change-watcher.js

/*
 * Runs pdflatex and bibtex on filechange.
 * This assumes you have main.tex
 * in the folder where command is run.
 *
 * Usage: node change-wathcer.js somedir &
*/
'use strict';
var fs = require('fs'),
    exec = require('child_process').exec,
    dir = process.argv[2],
    command = "./compile.sh";
fs.watch(dir, function(event, filename) {
    exec(command, function(err, stdout, stderr) {
        console.log(stdout);
    });
});

compile.sh

#!/bin/bash
pdflatex main.tex
bibtex main.aux
pdflatex main.tex
pdflatex main.tex