Solve exercises by writing Bash one-liners. The server actually runs your commands and checks whether the output is correct.
If you click on View Solutions, the correct commands other people entered are sorted by character count. So if you want, you can take the optional code golfing challenge.
I gained some knowledge from solving the challenges and looking at the solutions. Mostly you will use
This is for anything regarding the command line, in any operating system. All questions (including dumb ones), tips, and interesting programs/console applications you’ve found or made yourself are welcome. Linux / BSD / macOS / Windows CLI apps, questions or comments, we’re happy to take them all!