I run this JavaScript every minute to copy files from a private folder to a public-facing server.

copyRiverFiles.js

//By Dave Winer, May 12, 2015.

//I use this script to copy the only files that River4 produces that have to be publicly accessible.

//It only copies if the dest file doesn't exist or if the content of the files has changed.

//I use Noderunner to run it once every minute: https://github.com/scripting/noderunner


var sourcefolder = "/root/river4data/rivers/";
var destfolder = "../pagepark/domains/hello.com/rivers/";
var urldestfoler = "http://hello.com/rivers/";
console.log ("Hello from copyriverfiles.js");
function copyOneFile (fname) {
	var fsource = sourcefolder + fname, fdest = destfolder + fname;
	console.log ("copyRiverFiles.js: fname == " + fname + ", list [i] == " + list [i]);
	fs.readFile (fsource, function (err, jsontext) {
		if (err) {
			console.log ("copyriverfiles.js: error reading file == " + fsource + ", message == " + err.message);
			}
		else {
			fs.readFile (fdest, function (err, jsontextFromDest) {
				if (err || (jsontext.toString () != jsontextFromDest.toString ())) {
					fs.writeFile (fdest, jsontext, function (err) {
						if (err) {
							console.log ("copyriverfiles.js: error writing file == " + fdest + ", message == " + err.message);
							}
						else {
							console.log ("copyriverfiles.js: copied == " + urldestfoler + fname);
							}
						});
					}
				});
			}
		});
	}
fs.readdir (sourcefolder, function (err, list) {
	if (err) {
		console.log ("copyRiverFiles.js: error == " + err.message);
		}
	else {
		for (var i = 0; i < list.length; i++) {
			copyOneFile (list [i]);
			}
		}
	});

Useful! If you pipe the files, it'll be a bit faster and memory efficient. Also, is this on a cron job? If it is you could use a simple setInterval to run every minute and not have to worry about V8 spinning up.

I use Noderunner to run it once a minute.

https://github.com/scripting/noderunner

grunt --watch
would do it at once and only those changed
noderunner would still be a node script (grunt also)

Bruno, I don't understand what you're saying. I'm sure if I typed grunt --watch at the command line it would not do all that this script does. Maybe somehow magically it can read my mind? ;-)

This script only copies files that changed.