#!/bin/bash
#extracting command text_text_text_line options as parameters

help_info(){
  echo "NAME"
  echo "\t$0"
  echo "SYNOPSIS"
  echo "\t$0 is a shell test about process options"
  echo "DESCRIPTION"
  echo "\toption like -a -b param1 -c param2 -d"
}

if [ $# -lt 0 ]
then
  help_info
fi

nomal_opts_act()
{
  echo -e "\n### nomal_opts_act ###\n"

  while [ -n "$1" ]
  do
  case "$1" in 
    -a)
      echo "Found the -a option"
      ;;
    -b)
      echo "Found the -b option"
      echo "The parameter follow -b is $2" 
      shift
      ;;
    -c)
      echo "Found the -c option"
      echo "The parameter follow -c is $2"
      shift
      ;;
    -d)
      echo "Found the -d option"
      ;;
     *)
       echo "$1 is not an option"
      ;;
  esac
  shift
  done
}

#用shell命令自建的選項解析，可以按照自己的想法實現
#優點：自己定制，沒有做不到，只有想不到
#缺點：麻煩

getopt_act()
{
  echo -e "\n### getopt_act ###\n"

  GETOPTOUT=`getopt ab:c:d "$@"`
  set -- $GETOPTOUT 
  while [ -n "$1" ] 
  do
  case $1 in 
    -a)
      echo "Found the -a option"
      ;;
    -b)
      echo "Found the -b option"
      echo "The parameter follow -b is "$2""
      shift
      ;;
    -c)
      echo "Found the -c option"
      echo "The parameter follow -c is "$2""
      shift
      ;;
    -d)
      echo "Found the -d option"
      ;;
    --)
      shift
      break
      ;;
     *)
       echo "Unknow option: "$1""
      ;;
  esac
  shift
  done

  param_index=1
  for param in "$@"
  do
    echo "Parameter $param_index:$param"
    param_index=$[ $param_index + 1 ] 
  done
}

#用getopt命令解析選項和參數
#優點：相對與getopts來說是個半自動解析，自動組織選項和參數，用 -- 符號將選項與參數隔開
#缺點：相對于getopts的缺點
#1.需要與set -- 命令配合，不是必須，需要手動shift
#2.選項參數中不支持空格如 -a -b dog -c "earth moon" -d -f param1 param2 就會解析錯誤

getopts_act()
{
  echo -e "\n### getopts_act ###\n"
  while getopts :ab:c:d ARGS
  do
  case $ARGS in 
    a)
      echo "Found the -a option"
      ;;
    b)
      echo "Found the -b option"
      echo "The parameter follow -b is $OPTARG"
      ;;
    c)
      echo "Found the -c option"
      echo "The parameter follow -c is $OPTARG"
      ;;
    d)
      echo "Found the -d option"
      ;;
     *)
       echo "Unknow option: $ARGS"
      ;;
  esac
  done

  shift $[ $OPTIND -1 ] 
  param_index=1
  for param in "$@"
  do
    echo "Parameter $param_index:$param"
    param_index=$[ $param_index + 1 ] 
  done
}

#getopts 命令解析選項和參數
#優點：可在參數中包含空格如：-c "earth moon"
#      選項字母和參數值之間可以沒有空格如：-bdog
#      可將未定義的選項綁定到?輸出
#      Unknow option: ?

nomal_opts_act -a -b dog -c earth -d -f param1 param2
getopts_act -a -b dog -c "earth moon" -d -f param1 param2
getopt_act -a -b dog -c earth -d -f param1 param2