Using Traps in Shell Scripts

This tutorial provides an overview of using traps in shell scripts, allowing you to handle signals and events gracefully.

1. Introduction to Traps

Traps in shell scripts are used to capture and respond to signals and other events during script execution. They help in handling unexpected conditions and ensuring script stability.

2. Basic Usage of Traps

Here's the basic syntax for using traps:

trap 'command' SIGNAL

Replace SIGNAL with the signal name or number you want to trap, and command with the action you want to perform when the signal is received.

3. Examples of Using Traps

Let's explore some examples to understand how traps work:

Example 1: Trap SIGINT

trap 'echo "Script interrupted"; exit' INT

This command traps the SIGINT signal (Ctrl+C) and executes the specified command when the script is interrupted.

Example 2: Trap SIGTERM

trap 'echo "Termination signal received"; cleanup_function' TERM

This command traps the SIGTERM signal and calls a cleanup function when the script is terminated.

4. Handling Errors with Traps

Traps are also useful for handling errors and exceptions in shell scripts. You can define traps to clean up resources, log errors, or gracefully exit the script.

5. Conclusion

Traps provide a powerful mechanism for handling signals and events in shell scripts, improving script robustness and reliability. By effectively using traps, you can ensure your scripts behave predictably in various conditions.