo usermod -L test_user

This will lock the "test_user" account and will display a! sign in shadow file before the username 

7. To unlock a user 

sudo usermod -U test_user

This will unlock the "test_user" which was locked by the previous command 

8. To set an unencrypted password for the user 

sudo usermod -p test_password test_user

This will set the password "test_password" in the unencrypted form for the user "test_user" 

9. To create a shell for the user 

sudo usermod -s /bin/sh test_user

This command will now create a shell for the user "test_user" from /bin/sh 

10. To change the user id of a user 

sudo usermod -u 1234 test_user

This command will change the user id of "test_user" to 1234