bash defer function - just like go's defer()

defer.sh

function _run_deferred() {
  local _depth="$BASHPID.${#FUNCNAME[@]}"
  [[ "$_depth" != "$_deferred_depth" ]] && return
  local opt=$-
  set +e
  for (( i=${#_deferred[@]} - 1; i >= 0; i-- )); do
    eval "${_deferred[i]}"
  done
  [[ "$opt" == *e* ]] && set -e
}
function _defer() {
  _deferred_depth="$BASHPID.${#FUNCNAME[@]}"
  _deferred+=( "$(printf '%q ' "$@")" )
}
# This has to be an alias so that the `trap ... RETURN` runs appropriately.
shopt -s expand_aliases
alias defer='declare -a _deferred; declare _deferred_depth; trap _run_deferred EXIT RETURN; _defer'

example.sh

function foo1() { echo foo1; }
function foo2() { defer echo foo2; foo1; }
function foo3() { foo2; }
function foo4() { echo foo4-begin; ( defer echo foo4-subshell; foo3; ); echo foo4-end; }
foo4

output

foo4-begin
foo1
foo2
foo4-subshell
foo4-end

Hey, what license is this? If you could declare this code as e.g. MIT-Licensed, I could use it in my OSS project.

Short snippets like this are almost never considered substantial enough to be licenceable. The reason being that someone could reasonably come up with an identical solution fairly quickly.

amaze craft