websocketd is a command-line tool that wraps existing programs to expose them as WebSocket servers.
The tool solves the problem of building WebSocket-capable applications without requiring developers to learn networking libraries. It works by listening for WebSocket connections on a specified port, forking a child process for each connection, and piping messages between the WebSocket client and the process's standard input and output streams. Text sent from the client is written to the process's STDIN with a newline appended, and any output the process writes to STDOUT is sent back as a WebSocket message when a newline is encountered. This approach lets developers write server logic in any language that supports reading from STDIN and writing to STDOUT.
The tool suits projects where you have an existing command-line program or script that you want to expose over WebSocket without modification. It works well for simple, line-oriented protocols where bidirectional communication can be expressed through newline-delimited messages. This is particularly valuable for rapid prototyping or for integrating legacy command-line tools into web applications. The README emphasizes that the same program works identically when run from the command line or wrapped as a WebSocket server, eliminating the need to maintain separate implementations.
Issues and pull requests in the project often wait weeks or longer for a first response. Work in the issue tracker is dominated by documentation, discussion, and feature requests.
