[：将 * 作为输入时参数过多

Question

所以我必须用一些简单的函数在 bash 中制作这个小计算器，您可以在下面的代码中看到这些函数（这是调试版本）。但是，在执行过程中，我遇到了一个问题，将 * 输入到 operation2 中会给我 [: too many arguments，但这不会发生在 operation1 中。

我需要计算器将此输入用于 1+1*2 等输入，因为脚本需要继续运行，直到用户输入“=”，因此 while ！环形。我是批处理脚本的新手，所以我不知道我必须改变什么。我从调试中知道它正在调用该脚本所在的字典中的文件列表，所以我相信它一定是误解了命令。

代码如下，在任一操作中读取 * 时发生的问题2。但是，它适用于所有其他输入（+、-、/、=）

#bin/bash +x

begin=$(date +"%s")

echo "Please Enter Your Unix Username:"
read text

userdata=$(grep $text /etc/passwd | cut -d ":" -f1,5,6 | tr -d ',')
echo "The User: $userdata" >> calcusers.txt
date=$(date)
echo "Last Ran calculator.sh on: $date " >> calcusers.txt
echo "---------------------------------------------------------" >> calcusers.txt

name=$(grep $text /etc/passwd | cut -d ":" -f5 | cut -d\  -f1)
echo -n "Hello" $name &&  echo  ", Welcome to calculator.sh."
echo "To begin using calculator.sh to do some calculations simply type a number"
echo "below, followed by the type of sum you want to perform and the input for"
echo "a second number, third and so on. To output the equation simply type =."
set -x
echo "Please Enter a Number:"
read number1
echo "Would you like to Add(+), Subtract(-), Multiply(*) or Divide(/) that number?"
read operation1
echo "Please Enter a Number:"
read number2
total=$(echo "$number1$operation1$number2" | bc)
echo "Would you like to Add(+), Subtract(-), Multiply(*), Divide(/) or Equals(=) that equation?"
read operation2

while [ ! $operation2 = "=" ]
do
     echo "Please Enter a Number:"
     read number3
     total=$(echo "$total$operation2$number3" | bc)
     echo "Would you like to Add(+), Subtract(-), Multiply(*), Divide(/) or Equals(=) that equation?"
     read operation2
done
set +x
echo -n "The total of the equation is" $total && echo "."
termin=$(date +"%s")
difftimelps=$(($termin-$begin))
echo "Thanks for using calculator.sh!"
echo "$(($difftimelps / 60)) minutes and $(($difftimelps % 60)) seconds has passed since the Script was Executed."

exit 0

Answer 1

到处引用你的变量：

while [ ! "$operation2" = "=" ]
# ........^............^

此外，您应该期待用户的无效输入

while [ ! "$operation2" = "=" ]
do
    case "$operation2" in
        [*/+-])
            echo "Please Enter a Number:"
            read number3
            total=$(echo "$total$operation2$number3" | bc)
            ;;
        *)  echo "Invalid operation: '$operation2'"
            ;;
    esac
    echo "Would you like to Add(+), Subtract(-), Multiply(*), Divide(/) or Equals(=) that equation?"
    read operation2
done