TestOut Linux Pro Practice Test 2026 - Free Linux Pro Practice Questions and Study Guide

When a directory's permissions are set to 755, it means that the owner has full access to that directory, which includes read, write, and execute permissions. In the notation of Unix-like file systems, the numbers represent permissions in a three-digit octal system.

The first digit, '7', corresponds to the owner's permissions. In binary, this is represented as '111', which indicates that the owner can perform all actions: read (4), write (2), and execute (1). The total of these values gives 7 (4 + 2 + 1), confirming that the owner can indeed read, write, and execute within that directory.

The subsequent digits in '755' specify the permissions for the group and others, respectively. In this case, '5' for both the group and others means that they have read and execute permissions, but not write permissions. This distinction is important for understanding how access is controlled within the directory.

In summary, the owner has complete control over the directory with permissions set to 755, allowing them to read, modify, and traverse the directory effectively.