Replxx vs GNU readline: which is better for my project?

Choose Replxx if you need BSD licensing for proprietary software or want built-in syntax highlighting. GNU readline is more established with a larger ecosystem, but it's GPL-licensed, which may not suit all projects.

How to integrate Replxx into a C++ command-line tool?

After building with CMake, include the replxx.h header and link the library; implement callbacks for completion and hints as per the API, similar to readline but with added features like syntax highlighting.

Does Replxx support custom key bindings?

Yes, Replxx allows key binding customization through its API, but the README doesn't provide detailed examples, so you may need to refer to source code or experiment for complex mappings.

Replxx Windows setup with MinGW or Cygwin?

The README only specifies Visual Studio and CMake; while it might work with MinGW or Cygwin, you'll likely need to adapt the build process, as cross-platform support is primarily tested with native tools.

Can Replxx handle UTF-8 characters in all terminals?

Replxx is UTF-8 aware and tested on various terminals like xterm and Linux console, but compatibility issues might arise in non-standard environments, so verify with your specific setup.

How to persist command history in Replxx?

Replxx provides history management APIs; you need to implement file saving and loading manually in your application, as the library doesn't include automatic persistence out of the box.

Open-Awesome

replxx

NOASSERTIONC++

A BSD-licensed readline and libedit replacement with UTF-8 support, syntax highlighting, hints, and cross-platform compatibility.

GitHub

754 stars126 forks0 contributors

What is replxx?

Replxx is a BSD-licensed drop-in replacement for GNU readline and libedit that provides advanced line-editing features for command-line applications. It solves the licensing limitations of GPL-licensed readline while adding modern features like UTF-8 support and syntax highlighting. The library is designed to work across Linux, Windows, and macOS with minimal configuration.

Target Audience

C/C++ developers building command-line tools, REPLs, or interactive terminal applications that require sophisticated line editing. It's particularly valuable for projects that cannot use GPL-licensed readline due to licensing restrictions.

Value Proposition

Developers choose Replxx because it offers permissive BSD licensing while providing comparable functionality to readline, plus additional features like syntax highlighting and better UTF-8 support. Its zero-configuration approach and cross-platform compatibility make it an easy drop-in solution.

Overview

A readline and libedit replacement that supports UTF-8, syntax highlighting, hints and Windows and is BSD licensed.

Use Cases

Best For

Building proprietary command-line tools that need readline-like functionality
Creating cross-platform REPLs with syntax highlighting
Adding advanced line editing to embedded systems applications
Developing terminal applications requiring UTF-8 internationalization
Replacing GPL-licensed readline in BSD/Apache licensed projects
Implementing interactive debuggers or shells with hint systems

Not Ideal For

Projects that rely heavily on GNU readline's extensive plugin ecosystem or existing bash/readline scripts
Applications requiring graphical user interface (GUI) integration or web-based terminal emulators
Environments with extreme binary size constraints where even minimal library overhead is unacceptable
Teams needing extensive pre-built documentation or community support for niche use cases

Pros & Cons

Pros

Permissive BSD License

Allows use in proprietary and open-source projects without GPL restrictions, as emphasized in the project description for Apache2 or BSD licensed programs.

Cross-Platform Compatibility

Works on Linux, Windows, and macOS consoles with tested support for various terminals, ensuring broad usability for command-line applications.

Advanced Editing Features

Includes syntax highlighting and smart hints, providing real-time color coding and contextual suggestions beyond basic line editing.

Zero-Configuration Setup

Designed as a drop-in replacement for readline/libedit with no external dependencies, following a zero-configuration philosophy for easy integration.

Cons

Limited Ecosystem Support

Has a smaller community and fewer third-party extensions compared to GNU readline, which may limit advanced customization or bug fixes for edge cases.

Complex Windows Build

Requires CMake and Visual Studio for compilation, as shown in the build instructions, which can be more involved than package manager installations on other platforms.

Sparse Documentation

The README covers basics but lacks detailed API references or tutorials for advanced features like custom hint implementations, potentially increasing integration time.

Open Source Alternative To

replxx is an open-source alternative to the following products:

libedit

libedit is a command line editing library that provides line editing and history capabilities for interactive programs, similar to GNU Readline.

GNU Readline

GNU Readline is a library for command-line interfaces that provides line editing, history, and tab completion features for interactive programs.

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