Unix Shell腳本函數

Question

我正在學習在Shell中製作小程序，並且正在研究如何定義使用系統計算器（bc -l）的函數。我會告訴我想要做的事：

#!/bin/bash 
square(){ 
I need help here! 
} 
cube(){ 
I need help here! 
} 
rectangle(){ 
I need help here! 
} 
exit(){ 
help 
} 
I need help here! 
echo "Little program that computes the following:" 
echo "a) Surface of a square" 
echo "b) Volume of a cube" 
echo "c) Surface of a rectangle" 
echo "e) exit" 
echo "Choose the option you want to compute" 
read answer 
if [ $respuesta == "a" ] 
then echo "What's the side of the square" 
read l` 

該行我現在該怎麼calll我的功能「吃」用戶的答案，然後顯示計算後不要。事情變得最糟糕，因爲在計算之後，我必須詢問用戶他是否想繼續或退出。如果有人能幫助我，我將非常感激。對不起我的英語。我不是母語的人。

Answer 1

這是你在找什麼？：

menu="some items to choose from: 
       A) something 
       B) something else" 
sample() { 
    a="$1" 
    b="$2" 
    c="$3" 
    printf "c: %s" "$c" 
    echo "$a+$b" | bc 
    echo "$a*$b" | bc 
    echo "$a/$b" | bc 
} 

add=$(echo "2+2" | bc) 
printf "Added: %s\n" "$add" 

echo "$menu" 
read -p "choose: " choice 

case "$choice" in 
    A) sample "30" "5";; 
    B) sample "2" "2" "2";; 
    *) echo "not a choice";; 
esac 

Answer 2

這裏是一個支持的BASH與SELECT語句中的代碼。對於正方形，立方體，矩形的功能，您應該很好地完成它。

#!/usr/bin/env bash 

square(){ 
echo "I need help here! - square" 
} 
cube(){ 
echo "I need help here! - cube" 
} 
rectangle(){ 
echo "I need help here! - rectangle" 
} 
exit(){ 
echo "help" 
} 

options=("Surface of a square" "Volume of a cube" "Surface of a rectangle" "exit") 

select opt in "${options[@]}" 
do 
    case $opt in 
     "${options[0]}") 
      echo "you chose choice 1" 
      square 
      ;; 
     "${options[1]}") 
      echo "you chose choice 2" 
      cube 
      ;; 
     "${options[2]}") 
      echo "you chose choice 3" 
      rectangle 
      ;; 
     "${options[3]}") 
      break 
      ;; 
     *) echo invalid option;; 
    esac 
done