User Management

Managing Users and Groups

Oreon Linux uses standard Linux tools for managing user accounts and groups. This allows for fine-grained control over permissions and access.

These commands typically require superuser privileges (use sudo).

User Management

Adding Users

To add a new user:

sudo useradd <username>

This creates the user account but it's initially locked. You need to set a password:

sudo passwd <username>

You will be prompted to enter and confirm the new password.

Common options for useradd:

• -m: Create the user's home directory (often the default behavior).
• -G <group1>,<group2>: Add the user to supplementary groups.
• -s <shell>: Specify the user's login shell (e.g., /bin/bash).
• -c "<Comment/Full Name>": Add a descriptive comment.

Example: Add user 'jane' to the 'developers' group with a comment:

sudo useradd -m -G developers -c "Jane Doe" jane
sudo passwd jane

Modifying Users

To modify an existing user account, use usermod. Common options include:

• -l <new_username>: Change the username.
• -g <primary_group>: Change the primary group.
• -G <group1>,<group2>: Set the list of supplementary groups (overwrites existing list).
• -aG <group_to_add>: Add the user to a supplementary group (appends to existing list).
• -s <shell>: Change the login shell.
• -L: Lock the user account.
• -U: Unlock the user account.

Example: Add user 'john' to the 'testers' group without removing existing groups:

sudo usermod -aG testers john

Deleting Users

To delete a user account:

sudo userdel <username>

To also remove the user's home directory and mail spool:

sudo userdel -r <username>

Group Management

Adding Groups

To create a new group:

sudo groupadd <groupname>

Modifying Groups

To change a group's name or GID (Group ID):

sudo groupmod -n <new_groupname> <old_groupname>

sudo groupmod -g <new_gid> <groupname>

Deleting Groups

To delete a group:

sudo groupdel <groupname>

Note: You generally cannot delete the primary group of an existing user.

Checking User and Group Information

To see your own user and group IDs:

id

To see user/group IDs for another user:

id <username>

To list the groups a user belongs to:

groups <username>

If no username is specified, it shows the groups for the current user.

User and group information is stored in files like /etc/passwd, /etc/shadow, /etc/group, and /etc/gshadow. While you can view these files, it's recommended to use the provided command-line tools for modifications.