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trap Command: Run Code On Signals

trap runs code on signals. Cleanup. Error handling. Useful.

Here's the thing: trap runs code on exit. Use it for cleanup.

Basic trap​

trap 'echo "Exiting"' EXIT

My take: trap runs code on exit. Use it.

Cleanup​

temp_file="/tmp/temp_$$"
trap "rm -f $temp_file" EXIT

My take: trap cleans up. Use it.

Error Handling​

trap 'echo "Error on line $LINENO"' ERR

My take: trap handles errors. Use it.

Common Patterns​

Cleanup on Exit​

temp_file="/tmp/temp_$$"
trap "rm -f $temp_file" EXIT INT TERM

What's Next?​

Now that you understand trap, let's talk about Error Logging.

Personal note: trap seemed complex at first. Then I used it for cleanup. Now I use it always. It's useful. Learn it.