Environment variables are variables that can be used across commands and programs and hold information about the environment.

What happens when you store this in ~/.bash_profile?

export USER="Hemanta"

• The line USER="Hemanta" sets the environment variable USER to a name "Hemanta". Usually the USER variable is set to the name of the computer’s owner.

• The line export makes the variable to be available to all child sessions initiated from the session you are in. This is a way to make the variable persist across programs.

• At the command line, the command echo $USER returns the value of the variable. Note that $ is always used when returning a variable’s value. Here, the command echo $USER returns the name set for the variable.

We can return a list of the environment variables for the current user by typing the env command.

env