Add Gracefully Exit A Script With Trap as a Unix TIL

unix/gracefully-exit-a-script-with-trap.md

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+# Gracefully Exit A Script With Trap
+
+With `trap` you can intercept signals that would cause your script to exit and
+then inject some additional behavior. Perhaps you want to make sure the script
+cleans up after itself before it exists.
+
+During this script's execution, it creates a file in the filesystem. It would
+be nice to make sure that no matter path this script ends up down that it will
+clean up after itself as it exits. We set up a `trap` that looks for the `EXIT`
+signal to do this.
+
+```bash
+# Set up trap
+trap 'echo "Cleaning up temp files"; rm -f *.tmp' EXIT
+
+# Create temporary file
+echo "test data" > work.tmp
+
+# Do some work
+cat work.tmp
+
+# Trap will clean up on exit
+```
+
+Whatever is in quotes is what the trap will execute when it is triggered. The
+following one or more signals are what the trap listens for, in this case
+`EXIT`.
+
+[source](https://tldp.org/LDP/Bash-Beginners-Guide/html/sect_12_02.html)