Permissions and User management

Change group ownership

The code below will associate a folder to a specific group. This is helpful when you are associated with more than one groups and the default group assigned to a file you created is not for the intended group.

chgrp -R new_group path/to/folder
# R for recursive

File permissions using chmod

The code below will give read, write, and execute permissions to all the group members. A minus sign after g e.g. g-wx will take away write and execute permissions.

chmod -R g+rwx path/to_folder
# R is for recursive

Add a new user

The command below will add a new user to a Linux system, create their home directory at /home/newuser and set the default shell to /bin/bash.

sudo useradd -m -s /bin/bash newuser

The command below set the password for the new user.

sudo passwd newuser

Delete a user

The command below will delete a user without deleting their home directory.

sudo userdel newuser

To delete the home directory as well.

sudo userdel --remove newuser

Login as another user

To login as a newly created user

sudo -u newuser bash

Add an existing user to a group

sudo usermod -a -G groupname newuser