Monitoring Files With GCD Being Edited With A Text Editor

example.m

- (void)watchConfigFile:(NSString*)path;
{
	dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
	int fildes = open([path UTF8String], O_EVTONLY);

    __block typeof(self) blockSelf = self;
	__block dispatch_source_t source = dispatch_source_create(DISPATCH_SOURCE_TYPE_VNODE,fildes, 
															  DISPATCH_VNODE_DELETE | DISPATCH_VNODE_WRITE | DISPATCH_VNODE_EXTEND | DISPATCH_VNODE_ATTRIB | DISPATCH_VNODE_LINK | DISPATCH_VNODE_RENAME | DISPATCH_VNODE_REVOKE,
															  queue);
	dispatch_source_set_event_handler(source, ^
	{
		unsigned long flags = dispatch_source_get_data(source);
		if(flags & DISPATCH_VNODE_DELETE)
		{
			dispatch_source_cancel(source);
			[blockSelf watchStyleSheet:path];
		}
		// Reload config file
	});
	dispatch_source_set_cancel_handler(source, ^(void) 
	{
		close(fildes);
	});
	dispatch_resume(source);
}