The password is the one line in data.txt that occurs exactly once among thousands of duplicated lines — sort groups identical lines together, and uniq -u prints only the ones with no duplicate.

Platform: OverTheWire Bandit

Category: Linux Fundamentals

Level: 8 → 9

Difficulty: Beginner

Technique: sort + uniq -u

Challenge description

Level 8 hands you a file where almost every line of text shows up more than once. Somewhere in there is exactly one line that appears only a single time — that line is the password.

"Level Goal: The password for the next level is stored in the file data.txt and is the only line of text that occurs only once."

Step 1 — Understand why uniq alone won't work

uniq only collapses consecutive duplicate lines — it has no effect on a file where duplicates are scattered throughout rather than grouped together.…