Linux shell系统下执行export及使用man bash

给大家推荐一款很不错的Linux shell系统很有学习价值，这里我主要讲解Linux shell系统的应用，包括介绍Linux shell知识等方面。

一、在Linux shell下，执行export：

declare -x LANG="en_US"这个LANE环境变量，就是我们希望去修改的，但是在哪里修改，比较合适呢？

二、Linux shell使用man bash：

When bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable. The --noprofile option may be used when the shell is started to inhibit this behavior.

即bash在登录时，会依次读取这些配置文件：