---
tags:
  - macOS
  - Tahoe
  - zsh
  - environment-variables
  - terminal
title: Managing Environment Variables in macOS Tahoe
---

# Managing Environment Variables in macOS Tahoe

Environment variables are dynamic values that affect the processes or programs on a computer. In macOS Tahoe, managing these variables is a key skill for terminal usage and scripting.

## Viewing Environment Variables

To see a list of all current environment variables, use the `printenv` command in the terminal:

```zsh
printenv
```

To view the value of a specific variable, use `echo` with the variable name prefixed by `$`:

```zsh
echo $HOME
echo $USER
```

## Setting Variables Temporarily

You can set a variable for the current terminal session using the `export` command. This variable will disappear once you close the terminal window.

```zsh
export MY_VAR="Hello World"
echo $MY_VAR
```

## Setting Variables Permanently

To make a variable persist across all terminal sessions, you need to add it to your Zsh configuration file (`.zshrc`).

1.  Open your `.zshrc` file (see Advanced Zsh Configuration in macOS Tahoe for details on editing this file).
2.  Add the export line to the bottom of the file:

```zsh
export API_KEY="123456789"
```

3.  Save the file and reload the configuration:

```zsh
source ~/.zshrc
```

## The PATH Variable

The most commonly modified environment variable is `PATH`. It tells the shell where to look for executable commands.

To add a new directory to your `PATH` (for example, a custom `bin` folder in your home directory), add this to your `.zshrc`:

```zsh
export PATH="$HOME/bin:$PATH"
```

This appends your custom folder to the existing path, ensuring you can run scripts located there from anywhere. 

## Project-Specific Variables with .env 

For development projects, it is common practice to store environment variables in a file named .env within the project root. This keeps configuration separate from code. 

A typical .env file looks like this: 

`zsh +DB_HOST=localhost +DB_USER=root +API_SECRET=mysecretkey`

To load these variables into your current shell session, you can use the following command: 

`zsh +export $(grep -v '^#' .env | xargs)`

 Note: Always add .env to your .gitignore file to prevent secrets from being committed to version control (see Managing Git Repositories on macOS Tahoe).