长求总：全局变量在/etc目录下，用户自定义在~/目录下，仅针对bash shell就找%bashrc%类文件

 

1. /etc/profile

对所有用户、所有shell均有效

登陆操作系统后，该文件被读取，从/etc/profile.d的配置文件中搜集shell相关设置

生效方式：source命令或重启操作系统

# /etc/profile: system-wide .profile file for the Bourne shell (sh(1))
# and Bourne compatible shells (bash(1), ksh(1), ash(1), ...).

2. /etc/.bashrc 或 /etc/bash.bashrc

对所有运行bash shell的用户生效

打开bash shell时，该文件被读取

生效方式：重启bash shell

# System-wide .bashrc file for interactive bash(1) shells.

# To enable the settings / commands in this file for login shells as well,
# this file has to be sourced in /etc/profile.

3.~/.bash_profile >> ~/.bash_login >> ~/.profile

对当前用户生效

用户登陆操作系统后，根据优先级次序读取该用户的文件

生效方式：source命令或重启操作系统

# ~/.profile: executed by the command interpreter for login shells.
# This file is not read by bash(1), if ~/.bash_profile or ~/.bash_login exists.

4.~/.bashrc

对当前运行bash shell的用户生效

打开bash shell时，该用户的文件被读取（一般在~/.bash_profile之后）

生效方式：重启bash shell

# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc) for examples

5.~/.bash_logout

对当前关闭bash shell的用户生效

关闭bash shell时，该用户的文件被读取

生效方式：重启bash shell

# ~/.bash_logout: executed by bash(1) when login shell exits.