Simon Willison’s Weblog

Live htop. Neat, simplest-thing-that-could-possibly-work implementation of a tool that continually pipes the output of the htop command to a browser over a WebSocket. The htopgen.sh scripts loops every 2 seconds, runs htop, pipes it through a utility to convert the output to HTML and writes that to a file. Then the server.js Node.js script watches for changes to that file and pipes the entire file contents to the browser via socket.io. The index.html page in the browser subscribes to the WebSocket and updates the entire page using innerHTML every time it receives an event.