Introduction to environment variable configuration files

The role of an environment variable

Defines the user's operating environment.

For example: path, ps1

 

Two source command

sourcece configuration file

or

. config file

After modifying the configuration file, you must log out and log in again to take effect. You can use the source command without logging in again.

 

Introduction to three environment variable configuration files

Environment variables such as PATH, HISTSIZE, PS1, and HOSTNAME are written into the corresponding environment variable configuration files.

The environment variable configuration file mainly defines the system default environment variables that take effect on the system operating environment, such as PATH.

 

Four common environment variable configuration files

 

The above environment variables are used when logging in.

The configuration file placed in the home directory only works when the current user is logged in.

The configuration files placed in the etc directory work for all users to log in.