An environment variable is a dynamic-named value containing information about your login session, set configuration options, and customize the shell environment in Linux-based operating systems. In simple terms, an environment variable is used to define a location for storing a value, you can also refer to its symbolic name. These values are stored within the system and are used by command-line applications. The stored value can be deleted, displayed, edited, and re-saved.
2.1 Use printenv to print all
environment variables.
2.2 You can set a temporary environment variable by:
Then call this variable as $MY_NAME, for example:
Notice that the above environment variables are available only for the current session. If you open a new shell, or if you log out, all variables will be lost.
Please verify this.
2.3 Setting a Persistent Environment Variable
One way to set a persistent environment variable is to use the
user-based configuration file .bash_profile in your home
directory. With Bash, you can declare the variables in the following
format:
Please add the above line to your .bash_profile, then
save .bash_profile.
To update current environment variables, run:
Now, we have made $MY_NAME a persistent environment
variable, and it will be loaded every time you log in.