Variables

Defining Variables

name = "Jake";
version = "1.0.0";
build_dir = "dist";

Using Variables

Use {{variable}} syntax in commands:

greeting = "Hello"
target = "World"

task greet:
    echo "{{greeting}}, {{target}}!"

Output: Hello, World!

Variable Scope

Variables are global and available to all recipes:

project = "myapp"

task build:
    echo "Building {{project}}"

task test:
    echo "Testing {{project}}"

Variable Precedence

When the same variable name is defined in multiple places, the following precedence applies (highest to lowest):

1. Recipe parameters (passed via CLI: jake build env=prod)
2. Environment variables (loaded via @dotenv or from shell)
3. Jakefile variables (defined with = assignment)

This means @dotenv should appear before variable assignments to allow .env files to override defaults:

@dotenv                    # Load .env first
PORT = "3000"              # Default value (overridden by .env if PORT is set there)

task serve:
    echo "Running on port {{PORT}}"

With .env containing PORT=8080, the task outputs: Running on port 8080

Without .env or if PORT is not set, it uses the default: Running on port 3000

Environment Variables

Loading .env Files

@dotenv                    # Load .env
@dotenv ".env.local"       # Load specific file

Files are loaded in order; later files override earlier ones.

Exporting Variables

@export NODE_ENV=production
@export DEBUG=false

Exported variables are passed to all subprocess commands.

Using in Commands

Use $VAR or ${VAR} syntax:

task show:
    echo "Node: $NODE_ENV"
    echo "Debug: ${DEBUG}"

.env File Format

# Database settings
DATABASE_URL=postgres://localhost/myapp
DB_POOL_SIZE=10

# API Keys (use quotes for special chars)
API_KEY="abc123!@#"

# Empty values
EMPTY_VAR=

# Escape sequences
MULTILINE=line1\nline2
WINDOWS_PATH=C:\\Users\\Name

Supported escapes: \n, \t, \r, \\, \", \', \$

Requiring Variables

Validate required environment variables:

@require API_KEY DATABASE_URL

task deploy:
    echo "Deploying with $API_KEY"

Jake exits with an error if any required variable is missing.