6.4. Additional Resources

6.4.1. Installed Documentation

The following resources are installed in the course of a typical Red Hat Enterprise Linux installation and can help you learn more about the subject matter discussed in this chapter.

• User Manager Help menu entry — Learn how to manage user accounts and groups.

• passwd(5) man page — Learn more about the file format information for the /etc/passwd file.

• group(5) man page — Learn more about the file format information for the /etc/group file.

• shadow(5) man page — Learn more about the file format information for the /etc/shadow file.

• useradd(8) man page — Learn how to create or update user accounts.

• userdel(8) man page — Learn how to delete user accounts.

• usermod(8) man page — Learn how to modify user accounts.

• passwd(1) man page — Learn how to update a user's password.

• chpasswd(8) man page — Learn how to update many users' passwords at one time.

• chage(1) man page — Learn how to change user password aging information.

• chfn(1) man page — Learn how to change a user's GECOS (finger) information.

• chsh(1) man page — Learn how to change a user's login shell.

• groupadd(8) man page — Learn how to create a new group.

• groupdel(8) man page — Learn how to delete a group.

• groupmod(8) man page — Learn how to modify a group.

• gpasswd(1) man page — Learn how to administer the /etc/group and /etc/gshadow files.

• grpck(1) man page — Learn how to verify the integrity of the /etc/group and /etc/gshadow files.

• chgrp(1) man page — Learn how to change group-level ownership.

• chmod(1) man page — Learn how to change file access permissions.

• chown(1) man page — Learn how to change file owner and group.

6.4.2. Useful Websites

• https://www.bergen.org/ATC/Course/InfoTech/passwords.html — A good example of a document conveying information about password security to an organization's users.

• https://www.crypticide.org/users/alecm/ — Homepage of the author of one of the most popular password-cracking programs (Crack). You can download Crack from this page and see how many of your users have weak passwords.

• https://www.linuxpowered.com/html/editorials/file.html — a good overview of Linux file permissions.

6.4.3. Related Books

The following books discuss various issues related to account and resource management, and are good resources for Red Hat Enterprise Linux system administrators.

• The Red Hat Enterprise Linux Security Guide; Red Hat, Inc. — Provides an overview of the security-related aspects of user accounts, namely choosing strong passwords.

• The Red Hat Enterprise Linux Reference Guide; Red Hat, Inc. — Contains detailed information on the users and groups present in Red Hat Enterprise Linux.

• The Red Hat Enterprise Linux System Administration Guide; Red Hat, Inc. — Includes a chapter on user and group configuration.

• Linux Administration Handbook by Evi Nemeth, Garth Snyder, and Trent R. Hein; Prentice Hall — Provides a chapter on user account maintenance, a section on security as it relates to user account files, and a section on file attributes and permissions.