There are quite a few examples around, just google the parameters 'set euo pipefail' (first hit [0])

you're right that just putting the set options on top of your file would be a bad idea. you need to write your script to actually account for these errors, making possible exitcodes entirely transparent

    1 #!/bin/bash
    2
    3 set -euo pipefail
    4 if ${DEBUG:-false}; then set -x; fi
    5
    6 function random_exitcode(){
    7         return $(( RANDOM % 5))
    8 }
    9
   10 function handle_error(){
   11   case "$?" in
   12     1)  echo "handling exitcode 1!";;
   13     2)  echo "handling exitcode 2!!";;
   14     3)  echo "handling exitcode 3!!!";;
   15     *)  echo "encountered unexpected exitcode: $?"; exit 2;;
   16   esac
   17 }
   18
   19 random_exitcode || handle_error

or, if you don't like functions:

  random_exitcode || LAST_EXITCODE=$?
  case "${LAST_EXITCODE:=0}" in ...

[0] https://coderwall.com/p/fkfaqq/safer-bash-scripts-with-set-e...

Many thanks, I very much appreciate the effort you put into your reply, and your followup.