Environment Variables
You can run printenv
or env
in your terminal
1)How to set Environment variables:-
myVAR=hello
printenv myVAR=hello
OR echo $myVAR
2)How to unset it?
unset myVAR
then echo $myVAR
3)If you type export myVAR=hello
then you can do echo $myVAR
You can add this line in user profile. The tilde symbol (~) represents the home directory.
a)~/.bash_profile (CentOS)
b)~/.bash (Ubuntu)
Add this line in any one of the file
export myVAR=hello
You can echo in new terminal but you won’t be able to echo in your current shell
To solve this, type source ~/.profile
then it will show the output in your current shell.
But if you open in new tab in your current shell, then it won’t show the output.
Then add this line export myVAR=hello
in ~/.bashrc