TestOut Linux Pro Practice Test 2026 – Complete Exam Prep Guide

The command 'chmod' in Linux is used specifically to modify the permissions associated with a file or directory. This allows the user to control who can read, write, or execute a file based on the permissions assigned to it. Permissions in Linux are categorized into three types: read (r), write (w), and execute (x), and are assigned to three different classes of users: the owner of the file, the group associated with the file, and all other users.

When a system administrator or user wants to change these access rights, they use the 'chmod' command, following it with the appropriate symbolic (e.g., 'u+x' to add execute permission for the user) or numeric (e.g., '755' for specific permission settings) arguments. By doing so, they can ensure that files are secure and accessed appropriately as per the requirements of different use cases.

The other choices—modifying file contents, file ownership, or file name—are not functions of the 'chmod' command, as these require different commands such as 'nano' or 'vi' for editing content, 'chown' for changing ownership, and 'mv' for renaming files. Therefore, 'chmod' distinctly focuses on altering the permissions of