Handling POSIX signals in bash using trap

Bash has a way of intercepting signals to perform actions. This is a nice way to have cleanup functions that can be executed before the program exists. Here are some examples in how you can setup a function that is capable of intercepting signals.

#!/bin/bash
# settting up the trap for the function 'cleanup'. The number 2 here refers to SIGINT signals.
trap cleanup 2
cleanup() {
  echo "Signal intercepted!"
}

sleep 60 &
wait $!

As you can imagine, you can specify multiple signals to be handled by the same function:

trap catch 2 15

You can also use the signal codes if you find that more legible:

trap catch SIGINT SIGTERM

Here is a list of some of the common signals: