copy.js

// fs.copy(src,dst) && fs.copySync(src,dst)

var copy = function copy(src, dst, callback) {
	var self = this;
	
	if(!callback) {
		callback = function(){};
	}
	
	self.on('error', function(err) {
		callback(err);
	});

	self.on('validations', function() {
		path.exists(src, function(exists) {
			if(!exists) {
				self.emit('error', new Error(src + ' does not exists. Nothing to be copied'));
				return;
			}
			
			fs.stat(src, function(err, stat) {
				if(err) {
					self.emit('error', err);
					return;
				}
				
				if(stat.isDirectory()) {
					self.emit('error', new Error(src + ' is a directory. It must be a file'));
					return;
				}
				
				if(src == dst) {
					self.emit('error', new Error(src + ' and ' + dst + 'are identical'));
					return;
				}
				
				//Go!
				self.emit('open_infd');
			});
		});
	});
	
	self.on('open_infd', function() {
		fs.open(src, 'r', function(err, infd) {
			if(err) {
				self.emit('error', err);
				return;	
			}
			self.emit('open_outfd', infd);
		});
	});
	
	self.on('open_outfd', function(infd) {
		fs.open(dst, 'w', function(err, outfd) {
			if(err) {
				self.emit('error', err);
				return;	
			}
			self.emit('sendfile', infd, outfd);
		});
	});
	
	self.on('sendfile', function(infd, outfd) {
		fs.fstat(infd, function(err, stat) {
			if(err) {
				self.emit('error', err);
				return;
			}
			fs.sendfile(outfd, infd, 0, stat.size, function() {
				self.emit('close_fds', infd, outfd);
				callback();
			});
		});
	});

	self.on('close_fds', function(infd, outfd) {
		fs.close(infd, function(err) {
			if(err) {
				self.emit('error', err);				
			}
		});
		
		fs.close(outfd, function(err) {
			if(err) {
				self.emit('error', err);				
			}
		});
	});
	
	//Start here
	self.emit('validations');
};
sys.inherits(copy, events.EventEmitter);

fs.copy = function(src, dst, callback) {
  return new copy(src, dst, callback);
};

fs.copySync = function copySync(src, dst) {
	if(!path.existsSync(src)) {
		throw new Error(src + ' does not exists. Nothing to be copied');
	}
	
	if(fs.statSync(src).isDirectory()) {
		throw new Error(src + ' is a directory. It must be a file');
	}
	
	if(src == dst) {
		throw new Error(src + ' and ' + dst + 'are identical');
	}

	var infd = fs.openSync(src, 'r');
	var size = fs.fstatSync(infd).size;
	var outfd = fs.openSync(dst, 'w');
	
	fs.sendfileSync(outfd, infd, 0, size);
	
	fs.close(infd);
	fs.close(outfd);
};