TestOut Linux Pro Practice Test 2026 – Complete Exam Prep Guide

When changing passwords for user accounts, one important requirement is that the password must be encrypted in the shadow file. In Linux systems, user passwords are often stored in a secure manner in a file called the shadow file, usually located at /etc/shadow. This file contains hashed passwords rather than the plain text versions to enhance security and protect user credentials from unauthorized access.

Password encryption helps to ensure that even if someone gains access to the shadow file, they cannot easily decipher the actual passwords. The hashing process involves transforming the password into a fixed-size string of characters, which is not reversible. Consequently, when a user logs in, the entered password is hashed and then compared to the stored hash in the shadow file. This is a fundamental practice of secure password management in Linux systems.

In contrast, having the username included in the command, a specific length for passwords, and restrictions on using numbers do not constitute mandatory requirements for changing passwords across all Linux distributions. The actual requirements can vary based on system settings, security policies, or the version of the Linux operating system in use.