Here is what you need to know to survive (and thrive) in Shell01. Unlike traditional scripting exercises, 42’s Shell01 forbids the use of loops ( for , while , etc.) in several key exercises. Why? Because the Unix philosophy states that text manipulation should be done via filters .

Many beginners try basename or complex string manipulation. Solution: Use find , sed , or basename with parameter expansion.

find . -type f -name "*.sh" -exec basename {} .sh \; Key lesson: Read the find man page until you understand -exec and {} \; . Prompt: Count all files and directories in the current directory and all subdirectories.

If you have just finished Shell00 (where you learned to create files, manage permissions, and use ls ), Shell01 will feel like a sudden leap from "using a computer" to "thinking like a developer."