say_do, die, execute, etc.

functions.sh

#!/bin/bash

main() {
    execute echo hi ;
    execute true ;
    # execute false || echo "$? from execute false" ;
    # { execute false; } || echo "$? from execute false" ;
    ( execute false; ) || echo "$? from execute false" ;
    say_do echo howdy ;
    say_do true ;
    say_do false || echo "$? from execute false" ;
    vexecute true ;
    # vexecute false || echo "$? from vexecute false" ;
    # { vexecute false; } || echo "$? from vexecute false" ;
    ( vexecute false; ) || echo "$? from vexecute false" ;
}

execute() {
  "$@" || die "ERROR: '$?' from {$*}."
}
vexecute() {
  local e=''
  echo "$@" 1>&2 ;
  "$@" || e=$?
  echo 1>&2 ;
  [[ 0 -eq $e ]] || die "ERROR: '$?' from {$*}."
}
say_do() {
  echo "$@" 1>&2 ;
  "$@"
}
vsay_do() {
  local e=''
  say_do "$@" || e=$?
  echo 1>&2 ;
  return $e
}
die() { echo $1 ; exit 1 ; }

main "$@"

#