TestOut Linux Pro Practice Test 2025 – Complete Exam Prep Guide

Using a checksum to verify the integrity of a file involves calculating a hash value for the file and then comparing it to a previously known value. The method of using `md5sum` is one of the most common approaches to achieve this. When you run the command `md5sum [filename]`, it computes the MD5 hash of the specified file and outputs it. This hash serves as a unique fingerprint for the file's contents. If you have a known MD5 checksum that the file is supposed to match, you can easily verify the file's integrity by comparing the computed checksum with the known value. This process helps identify any alterations, corruptions, or tampering with the file.

In comparing the other options, `sha256sum [filename]` is also a legitimate method to check file integrity but uses the SHA-256 hashing algorithm, which produces a longer hash and is generally considered more secure than MD5. However, the question specifically notes `md5sum` as the correct choice, implying a preference or focus on that particular method. The commands `verify [filename]` and `checksum [filename]` are not standard commands used in Linux for calculating checksums, making them less appropriate for this context.