filefuser

This Rust tool aggregates text files into a single EML archive. It scans a specified directory for files matching user-defined glob patterns, extracts metadata to determine if they are valid text files, and then combines them into a MIME multipart message complete with generated headers and boundaries.

This tool is great for aggregating source code into a single file for easy pasting into a large language model.

Installation

On MacOS or Linux you can install filefuser using Homebrew:

brew install perarneng/tap/filefuser

If you are on Windows or use other package manager then download appropriate binary from the release page.

Building the Project

To compile the project, you can use Cargo, Rust's build system and package manager. In your project's root directory, run the following command for a standard (debug) build:

cargo build

For a release build, which optimizes the binary for production, use:

cargo build --release

To run the test suite and ensure that everything is working as expected, simply execute:

cargo test

Example Usage

To use filefuser, you can run it from the command line with the following syntax:

filefuser --file archive.eml --patterns "*.txt,*.rs" --dir ./src

This command will scan the ./src directory for files with the .txt or .rs extension, and then combine them into a single EML archive named archive.eml in the current directory.

Architecture

This project is designed as a modular, concurrent command‐line tool that aggregates text files into a single MIME multipart EML archive. Its architecture is divided into distinct layers: the CLI and configuration layer parses command-line arguments using the Clap library, ensuring that file paths, search directories, and glob patterns are validated and correctly set up. The directory scanning module recursively walks the file system, employing regex-based glob matching to efficiently identify candidate files. Once located, the file data extraction layer leverages asynchronous operations with Tokio to concurrently analyze files, extract metadata such as file size and content type (text or binary), and gracefully capture errors without halting overall processing. Finally, the archiving layer encapsulates the logic for constructing the EML archive—it dynamically generates MIME headers and boundaries, reads each text file's content, and assembles everything into a well-formed EML file. Throughout the system, dedicated logging and utility modules support detailed error reporting and streamlined file operations, resulting in a robust, maintainable, and high-performance Rust application.

References

• RFC 5322 - Internet Message Format
  Defines the structure of email messages, including headers such as Date, From, To, Subject, and MIME-Version.
• RFC 2045 - Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies
  Specifies the syntax for formatting message bodies to include various types of data in emails.
• RFC 2046 - Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types
  Defines the media type system used in MIME, detailing how to classify the content contained within email messages.