How to Set Environment Variables

Environment variables are dynamic values that affect the processes and behavior of running applications on an operating system. They can store configuration settings, paths to executables, and other critical data. This tutorial will guide you through setting environment variables in Linux, macOS, and Windows.

1. Setting Environment Variables in Linux

1.1. Temporary Variables

To set an environment variable for the duration of a terminal session, use the following command:

export VAR_NAME="value"

For example:

export MY_VAR="Hello World"

This variable will be available in the current terminal session and can be accessed using:

echo $MY_VAR

1.2. Permanent Variables

To make the variable persist across sessions, you can add it to your shell’s configuration file. For bash users, edit ~/.bashrc:

nano ~/.bashrc

Add the following line:

export MY_VAR="Hello World"

Save and apply the changes:

source ~/.bashrc

2. Setting Environment Variables in macOS

The process for macOS is similar to Linux. Use Terminal to set temporary and permanent variables in the same way.

2.1. Temporary Variables

export MY_VAR="Hello from macOS"

2.2. Permanent Variables

Edit ~/.bash_profile:

nano ~/.bash_profile

Add the export line as you would in Linux, save and source it:

source ~/.bash_profile

3. Setting Environment Variables in Windows

In Windows, environment variables can be set through the Command Prompt or the System Properties GUI.

3.1. Using the Command Prompt

Open Command Prompt and set a temporary environment variable:

set MY_VAR=Hello World

To verify, use:

echo %MY_VAR%

3.2. Setting Permanent Variables

For permanent environment variables, search for Edit the system environment variables in the start menu. Click on Environment Variables, then under User variables or System variables, click New:

• Enter the Variable name and Variable value.

Click OK to save your changes.

4. Conclusion

By following this tutorial, you have learned how to set environment variables in Linux, macOS, and Windows. Environment variables are vital for configuring applications and managing system behavior. Explore additional methods and tools for handling environment variables to optimize your development environment!

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Dorian Kane

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