Mac OS X Panther for Unix Geeks, Second Edition

Appendix A. The Mac OS X Filesystem

If you do an ls -a / on your Mac OS X box, you will see some familiar things, such as /etc and /var, but you will also notice some unfamiliar things, such as /TheVolumeSettingsFolder, /Library, and /Documents. The Mac OS X filesystem contains traces of Unix, NeXTSTEP, and Mac OS 9. This appendix describes the contents of important directories. The tables in this chapter list directory entries (directories are denoted with a trailing slash) and provide a description of each file or directory.

Files and Directories

Table A-1 describes the files and directories you may find in your root directory. The remaining tables in this chapter describe significant subdirectories.

Table A-1. Mac OS X’s root directory

File or directory	Description
.DS_Store	Contains Finder settings, such as icon location and window size. The file will appear in any directory that you’ve viewed with the Finder.
.hidden	Contains a list of files that should be invisible to the Finder.
.hotfiles.btree	Used by Panther’s Hot File Adaptive Clustering, which automatically defragments frequently accessed files that are under 20 MB in size.
.Trashes/	Contains files that have been dragged to the Trash. On a boot volume, such files are stored in ~/.Trash. On a non-boot volume, these files are in /.Trashes/uid/.
.vol/	Maps HFS+ file IDs to files. If you know a file’s ID, you can open it using /.vol/id.
Applications/	Holds all your Mac OS X applications. Its Utilities ...