Ubuntu Unleashed 2013 Edition: Covering 12.10 and 13.04, Eighth Edition

File Permissions

As you learned in Chapter 3, “On the Internet,” there are three types of permissions: read, write, and execute (r, w, x). For any file or directory, permissions are assigned to three categories: user, group, and other. This section focuses on group permissions. First, though, we want to highlight three commands used to change the group, user, or access permissions of a file or directory:

• chgrp—Changes the group ownership of a file or directory

• chown—Changes the owner of a file or directory

• chmod—Changes the access permissions of a file or directory

You can use these commands to reproduce organizational structures and permissions in the real world in your Ubuntu system (see the next section, “Managing Groups”). For example, ...