linux - 有效的赋值运算符 Bash

Question

在我的 bash 脚本中，我尝试使用等号 (=) 运算符作为 IF 语句的输入，可以这样做吗？

echo "Plese enter an operator as shown in the brackets (-)subtract, (*)Multiply, (+)Add, (/)divide, quit(=)?"
read operator
..........

if [[ $operator == '=' ]]; then 
'do something'
fi

Answer 1

我不明白你为什么不能这样做。

> operator==
> echo $operator
=
> if [[ $operator == '=' ]]; then echo 'ok'; fi;
ok

Answer 2

试试这个shell.sh：

#!/bin/sh
EQUAL="=" #this is our operator
echo "Please enter operator"
read operator

if [ $operator = $EQUAL ]; then
    echo "Entered = "
else
    echo "Not = entered"
fi

执行：

:~$ sh shell.sh
Please enter operator
=
Entered = 
:~$ sh shell.sh
Please enter operator
-
Not = entered
:~$ 

学习参考