Question

我写了这个脚本来比较bash中的2个数字但它给了我一些数字的错误答案。就像我给它2＆amp; 2输入一样，它给了我＆＃34; X大于Y＆＃34;

#!/bin/bash 
read num1
read num2
if [ $num1 > $num2 ]
    then 
        echo "X is greater than Y"
elif [ $num1 < $num2 ]
    then 
        echo "X is less than Y"
elif [ $num1 = $num2 ]
    then 
        echo "X is equal to Y"
fi

Answer 1

您可以尝试使用bash算术上下文：

#!/bin/bash 
read num1
read num2
if (( num1 > num2 ))
    then 
        echo "X is greater than Y"
elif (( num1 < num2 ))
    then 
        echo "X is less than Y"
elif (( num1 == num2 ))
    then 
        echo "X is equal to Y"
fi

Answer 2

这对我有用：

cmp() {
    num1="$1"
    num2="$2"

    if [ $num1 -gt $num2 ]
        then 
            echo "X is greater than Y"
    elif [ $num1 -lt $num2 ]
        then 
            echo "X is less than Y"
    elif [ $num1 -eq $num2 ]
        then 
            echo "X is equal to Y"
    fi
}

然后看结果：

cmp 2 3
X is less than Y

cmp 2 2
X is equal to Y

cmp 2 1
X is greater than Y

由于您使用的是bash，我建议您使用[[ ... ]]代替[ ... ]括号。

Answer 3

#!/bin/sh

echo hi enter first  number
read num1 

echo hi again enter second number
read num2

if [ "$num1" -gt "$num2" ]
then
  echo $num1 is greater than $num2
elif [ "$num2" -gt "$num1" ]
then
  echo $num2 is greater than $num1
else
  echo $num1 is equal to $num2
fi

（请注意：我们将使用-gt运算符代表＆gt;， - lt代表＆lt;，== for =）

Answer 4

尽可能少地更改括号 - 进入'double bracket'模式（仅在Bash shell中的bash / zsh中有效）。

如果您希望与sh兼容，则可以保持'single bracket'模式，但需要更换所有操作员。

在'single bracket'模式下，'<','>', '='等运算符仅用于比较字符串。要比较'single bracket'模式中的数字，您需要使用'-gt'，'-lt'，'-eq'

#!/bin/bash 
read num1
read num2
if [[ $num1 > $num2 ]]
    then 
        echo "X is greater than Y"
elif [[ $num1 < $num2 ]]
    then 
        echo "X is less than Y"
elif [[ $num1 = $num2 ]]
    then 
        echo "X is equal to Y"
fi

比较bash脚本中的数字

4 个答案: