$ enable -n defer; enable -f ./defer defer
$ trap -- INT
$ defer 'echo "hello world"' INT
$ defer -p INT
trap -- 'echo "hello world"' SIGINT
$ defer 'rm -f -- "$tmp"; printf "Cleanup done on %s\\n" "$tmp"' INT
$ defer -p INT
trap -- 'rm -f -- "$tmp"; printf "Cleanup done on %s\\n" "$tmp"
echo "hello world"' SIGINT
trap_prepend () { trap "$1
$(trap -P "$2")" "$2"; }
$ trap_prepend 'echo "Hello World!"' SIGINT
$ trap -p SIGINT
trap -- 'echo "Hello World!"
' SIGINT
$ trap_prepend 'rm -f -- "$tmp"; printf "Cleanup done on %s\n" "$tmp"' SIGINT
$ trap -p SIGINT
trap -- 'rm -f -- "$tmp"; printf "Cleanup done on %s\n" "$tmp"
echo "Hello World!"' SIGINT
