Envy Merge

envy-merge is a CLI tool to intelligently merge multiple .env files while ensuring that a priority file (if provided) takes precedence over all others.

Features

• Merges multiple .env files into a single output.
• Respects a priority file (if provided), ensuring its variables are never overwritten.
• Later files overwrite earlier ones unless the variable exists in the priority file.
• Supports output redirection to a file or prints to stdout.
• Dry-run mode to preview merged output without saving.

Installation

Ensure you have Rust installed. If not, install it via Rustup.

Clone the repository and navigate to the project folder:

git clone https://github.com/morlim/envy-merge.git
cd envy-merge

Then, build the project:

cargo build --release

Usage

Run the CLI tool with multiple .env files:

./target/release/envy-merge file1.env file2.env

Options

USAGE:
    envy-merge [OPTIONS] <FILES>...

ARGS:
    <FILES>...    List of .env files to merge (at least 2 required)

OPTIONS:
    -p, --priority <FILE>    File to take priority in case of conflicts
    -o, --output <FILE>      Output .env file (default: stdout)
    -d, --dry-run            Show merged output without writing to a file
    -h, --help               Show help message
    -V, --version            Show version

Example

Input Files

priority.env

DB_HOST=secure-db
DB_PORT=5432
API_KEY=supersecret

file1.env

DB_HOST=localhost
DB_PORT=3306
DEBUG=false

file2.env

API_KEY=publickey
LOG_LEVEL=info

Merging with Priority File

./target/release/envy-merge -p priority.env file1.env file2.env

Output

DB_HOST=secure-db  # Taken from priority file (CANNOT be overwritten)
DB_PORT=5432       # Taken from priority file (CANNOT be overwritten)
API_KEY=supersecret # Taken from priority file (CANNOT be overwritten)
DEBUG=false        # From file1.env
LOG_LEVEL=info     # From file2.env

Dry Run Mode

./target/release/envy-merge -d file1.env file2.env

This will print the merged output without saving it to a file.

Saving to a File

./target/release/envy-merge -o merged.env file1.env file2.env

Error Handling

• If a file cannot be read, an error message is displayed, and the process exits with a non-zero code.
• Uses anyhow for robust error handling.

Contributing

Feel free to open issues or submit pull requests to improve functionality!

License

This project is licensed under the MIT License.