Comparison of 3 methods of shell script passing parameters _linux Shell

#!/bin/bash #extracting command text_text_text_line options as Parameters Help_info () {echo "NAME" echo "\t$0" Ech O "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 "$" Do case "In-a" echo "Found the-a option";;
    -B) echo "Found the-b option" echo "The parameter follow-b is $" shift;
    -c) echo "Found the-c option" echo "The parameter follow-c is $" shift;
     -D) echo "Found the-d option";;
  *) echo "is not a option";; ESAC shift Done} #用shell命令自建的选项解析, can follow their own ideas to achieve #优点: their own customization, not to do, only unexpected #缺点: Trouble Getopt_act () {ECHO-E "\n### Getopt_ac
     T ###\n "getoptout= ' getopt ab:c:d" $@ "' Set--$GETOPTOUT while [-N ' $] do case $ in-a) echo "Found the-a option";;
    -B) echo "Found the-b option" echo "The parameter follow-b is" $ "" Shift ";
    -c) echo "Found the-c option" echo "The parameter follow-c is" $ "" Shift ";
    -D) echo "Found the-d option";;
     --) shift break;;
  *) echo "unknow option:" "$"; ESAC shift did param_index=1 for Param in ' $@ do echo ' Parameter $param _index: $param ' param_index=$[ $param _index + 1] done} #用getopt命令解析选项和参数 #优点: Compared with getopts is a semi-automatic parsing, automatic organization options and parameters, with--symbols to separate options and parameters #缺点: relative to the shortcomings of the getopts #1. Need to Set--command fit, not required, requires manual shift #2. Spaces such as-a-b dog-c "Earth Moon"-d-f param1 param2 () {getopts_act) are parsed in option arguments echo-e
      "\n### getopts_act ###\n" while Getopts:ab:c:d ARGS does 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 to param in ' $@ ' do echo ' Parameter $param _index: $param ' param_index=$[$param _index + 1] done} #getopts command resolution options and Parameters #优点: You can include spaces in parameters such as:-C "Earth Moon" # option letters and parameter values can have no spaces such as:

-bdog # can bind undefined options to? output # 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