gfslogger v1.0 This program subscribes to Mac OS X 10.4 (& up) fsevents and prints to standard output all filesystem events it receives. The fsevents api is the same used by Spotlight to receive file system changes immediately as they occur without constant polling. It is currently private and undocumented by Apple. This program should work on Mac OS X 10.4 "Tiger" (& up) and it has only been tested with the author's C compiler. YMMV. There is one major caveat to be concerned with (from kernelthread.com): The interface that fslogger uses is private to Apple. Currently, there is a caveat regarding th use of this interface by third parties (including fslogger). While the change notification interfac supports multiple clients, there is a single kernel buffer for holding events that are to be delivered to one or more subscribers, with the primary subscriber being Spotlight. Now, the kernel must hold events until it has notified all subscribers that are interested in them. Since there is a single buffer, a slow subscriber can cause it to overflow. If this happens, events will be dropped for all subscribers, including Spotlight. Consequently, Spotlight may need to look at the entire volume to determine "what changed". fslogger is meant to be a learning tool. If you use it, you must understand the aforementioned caveat. If you cause heavy enough file system activity (what's "heavy" will vary greatly, depending on your system and its currently available resources), both fslogger and Spotlight may miss events, causing Spotlight to spend some extra time looking at your volume. Note that Spotlight will not reindex the entire volume — it will only look for the changes that it missed. An example of a typically heavy file system activity (that may quite possibly cause events to b dropped) is unpacking a giant tarball. Finally, if events are missed, fslogger will indicate that event (missing events is an event itself). fsevents.h is licensed under the APSL and owned by Apple. gfslogger.c is licensed under the GPL and owned by Me (Rian Hunter). Rian Hunter rian@alum.mit.edu
