How to make environment variables permanent?

Permanent Environment Variables in Linux

Environment variables in Linux are a set of dynamic named values that can influence the behavior of running processes on a computer system. These variables are typically used to configure system settings, define file paths, and store other important information that applications and shell scripts can access.

However, the environment variables set during a user's login session or in a shell script are typically only temporary and will be lost when the session or script ends. To make environment variables persistent and available across multiple sessions, you need to set them in a system-wide or user-specific configuration file.

Here are the steps to make environment variables permanent in Linux:

1. Determine the Appropriate Configuration File

The location and name of the configuration file to use depends on whether you want the environment variable to be system-wide or user-specific:

• System-wide: Edit the /etc/environment file, which is read by the system during the boot process and applies to all users.
• User-specific: Edit the ~/.bashrc file (or ~/.bash_profile for login shells) in your home directory, which is read when you log in and applies only to the current user.

The choice between system-wide or user-specific depends on your needs. System-wide environment variables affect all users, while user-specific variables only affect the individual user.

2. Add the Environment Variable

Once you've determined the appropriate configuration file, you can add the environment variable using the following syntax:

VARIABLE_NAME="value"

For example, to set the EDITOR environment variable to the nano text editor, you would add the following line to the configuration file:

EDITOR="/usr/bin/nano"

3. Save the Configuration File and Reload the Environment

After adding the environment variable, save the configuration file and either log out and back in or run the following command to reload the environment:

source /path/to/configuration/file

For example, if you edited the ~/.bashrc file, you would run:

source ~/.bashrc

This will ensure that the new environment variable is available in the current shell session and any new sessions you start.

4. Verify the Environment Variable

To verify that the environment variable has been set correctly, you can use the echo command to print its value:

echo $VARIABLE_NAME

This should output the value you set in the configuration file.

By following these steps, you can make environment variables permanent in your Linux system, ensuring that your applications and scripts have access to the necessary configuration settings across multiple sessions.