Using async module's queue to avoid EMFILE with fs.readFile

readFile_queue.js

var fs = require("fs"),
    async = require("async");

 var q = async.queue(function (task, callback) {
      if (task.type == "file")
        fs.readFile(task.path, "utf8", callback);
 }, 250);

 dirFiles.forEach(function(path) {
          q.push({type: "file", path: path}, function (err, fileString) {
            if (err) {
              console.error(err);
              process.exit(1);
            }
          });
});