options.sh

#!/usr/bin/env bash

set -o errexit -o pipefail -o nounset -o noclobber

if [[ -z "$BASH_VERSION" ]]; then
  echo "This script requires bash."
  exit 1
fi

if [[ "$BASH_VERSION" < "4.0" ]]; then
  echo "This script requires bash version 4.0 or higher."
  if [[ "$(uname -s)" == "Darwin"* ]]; then
    echo "You can install it with Homebrew: brew install bash"
  fi
  exit 1
fi

if [[ -z "$(command -v getopt)" ]]; then
  echo "getopt is not installed. Please install it and try again."
  exit 1
fi

getopt --test > /dev/null && true
if [[ $? -ne 4 ]]; then
  echo "I'm sorry, \"getopt --test\" has failed in this environment."
  echo "Please install the newer version of getopt and try again."
  exit 1
fi

__options_bash_skip_help=1
__options_bash_skip_version=1

__options_bash_program_name=""
__options_bash_program_version=""
__options_bash_program_description=""

declare -A __options_bash_command_names
declare -A __options_bash_command_descriptions
declare -A __options_bash_command_has_arg
declare -A __options_bash_command_aliases
__options_bash_check_commands=1

declare -A __options_bash
__options_bash_args=""
__options_bash_command=""

define_program() {
  # name version description
  __options_bash_program_name="$1"
  __options_bash_program_version="$2"
  __options_bash_program_description="$3"
}

define_command() {
  # names description has_arg
  # has_arg: "" - no argument
  # has_arg: "arg" - required argument, where "arg" is the name of the argument

  local names
  IFS=', ' read -ra names <<< "$1"
  __options_bash_command_names["${names[0]}"]="$1"
  __options_bash_command_descriptions["${names[0]}"]="${2:-}"
  __options_bash_command_has_arg["${names[0]}"]="${3:-}"

  for name in "${names[@]}"; do
    if [[ "$name" == "--"* ]]; then
      if [[ "$name" == "--" ]]; then
        echo "Error: Invalid long option '$name'"
        exit 1
      fi
    elif [[ "$name" == "-"* ]]; then
      if [[ ! "$name" =~ ^-[a-zA-Z0-9]$ ]]; then
        echo "Error: Invalid short option '$name'"
        exit 1
      fi
    else
      __options_bash_check_commands=0
    fi
    __options_bash_command_aliases["$name"]="${names[0]}"
  done
}

parse_options() {
  local long_options=""
  local short_options=""

  for option in "${!__options_bash_command_aliases[@]}"; do
    local command="${__options_bash_command_aliases[$option]}"
    if [[ "$option" == "--"* ]]; then
      if [[ -n "$long_options" ]]; then long_options+=","; fi
      long_options+="${option#--}"
      if [[ -n "${__options_bash_command_has_arg[$command]}" ]]; then long_options+=":"; fi
    elif [[ "$option" == "-"* ]]; then
      short_options+="${option#-}"
      if [[ -n "${__options_bash_command_has_arg[$command]}" ]]; then short_options+=":"; fi
    fi
  done

  local parsed
  local status=0
  parsed=$(getopt -o "$short_options" -l "$long_options" -n "${__options_bash_program_name}" -- "$@") || status=$?

  if [[ $status -ne 0 ]]; then
    echo "Try '${__options_bash_program_name} --help' for more information."
    exit 1
  fi

  eval set -- "$parsed"
  while true; do
    if [[ "$1" == "--" ]]; then
      shift
      break
    fi
    local option="${__options_bash_command_aliases["$1"]}"
    if [[ -z "$option" ]]; then
      echo "Error: Unknown option '$1'"
      echo "Try '${__options_bash_program_name} --help' for more information."
      exit 1
    fi
    shift
    if [[ -n "${__options_bash_command_has_arg[$option]}" ]]; then
      __options_bash["$option"]="$1"
      shift
    else
      __options_bash["$option"]=""
    fi
  done

  if [[ ${__options_bash_check_commands} -eq 0 ]]; then
    if [ "$#" -eq 0 ]; then
      echo "Error: No command specified"
      echo "Try '${__options_bash_program_name} --help' for more information."
      exit 1
    fi
    local unknown_command=0
    for command in "${!__options_bash_command_aliases[@]}"; do
      if [[ "$command" == "-"* ]]; then continue; fi
      if [[ "$command" == "$1" ]]; then
        unknown_command=1
        break
      fi
    done
    if [[ $unknown_command -eq 0 ]]; then
      echo "Error: Unknown command '$1'"
      echo "Try '${__options_bash_program_name} --help' for more information."
      exit 1
    else
      __options_bash_command="${__options_bash_command_aliases[$1]}"
    fi
  fi

  __options_bash_args="$@"
}

show_help() {
  echo "${__options_bash_program_name} ${__options_bash_program_version}"
  echo "${__options_bash_program_description}"
  echo ""
  echo "Usage: ${__options_bash_program_name} [options] [command] [command options]"
  echo ""
  echo "Options:"
  for option in "${!__options_bash_command_names[@]}"; do
    if [[ "$option" == "--"* ]]; then continue; fi
    if [[ "$option" != "-"* ]]; then continue; fi
    echo "  ${__options_bash_command_names[$option]}"
  done
  for option in "${!__options_bash_command_names[@]}"; do
    if [[ "$option" != "--"* ]]; then continue; fi
    echo "  ${__options_bash_command_names[$option]}"
  done
  echo ""
  echo "Commands:"
  for command in "${!__options_bash_command_names[@]}"; do
    if [[ "$command" == "-"* ]]; then continue; fi
    echo "  ${__options_bash_command_names[$command]}"
  done
}

show_version() {
  echo "${__options_bash_program_name} ${__options_bash_program_version}"
}