问题

我编写了一个bash脚本来设置环境变量`VAR`，如果它当前尚未设置：

example.sh
```bash
#!/bin/bash

if [ -z $VAR ]; then
    export VAR=abc
fi

现在我在命令行中输入：./example.sh && echo $VAR。我期望得到abc，但结果是空白的。为什么？

<details>
<summary>英文:</summary>

I wrote a bash script to set the environment variable `VAR` if it is currently not set:

example.sh
```bash
#!/bin/bash

if [ -z $VAR ]; then
    export VAR=abc
fi

Now I type this in the command line: ./example.sh && echo $VAR. I expect abc, but the result is blank. Why?

答案1

得分: 1

Use source example.sh or . example.sh