linux - 如何在 Linux 中更新环境变量？

Question

我定义了一个环境变量:export NBR_PROCESS=2

基本上，我应该能够更新变量，但是当我执行以下脚本时，每次运行都会得到相同的结果:

#!/bin/bash
echo "Script 2: Before decrement : $NBR_PROCESS"
export NBR_PROCESS=$(($NBR_PROCESS - 1))
echo "Script 2: After decrement : $NBR_PROCESS"

每次执行我都会得到以下相同的结果:

Script 2: Before decrement : 2
Script 2: After decrement : 1

我想做的是通过运行脚本来减少变量 NBR_PROCESS。

Answer 1

你必须“来源”

来源 your_script

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编辑1
参见 this answer...

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编辑 2

。文件名[参数]或者源文件名[参数]

Complete explanations:

Read and execute commands from the filename argument in the current shell context. If filename does not contain a slash, the PATH variable is used to find filename. When Bash is not in POSIX mode, the current directory is searched if filename is not found in $PATH. If any arguments are supplied, they become the positional parameters when filename is executed. Otherwise the positional parameters are unchanged. The return status is the exit status of the last command executed, or zero if no commands are executed. If filename is not found, or cannot be read, the return status is non-zero. This builtin is equivalent to source.