Ph.D. in Computer Science at Rutgers University

Environment and Variables

This article will discuss on Bash Environments, built-in variables and how to use bash variables.

The .profile, .bash_logout and .bashrc file

These three files in your home directory have a special meaning to bash. They provide a way for you to setup your account environment atomatically when you log in, log out and invoke another bash shell. If these three files don't exist, then you account is using only the default system file /etc/profile.

.bash_profile is executed for login shells, while .bashrc is executed for interactive non-login shells. When you login (type username and password) via console, either sitting at the machine, or remotely via ssh: .bash_profile is executed to configure your shell before the initial command prompt. But, if you’ve already logged into your machine and open a new terminal window (xterm) then .bashrc is executed before the window command prompt. .bashrc is also run when you start a new bash instance by typing /bin/bash in a terminal.