编写一个menu的shell脚本程序，执行后的界面为: Number Name For Linux Menu 1 exit leave menu or return 2 menu goto another local menu 3 vi deit a file 4 mail read a mai l 5 send send mail to someone 6 cal see your calendar . 7 who see who is on the system 8 ls list the fi les in this directory 9 cat display a file on the screen Please enter a number or a name for the action you wish: 要求有清屏功能，能正确地执行各项命令并显示。

好的，以下是一个简单的实现：

#!/bin/bash

# 定义菜单选项数组
options=("exit" "menu" "vi" "mail" "send" "cal" "who" "ls" "cat")

# 定义菜单选项名称数组
names=("leave menu" "goto another local menu" "deit a file" "read a mail" "send mail to someone" "see your calendar" "see who is on the system" "list the files in this directory" "display a file on the screen")

# 定义清屏函数
clear_screen() {
  if [[ "$OSTYPE" == "darwin"* ]]; then
    clear
  else
    reset
  fi
}

# 显示菜单
show_menu() {
  clear_screen
  echo "Number   Name"
  echo "For Linux Menu"
  for i in ${!options[@]}; do
    echo "$i        ${names[$i]}"
  done
  echo ""
}

# 执行命令
execute_command() {
  if [[ "$1" =~ ^[0-9]+$ ]]; then
    # 根据数字执行对应的命令
    if [[ "$1" -ge 0 && "$1" -lt ${#options[@]} ]]; then
      if [[ "$1" -eq 0 ]]; then
        # 退出脚本
        exit 0
      elif [[ "$1" -eq 1 ]]; then
        # 进入另一个菜单，这里简单地调用show_menu函数
        show_menu
      else
        # 执行命令
        command=${options[$1]}
        echo ""
        read -p "Please enter the $command: " args
        eval "$command $args"
      fi
    else
      # 数字不在菜单选项范围内
      echo "Invalid option: $1"
    fi
  else
    # 根据名称执行对应的命令
    index=-1
    for i in ${!names[@]}; do
      if [[ "${names[$i]}" == "$1" ]]; then
        index=$i
        break
      fi
    done
    if [[ "$index" -ne -1 ]]; then
      execute_command $index
    else
      # 名称不在菜单选项范围内
      echo "Invalid option: $1"
    fi
  fi
}

# 主程序
show_menu
while true; do
  read -p "Please enter a number or a name for the action you wish: " option
  execute_command $option
  read -p "Press ENTER to return to menu..." enter_key
  show_menu
done

这个脚本定义了两个数组，一个是菜单选项数组，包含了9个命令，另一个是菜单选项名称数组，包含了对应的名称。在show_menu函数中，遍历这两个数组输出菜单。在execute_command函数中，根据输入的数字或名称执行对应的命令。最后，在主程序中循环读取输入，执行命令，并显示菜单。