xopts

#
# ANALYSIS:
#  - not possible to set global variables when calling get_opts
#    using command substitution, to return result
#  - not possible to set positional parameters in a function
#    where \${@} refers to is own parameter array
#
# RESULT:
#  - use get_opts when only setting global variables
#  - use raw when arguments on tail are expected
# ------------------------------------------------
#
# Use when expecting tail arguments, as well as options
#
declare -a in_args=("${@}")
declare -a out_args=()
declare -i i=0

while (( i < ${#in_args[@]} )); do
  declare arg="${in_args[$i]}"
  case ${arg} in
    -h|--help) show_help "${SYNTAX}" ;;
    -m|--message)
      (( i = i + 1 ))
      MESSAGE="${in_args[$i]}"
      echo "in_args[$i]: ${in_args[$i]}" >&2
      echo "MESSAGE: ${MESSAGE}" >&2
      ;;
    *)
      (( ${#out_args[@]} > 0 )) \
          && out_args=("${out_args[@]}" "${arg}") \
          || out_args=("${arg}")
      ;;
  esac
  (( i++ ))
done

(( ${#out_args[@]} > 0 )) \
  && set -- "${out_args[@]}"

# ------------------------------------------------
#
# Use when only setting global variables
#
get_opts() {
  local -a in_args=("${@}") out_args=()
  local -i i=0

  while (( i < ${#in_args[@]} )); do
    local arg="${in_args[i]}"
    case ${arg} in
      -h|--help) get_help ;;
      -l|--like)
        (( $i++ ))
        LIKE="${in_args[i]}"
        ;;
      -s|--show)
        (( $i++ ))
        SHOW="${in_args[i]}"
        ;;
      *) out_args+=("${arg}") ;;
   esac
   (( i++ ))
  done

  FILES=("${out_args[@]}")
}

# ------------------------------------------------
#  Dead Simple Positional Parameter Parse
# ------------------------------------------------
#
__get_opts() {
  while (( $# > 0 )); do
    local arg="${1}"; shift;
    case ${arg} in
      --help)      { usage; exit 0; }   ;;
      --list)      LIST=${TRUE}         ;;
      --less*)
        LESS=${TRUE}
        [[ ${arg} =~ '=' ]] \
          || error "No script file was provided as argument" 2 \
          && ITEM="${arg#*=}"
        ;;
      --show*)
        SHOW=${TRUE}
        [[ ${arg} =~ '=' ]] \
          || error "No script file was provided as argument" 3 \
          && ITEM="${arg#*=}"
        ;;
      --term*)
        GOT_TERM=${TRUE}
        [[ ${arg} =~ '=' ]] \
          || error "No term was provided as argument" 4 \
          && TERM="${arg#*=}"
        ;;
      *)  error "Unknown option: ${arg}" 1 ;;
   esac
  done
  return 0
}

get_opts() {
  while (( $# > 0 )); do
    local arg="${1}"; shift;
    case ${arg} in
      --help)       { usage; exit 0; }   ;;
      --log-value)  LOG_VALUE=${TRUE}    ;;
      --log)        LOG_DATA=${TRUE}     ;;
      --display)    DISPLAY_DATA=${TRUE} ;;
      --inform)     INFORM=${TRUE}       ;;
      --quotes*)
        SPEAK_DATA=${TRUE}
        [[ ${arg} =~ '=' ]] && VOICE="${arg#*=}"
        ;;
      --price) # one and done, get the rest
        __get_price "${@}"
        exit 0 ;;
      --btc) # one and done, get the rest
        __btc_value "${@}"
        exit 0 ;;
      --export)     EXPORT_DATA=${TRUE}  ;;
      *)            die "Unknown option: ${arg}" ;;
   esac
  done
  return 0
}