On macOS, you can set variables either globally for your user account or for a specific terminal session. The most common types of variables you might want to set are environment variables, which are used to configure various aspects of your system or applications. Here’s how you can set environment variables on macOS:

1. Setting an Environment Variable for a Terminal Session:

You can set an environment variable that will only be available for the duration of your current terminal session. Here’s how you can do it:

Open a Terminal window if you haven’t already. You can find Terminal in the Utilities folder within the Applications folder, or you can use Spotlight (Command + Space) to search for it.

To set a temporary environment variable for your current session, use the export command followed by the variable name and its value. For example, to set a variable named MY_VARIABLE with a value of example_value, you can do:

To check if the variable was set correctly, you can use the echo command:

2. Setting Environment Variables Globally:

If you want to set environment variables globally for your user account, you can add them to your shell profile file. On macOS, the default shell is usually Bash or Zsh. Here are the steps for both:

For Bash:

1. Open a Terminal window.

2. Edit your Bash profile file using a text editor like nano or vim. Replace nano with your preferred text editor:

3. Add the variable assignments in the file. For example:

4. Save the file (in nano, press Ctrl + O, then press Enter to confirm, and then press Ctrl + X to exit nano).

5. To apply the changes, either restart your Terminal or run the following command:

For Zsh (default in newer macOS versions):

1. Open a Terminal window.

2. Edit your Zsh profile file:

3. Add the variable assignments in the file, similar to Bash:

4. Save the file (in nano, press Ctrl + O, then press Enter to confirm, and then press Ctrl + X to exit nano).

5. To apply the changes, either restart your Terminal or run the following command:

Once you’ve set the environment variable globally, it will be available in all your terminal sessions until you remove or change it.

Remember to replace MY_VARIABLE and example_value with your actual variable name and value.

If you want to set system-wide environment variables that apply to all users, you would typically modify system configuration files, but doing so requires administrative privileges and should be approached with caution.