User and Group Configuration

User Manager allows you to view, modify, add, and delete local users and groups. To use User Manager, you must be running the X Window System, have root privileges, and have the redhat-config-users RPM package installed. To start User Manager from the desktop, go to the Main Menu Button (on the Panel) > System Settings > Users & Groups or type redhat-config-users at a shell prompt (for example, in an XTerm or a GNOME terminal).

Figure 7-1: User Manager

To view a list of all local users on the system, click the Users tab. To view a list of all local groups on the system, click the Groups tab. If you need to find a specific user or group, type the first few letters of the name in the Filter by field. Press Enter or click the Apply filter button. The filtered list will be displayed. To sort the users or groups, click on the column name. The users or groups will be sorted by the value of that column.

Red Hat Linux reserves user IDs above 500 for system users. By default, User Manager does not display system users. To view all users, including the system users, uncheck Preferences > Filter system users and groups from the pull-down menu.

Adding a New User

To add a new user, click the New User button. A window as shown in Figure 7-2 will appear. Type the username and full name for the new user in the appropriate fields. Type the user’s password in the Password and Confirm Password fields. The password must be at least six characters.

Figure 7-2: New User

Tip

The longer the user’s password, the more difficult it is for someone else to guess it and log in to the user’s account without permission. It is also recommended that the password not be based on a word and that the password be a combination of letters, numbers, and special characters.

Select a login shell. If you are not sure which shell to select, accept the default value of /bin/bash. The default home directory is /home/username. You can change the home directory that is created for the user, or you can choose not to create the home directory by unselecting Create home directory.

Red Hat Linux uses a user private group (UPG) scheme. The UPG scheme does not add or change anything in the standard UNIX way of handling groups; it simply offers a new convention. Whenever you create a new user, by default, a unique group with the same name as the user is created. If you do not want to create this group, unselect Create a private group for the user.

To specify a user ID for the user, select Specify user ID manually. If the option is not selected, the next available user ID starting with number 500 will be assigned to the new user. Red Hat Linux reserves user IDs above 500 for system users.

Click OK to create the user.

To configure more advanced user properties such as password expiration, modify the user’s properties after adding the user. Refer to the “Modifying User Properties” section of this chapter for more information. To add the user to more user groups, click the User tab, select the user, and click Properties. In the User Properties window, select the Groups tab. Select the groups that you want the user to be a member of, select the primary group for the user, and click OK.

Modifying User Properties

To view the properties of an existing user, click the Users tab, select the user from the user list, and click Properties from the button menu (or choose File > Properties from the pull-down menu). A window similar to the one shown in Figure 7-3 will appear.

Figure 7-3: User Properties

The User Properties window is divided into tabbed pages.

User Data

Basic user information configured when you added the user. Use this tab to change the user’s full name, password, home directory, and/or login shell.

Account Info

Select Enable account expiration if you want the account to expire on a certain date. Enter the date in the provided fields. Select User account is locked to lock the user account so that the user can not log in to the system.

Password Info

This tab shows the date that the user last changed his or her password. To force the user to change his or her password after a certain number of days, select Enable password expiration. You can also set the number of days before the user is allowed to change the password, the number of days before the user is warned to change the password, and days before the account becomes inactive.

Groups

Select the groups that you want the user to be a member of and the user’s primary group.

Adding a New Group

To add a new user group, click the New Group button. A window similar to the one shown in Figure 7-4 will appear. Type the name of the new group to create. To specify a group ID for the new group, select Specify group ID manually and select the GID. Red Hat Linux reserves group IDs lower than 500 for system groups. Click OK to create the group. The new group will appear in the group list.

Figure 7-4: New Group

To add users to the group, see the next section.

Modifying Group Properties

To view the properties of an existing group, select the group from the group list and click Properties from the button menu (or choose File > Properties from the pull-down menu). A window similar to the one shown in Figure 7-5 will appear.

Figure 7-5: Group properties

The Group Users tab displays which users are members of the group. Select additional users to add them to the group, and unselect users to remove from the group. Click OK or Apply to modify the users in the group.