Macos

While developing Valence, an input-only Android VNC client for remote controlling a computer, I've encountered several notable quirks in Apple Remote Desktop, Mac OS's built-in VNC server. Apple Remote Desktop (ARD) is based on VNC, a system developed in the late 1990's for controlling a remote computer, and its Remote Framebuffer (RFB) protocol. Generally, standard VNC clients can interoperate with ARD. An ARD server reports use of version "3.889" of the RFB protocol, which isn't a real version of RFB, but this version number can be used by clients to know that they are talking to an ARD server and not a conventional VNC server.

While using Mac OS, I've been missing the handy Linux inotifywait utility—it's a simple program to use the Linux inotify facility to wait on certain file events. I sometimes write scripts that use inotifywait to automatically launch programs when files are changed. For instance, I can have a script automatically compile a program whenever I save the source file in the editor.

It turns out that Mac OS and other recent BSD operating systems have a similar kernel facility called kqueue, and it was really easy to whip up a small program to block until an event occurs on a file. My filewait program is linked below, and can be used in scripts such as this one: