What are the Environmental Variables?
An environment variable is a dynamic “object” on a computer that stores a value, which in turn can be referenced by one or more software programs.Environment variables are dynamic because they can change. The values they store can be changed to match the current computer system’s setup and design (environment). They can also differ between computer systems because each computer can have a different setup and design (environment).
There are number of environmental variables to set. As an example imagine if you want to config java runtime on your machine you have to set JAVA_HOME variable.
How to set , unset Environmental variables in Linux?
In linux basically we use terminal commands to set and unset environmental variables. To set an environmental variable we use export
If you want to remove once set environmental variable , you can use unset command.
How to view set environmental variables?
If you want to see what are the set environmental variables you can use printenv command. It will print all the current environmental variables in your system.
To show a list including the variables created by yourself you can enter the following command
( set -o posix ; set ) | less