Summary  
Programs return numeric exit codes to indicate success (usually zero) or specific errors (nonzero), and you can check these codes in code to control flow and implement error handling.

General domain of usage  
Shell scripting for automation and process control

A hands-on, beginner-friendly course to master the essentials of Bash scripting and command-line operations. Learn to navigate files, manage variables, handle input/output, and implement robust error handling—all through engaging explanations and real-world challenges.

Learn the foundational Bash commands for navigating the filesystem, listing files, and manipulating directories. Build confidence in using the terminal to interact with your computer.

Understand how to use variables in Bash scripts, including setting, referencing, and exporting environment variables for use by other programs.

Master the techniques for handling input and output in Bash, including redirection, pipes, and command substitution.

Learn how Bash uses exit codes to signal success or failure, and how to handle errors gracefully in scripts.

Understanding Exit Codes