Emscripten scandir implementation

scandir.js

// NOTE implementation created in March 2013, may no longer work with Emscripten master
// http://pubs.opengroup.org/onlinepubs/9699919799/functions/scandir.html
// filter and compar are currently ignored
_scandir = function (dirp, namelist, filter, compar) {
	var dirPath = Pointer_stringify(dirp);
	var path = FS.analyzePath(dirPath);

	var files = [];

	if (path.error == 0) {
		var file;
		for (var name in path.object.contents) {
			file = path.object.contents[name];
			if (file.isFolder || file.isDevice || !file.read) {
				// Skip non-file or unreadable entries
				continue;
			}

			// No filter matching
			files.push(name);
		}

		// No compar support, just lexographic
		files.sort();

		var pNamelistAlloc = _malloc(4 * files.length);
		setValue(namelist, pNamelistAlloc, '*');

		var pDirent, nameBytes;
		for (var i = 0; i < files.length; i++) {
			pDirent = _malloc(268); // sizeof(struct dirent)
			pDName = pDirent + 11; // offset of d_name member (32-bit system)

			nameBytes = intArrayFromString(files[i]);
			for (var j = 0; j < nameBytes.length; j++) {
				setValue(pDName + j, nameBytes[j], 'i8');
			}

			setValue(pNamelistAlloc + (i * 4), pDirent, '*');
		}

		return files.length;
	}
	else {
		return -1;
	}
};