Bash：意外标记"then"附近的语法错误

Question

错误在第 21 行...

if [ $weight1 -gt $weight2 ];
    then echo "Weight 2 should be greater than Weight 1."
else
    if [ $weight1 -ge 20 ] && [ $weight1 -le 39 ];
        then echo "Weight 1 is bike."
    else 
        echo "Weight 1 is either bicycle, car, van or lorry."
    fi
fi

Answer 1

我完成了\没有看到问题，在我的测试中then关键字适用于您的情况，无论如何，您的代码上注明了一些：

1. 把then放在if操作员的线上：

   if [ $weight1 -ge 20 ] && [ $weight1 -le 39 ]; then
   

2. 将变量括在引号中：

   if [ "$weight1" -ge 20 ] && [ "$weight1" -le 39 ]; then
   

3. 我建议使用-a键，而不是对[应用程序进行两次调用：

   if [ "$weight1" -ge 20 -a "$weight1" -le 39 ]; then
   

注意：错误Syntax error near unexpected token 'then'主要在少数情况下会出现：

1. 当您指定then超出大小写if关键字时：

   weight1=21
       then echo "Weight 1 is bike."
   else
       echo "Weight 1 is either bicycle, car, van or lorry."
   fi
   

2. 指定then两次时：

   if [ "$weight1" -ge 20 -a "$weight1" -le 39 ]; then
   then echo "Weight 1 is bike."
   

3. 当您将then放在不正确的位置时，例如，在else运算符之后：

   else
   then
       echo "Weight 1 is either bicycle, car, van or lorry."
   fi
   

Answer 2

只是

chmod +x test.sh

第一行： 添加#!/bin/bash

然后做：

./test.sh

它正在解决问题