Check required commands exist

Exit with an error if any name in COMMANDS is missing from PATH.

18^th August 2026

check_prereqs() {
  local error_count=0

  for i in "${COMMANDS[@]}"; do
    command=$(command -v "${i}")
    if [[ -z $command ]]; then
      printf '%s is not in your command path\n' "${i}"
      error_count=$((error_count + 1))
    fi
  done

  if [[ $error_count -gt 0 ]]; then
    printf '%d errors located - fix before re-running\n' "${error_count}"
    exit 1
  fi
}

Caveats

Set COMMANDS to the list of command names to require before calling check_prereqs.