ruster-env
> Bend the environment to your will.
A blazingly fast, session-persistent environment variable manager built specifically for Windows (PowerShell & CMD).
ruster-env injects variables directly into your current terminal session, making them available for every subsequent command you run—just like source .env on Linux.
Features
- Session Persistence: Variables stay loaded until you close the terminal.
- Windows First: Native support for PowerShell and Command Prompt.
- Safety Rails:
--no-overwrite protects your system PATH and other critical variables.
- Smart Interpolation: Supports variable expansion (e.g.,
URL=${HOST}:${PORT}).
- Clean Unload: One command to wipe project variables without restarting your shell.
- Zero Dependencies: Single binary, no Python/Node.js required.
Installation
Method 1: Winget (Recommended)
The easiest way to install is via the Windows Package Manager.
winget install ruster-env
Method 2: Manual (ZIP)
- Download the latest
ruster-env-windows-x64.zip from the Releases page.
- Extract the files (
ruster-core.exe and ruster-env.cmd) into a folder.
- Add that folder to your System PATH.
Shell Setup
If you installed via Winget or added the Manual folder to PATH, CMD users are ready to go. PowerShell users need a one-time profile update.
PowerShell
-
Run the init command to get the setup script for your specific installation path:
ruster-env init --shell powershell
-
Copy the output command. It will appear as follows:
Invoke-Expression (& "C:\Path\To\ruster-core.exe" init --shell wershell | Out-String)
-
Open your PowerShell profile:
notepad $PROFILE
-
Paste the copied command into the file and save it.
-
Restart PowerShell.
> [!TIP]
> Alternatively, run the copied command in your current powershell session to start using it immediately.
Command Prompt (CMD)
No extra setup required if the folder is in your PATH. The ruster-env.cmd wrapper handles everything automatically.
Usage
1. Load Variables
Injects variables from .env into your current session.
ruster-env load
- Result:
API_KEY is now available in your shell.
- Options:
--verbose: See exactly what is being set.--no-overwrite: Skips variables that already exist in your system (e.g., prevents hijacking USERNAME).
2. Set / Unset Single Variables
Quickly add or remove a single variable for the current session.
# Set a variable
ruster-env set DATA=Production
# Remove a variable
ruster-env unset DATA
3. Show Variables
Checks what is actually live in your system.
ruster-env show
-
List Mode: Prints all active system variables (hides internal Windows vars like =::).
-
Single Mode: Prints just the value (perfect for scripts).
# Copy DB URL to clipboard
ruster-env show DB_URL | clip
4. Run (Ephemeral)
Runs a single command with variables loaded, without modifying your current shell.
# Run a command with variables loaded from .env.test file (default=.env) isolated to that process
> ruster-env run --path .env.test -- python -c "import os; print(os.environ['WELCOME_MSG'])"
Hello World!
# Verify the variable did NOT leak into the current session
> ruster-env show WELCOME_MSG
Error: Variable 'WELCOME_MSG' is not set in the current environment.
5. Unload
Removes variables defined in your .env file from the session.
ruster-env unload
.env Syntax
ruster-env supports a robust syntax superset:
# Comments are supported
PORT=8080
HOST=localhost
# Quotes are stripped automatically
SECRET_KEY="super_secret_value"
SINGLE_QUOTES='works_too'
# Interpolation (References other variables)
# Order matters! Define base vars first.
DATABASE_URL=postgres://${HOST}:${PORT}/mydb