How to Open, Set, and Save Environment Variables (Windows, macOS, Linux)

🪟 How to Set Environment Variables in Windows

1. Open the Environment Variables Window

• Right-click the Start menu and select System (or press Windows Key + X and choose System).

• Click on Advanced system settings.

• Click the Environment Variables button.

2. Add a New Environment Variable

• Click New under the User variables or System variables section.

• Enter the Variable name and Variable value.

• Click OK.

3. Edit an Existing Environment Variable

• Select the variable you want to modify and click Edit.

• Update the Variable value and click OK.

4. Save and Apply

• Click OK on all open dialog windows to save your changes.

• Note: You must restart any currently open command prompts or applications for the changes to take effect.

🍎 How to Set Environment Variables in macOS

1. Open Terminal

• Go to Applications → Utilities → Terminal.

2. Set Temporary Environment Variables (Current Session Only)

Bash

export VARIABLE_NAME=value
# Example: export PATH=$PATH:/new/path

3. Set Permanent Environment Variables

• Open your shell profile file:

  • Bash shell: nano ~/.bash_profile or nano ~/.bashrc

  • Zsh shell (Default on newer macOS): nano ~/.zshrc

• Add your environment variable to the file:

export VARIABLE_NAME=value

*   Press `Ctrl + O` to save (WriteOut) and `Ctrl + X` to exit.
*   Apply the changes immediately by running:
    ```bash
source ~/.bash_profile  # or source ~/.zshrc

🐧 How to Set Environment Variables in Linux

1. Open Terminal

2. Set Temporary Environment Variables (Current Session Only)

Bash

export VARIABLE_NAME=value

3. Set Permanent Environment Variables

• User Level:

  • Open nano ~/.bashrc, nano ~/.bash_profile, or your active shell's configuration file.

  • Add export VARIABLE_NAME=value to the end of the file.

  • Save (Ctrl + O) and exit (Ctrl + X).

  • Apply the changes by running source ~/.bashrc (or the respective file).

• System Level:

  • Open the environment file using sudo: sudo nano /etc/environment or sudo nano /etc/profile.

  • Add the variable in the following format:

VARIABLE_NAME=value

    *   Save and exit.
    *   Restart the system or log out and log back in to apply the changes.

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### 🔍 How to Check Your Environment Variables

**Check a Specific Variable:**
*   **Windows (Command Prompt):**
    ```cmd
echo %VARIABLE_NAME%

• macOS / Linux (Terminal):

echo $VARIABLE_NAME

**View All Environment Variables:**
*   **Windows:**
    ```cmd
set

• macOS / Linux:

env

or

printenv