Small lookup for user management commands in Linux
- To know which users exist:
cat /etc/passwd | grep -i home - Delete a user:
userdel <username> - Add a user:
useradd -m <username>(the "-m" flag creates the home directory) - Set the user's password:
passwd <username> - Assign a user to a group:
usermod -a -G <groupname> <username>
(make the user re-login to activate the changes)
(for a user to be able to "su" to another one, it has to be in the group "wheel")
- View to which groups a user was assigned:
groups <username> - Remove a group from a user:
usermod -G <all_groups_the_user_is_supposed_to_have> <username>
Here I practically reassign to the user only the groups listed and the rest gets deleted.
(make the user re-login to activate the changes)
- Change the owner of a file:
chown <newowner> <filename> - Change the assigned group of a file:
chgrp <newgroup> <filename> - Create a group:
groupadd <newgroup>
Now you can assign files and users to the new group.
- Delete a group:
groupdel <groupname>