gistfile1.js

var sys = require('sys')
  , http = require("http")
  , spawn = require('child_process').spawn;
  
var filename = process.ARGV[2];

if (!filename){
  sys.puts("Usage: node watcher.js filename");
  process.exit(1);
} else {
  var tail = spawn("tail", ["-f", filename]);
  sys.puts("start tailing");

  http.createServer(function(req, res) {
    tail.stdout.addListener('data', function(data) {
      res.writeHead(200, {
          'Content-Length': data.length,
          'Content-Type': 'text/plain'
      });
    
      sys.puts("add listener called in server");
      res.write(data);
    
      // you can actually do res.end(data);
      res.end();
    });
  }).listen(8080);
}