Recently, I had a need to know if any files or folders had been modified or created on an HFS+ volume in the past N seconds. There are many ways you could generate this type of information on Mac OS X.
To begin with, you could try asking Spotlight.
Besides Spotlight, Mac OS X has a rich [...]

I discovered a bug in hfsdebug. It causes hfsdebug to crash while printing Access Control Entry (ACE) details for certain files or folders. For example, consider the standard ~/Library/Preferences/ folder on Leopard.

$ ls -lde ~/Library/Preferences
drwx——@ 167 singh staff … /Users/singh/Library/Preferences
0: group:everyone deny delete

This folder has an ACE for the group everyone. In particular, [...]

A while ago, I wrote about procfs for Mac OS X, a MacFUSE-based file system. Subsequently, I added more cool features to my procfs implementation. Recently, I had reason to demonstrate procfs again and realized that I needed still more cool features. That need led to GrabFS.

In a pinch, GrabFS is a file system that [...]

I found some time today to make a certain feature of HFSDebug work on Leopard. The new version is available for download here. The new version should run on both Leopard and Tiger, but there are no visible changes whatsoever for Tiger users.
If you use HFSDebug, you might have realized that the -m option doesn’t [...]

A few weeks ago, I released as open source a MacFUSE-based process file system for Mac OS X.
I recently added several new features to this procfs implementation. Some of these features are "cool" in that they put a new twist on certain types of visual information.
For example, there’s a folder /proc/system/hardware/displays/ that contains a subfolder [...]

On the right, we have a PowerMac G5.

On the left, we have academic papers and author-prepared notes that were used in the creation of “Mac OS X Internals“.

(Recycled paper used when possible. In particular, the book is printed on recycled paper.)

When I replayed this interview of mine, I found a syntax error in one of the things I said.
When the interviewer talks about X Window programming on Mac OS X, I said that the communication between “your program and the X server” is specific to Mac OS X. I meant to say the communication beween [...]

Let us try to make them a little cooler on Mac OS X.

I will be speaking at the following venues in the near future:

Chaos Communication Congress, Berlin, Germany (December 29, 2006)
Macworld Conference & Expo, San Francisco, USA (January 11, 2007)

A discussion on how Apple’s binary protection works in the x86 version of Mac OS X:
Understanding Apple’s Binary Protection in Mac OS X

A discussion on customizing kernel panic graphical dialogs and testing such customizations…
A New Screen of Death for Mac OS X

I was told by my publisher that there was a long back-order queue for the book because they had sold out the first printing. It took a while to print the next lot. Strictly speaking, the next printing has been available for almost two weeks now, but the Addison-Wesley page for the book has just [...]

Some people can read really fast, as the following link shows:
A Quick Read of "Mac OS X Internals"”

Something to look at:
Mac OS X Internals Flyer

FYI:
I will be holding a Mac OS X Internals workshop on Thursday, August 10th, 12:00 noon at the San Francisco Apple Store. This is a part of Apple’s “WWDC: Meet the Authors” line of Apple-store events.
More details here (look for the August 10 calendar entry).

The very first chapter I wrote for Mac OS X Internals: A Systems Approach was the “history” chapter. My goal was to create a comprehensive and detailed book. I deemed it important for the reader to understand the long and eventful journey toward Mac OS X. Therefore, I wrote the chapter as a technical history [...]