Linux Variables: Shell Variables: Local Variables : Environment Variables

 https://www.tutorialspoint.com/unix/unix-using-variables.htm

https://www.serverlab.ca/tutorials/linux/administration-linux/how-to-set-environment-variables-in-linux/

export NAME=VALUE

export JAVA_HOME=/opt/openjdk11

unset VARIABLE_NAME

unset JAVA_HOME

::Listing All Set Environment Variables::

set

variable_name=variable_value

NAME="John Doe"

echo $NAME

readonly NAME

export NAME

Linux Variable Types

When a shell is running, three main types of variables are present −

Local Variables

Environment Variables 

Shell Variables