ways to loop through script and function arguments

bash-arguments-parsing.sh

# looping over all argumetns while shifting the arguments array
function looping-over-all-arguments-destructive() {
  while [[ $# -gt 0 ]];
    do
      opt="$1";
      shift;             #expose next argument
      case "$opt" in
            "--file" )
               INCLUDE=$1;
               shift;;
            "--flag" )
               FLAG=1;
               ;;
            *) echo >&2 "Invalid option: $opt"; exit 1;;
       esac
    done
}

# looping over arguments while removing only the proccessed ones
# looping-over-all-arguments 1 2 3 qwe asd
function looping-over-selected-arguments() {
  local rest=()
  for opt in "${@}"
  do
      case "$opt" in
          [0-9] ) echo "proccessed $opt" ;; # 1 2 3
          *) rest+=("$opt") ;;
     esac
  done
  some_other_function ${rest[@]} # qwe asd
}

# look at first argument, aka subcommand
function main() {
    local cmd="$1";
    shift;
    case "$cmd" in
        "command" ) call_subcommand $@;;
        *) echo >&2 "Unknown command: $cmd"; exit 1;;
    esac
}

main $@