From Greg Morse on Fri, 20 Aug 1999
I enjoyed your little write up on bin vs /sbin etc. Is there somewhere that a file standard for non-linux systems exists? I have heard reference to a system V standard. How different is it from Linux?
There are many standards that relate to various facets of various forms of UNIX. However, I don't know of anything quite like the FHS for non-Linux systems.
I've heard that HP was looking at the Linux FHS as a possible model for their own HP-UX filesystem/layout specification. However that is an unsubstantiated rumor. Of course UNIX vendors are welcome to adopt the FHS and adapt their systems to match it. This would be of benefit to all UNIX and Linux users.
Also linux does not seem to have a /opt filesystem which is quite heavily used on my AIX and HPUX boxes. What is the Linux equivalent?
Linux does offer /opt. I usually make mine a symlink to /usr/local/opt. It is supposed to be for "applications binaries" (so things like KDE, WordPerfect, Applixware, and StarOffice would all go into the /opt hierarchy).
I would also appreciate it if you could go a bit deeper down the directory tree, explaining as you go. The whole unix directory structure is a mess and could really do with some xplanation as to what the common idoms are. Thank you.
Oooh! That would be a bit of a project. I don't think I have time for it this month (that two week trip to Japan and the demands of a full-time job are catching up to me). However, I'll leave this in my inbox until the end of the month in case I can spend a bit more time on it.
Note that there is a bit of a fractal quality to some parts of the typical/conventional Linux/UNIX directory tree.
For example we find bin, sbin, etc, lib and doc subdirectories under /usr/local/ which serve purposes that are analogous to the same directories that are found under / and/or under /usr. We commonly find a similar set of directories under /opt. It's also common to see users who put tmp, bin, src, and even lib subdirectories under their home directories.
Some of the same things can be seen under the /usr/X11R6 directory tree.
Beyond that quite a bit of the directory structure is specific to the packages that are installed.
Remember all of these are guidelines rather than strict rules. Sysadmins frequently will set things a bit differently --- though deviating too far from the expectations of their software will require quite a bit of programming and patching on their part.