從動態串列創建互動式Shell提示選單？

以下提示應允許用戶根據輸出到陣列的填充串列進行選擇，然后列印串列及其索引，并要求用戶從串列中選擇一個數字，然后將其設定為變數。

Multiple devices detected, please select one from the list:
1. Device1
2. Device2
3. Device3

1
You have selected device Device1

下面的代碼不起作用并且有很多語法錯誤，首先我希望腳本檢測輸出是否arr=($(ip ad|awk '/state UP/ {print $2}'))包含多個條目，如果是，則運行腳本，否則設定默認值。case 陳述句不是動態的，但是，如果像下面這樣的超過 2 個案例會失敗，也許是一個回圈？

host_interfaces()
{
   arr=($(ip ad|awk '/state UP/ {print $2}'))
   echo "Multiple devices detected, please select one from the list:"
   for i in "${!arr[@]}"; do
   printf "%s%s\n" "$i.  " "${arr[$i]}"
   done
   PS3='Please enter your choice: '
   select opt in "${arr[@]}"
   do
      case $opt in
            "1")
               echo "You have selected device $opt"
               export HOST_INTERFACE=$opt
               ;;
            "2")
               echo "You have selected device $opt"
               export HOST_INTERFACE=$opt
               ;;
            "Quit")
               break
               ;;
            *) echo "invalid option ;;
      esac
   done
}

uj5u.com熱心網友回復：

一個辦法：

#! /bin/bash

declare HOST_INTERFACE=

function host_interfaces() {
    local -a arr=($(ip ad | awk '/state UP/ {gsub(/:/, "", $2); print $2}'))
    if [ "${#arr[@]}" -eq 1 ]; then
        HOST_INTERFACE="${arr[0]}"
        return 0
    fi
    local opt=
    HOST_INTERFACE=
    echo "Multiple devices detected, please select one from the list:"
    PS3='Please enter your choice: '
    # Add "Quit" value to the items
    select opt in "${arr[@]}" Quit; do
        # "opt" does not contains the number but the associated value
        case $opt in
            "Quit")
                # 
                break
            ;;
            "")
                # No value found
                echo "invalid option"
            ;;
            *)
                echo "You have selected device $opt"
                export HOST_INTERFACE=$opt
                break
            ;;
        esac
    done
}

host_interfaces

uj5u.com熱心網友回復：

這，也許？

host_interfaces()
{
  local opt='' h=''
  arr=($(ip ad|awk '/state UP/ {print $2}'))
  if [ "${#arr[@]}" -eq 1 ]; then
    echo "One single device detected"
    h="${arr[0]}"
  elif [ "${#arr[@]}" -gt 1 ]; then
    echo "Multiple devices detected, please select one from the list:"
    PS3='Please enter your choice: '
    select opt in "${arr[@]}" Quit
    do
      case "$opt" in
        "Quit")
          break
          ;;
        "")
          echo "Invalid choice"
          h=''
          ;;
        *)
          echo "You have selected device $opt"
          h="$opt"
          ;;
      esac
    done
  else
    echo "No device detected"
  fi
  echo "Selected device: ${h:-none}"
  export HOST_INTERFACE="$h"
  [ -z "$h" ] && return 1 || return 0
}

請注意，如果未找到或選擇有效設備，則該函式回傳 1，否則回傳 0。因此您可以將其用于：

if host_interfaces; then
  echo "HOST_INTERFACE = $HOST_INTERFACE"
else
  echo "No device selected"
fi

uj5u.com熱心網友回復：

在這里可以簡單地使用

dialog --backtitle "Device selection" --title "Multiple devices detected" --menu "please select one from the list:" 10 45 4 1 "Device1" 2 "Device2" 3 "Device3"

看 man dialog

標籤：linux 猛击 循环 贝壳 脚本编写

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