在 shell 脚本中设置环境变量不会使其对 shell 可见 [英] Setting environment variable in shell script does not make it visible to the shell

问题描述

我想使用一个可以调用的 shell 脚本来设置一些环境变量.但是，执行脚本后，我在 bash 中没有看到使用printenv"的环境变量.

I want to use a shell script that I can call to set some environment variables. However, after the execution of the script, I don't see the environment variable using "printenv" in bash.

这是我的脚本:

#!/bin/bash

echo "Hello!"
export MYVAR=boubou
echo "After setting MYVAR!"

当我执行./test.sh"时，我看到了:

When I do "./test.sh", I see:

Hello!
After setting MYVAR!

当我执行printenv MYVAR"时，我什么也看不到.

When I do "printenv MYVAR", I see nothing.

你能告诉我我做错了什么吗?

Can you tell me what I'm doing wrong?

推荐答案

这就是环境变量的工作方式.每个进程都有一个环境副本.进程对其副本所做的任何更改都会传播到进程的子进程.但是，它们不会传播到进程的父进程.

This is how environment variables work. Every process has a copy of the environment. Any changes that the process makes to its copy propagate to the process's children. They do not, however, propagate to the process's parent.

解决此问题的一种方法是使用 source 命令:

One way to get around this is by using the source command:

source ./test.sh

或

. ./test.sh

(这两种形式是同义词).

(the two forms are synonymous).

执行此操作时，bash 将执行脚本中的每个命令，就像在提示符下键入一样，而不是在子 shell 中运行脚本.

When you do this, instead of running the script in a sub-shell, bash will execute each command in the script as if it were typed at the prompt.

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