AmigaOS filesystem layout

[chris]

Hey everyone,

I'm looking for information on the filesystem layout on AmigaOS. What is where, why a particular file is in that place, Just general directory layout... Is there a book like that, or something on-line I can read?

I'm just kinda curious about the FS layout of the Amiga... I've used UNIX systems quite a bit and I'm used to the filesystem layout.. /bin , /usr etc... but even though I have used my fair share of Amigas, I never really opened up CLI to dig around in the actual filesystem beyond Workbench's windows.

Briefly, the system partition is something like this (from memory - so may well have missed something):

C - Commands - executable commands.
Classes - BOOPSI Classes - gadget classes, datatypes, etc
Devs - Devices - Device drivers.  Also sub-divided into Printers (printer drivers), DataTypes (datatypes descriptors, not sure why these are in Devs though), and some other things I forget.
Fonts - Fonts - Fonts!
L - Filesystem Handlers (named Libraries due to TripOS legacy).  OS4 also has some charset information here for some reason (which ought to be in LOCALE: )
Locale - Localisation stuff - translations, country data, help files, etc
Libs - Libraries - Shared libraries
Prefs - Preferences - WB prefs programs.  Also contains Env-Archive, which is where permanent prefs and environmental variables are stored.
S - Startup - startup scripts
SObjs - Shared Objects - OS4 only, Linux-style shared libraries (.so)
System - System programs - Commands like Format which are required by WB
Utilities - Utilities - Dumping ground for software which comes with the OS
Tools - Tools - Dumping ground for software which traditionally comes on the Extras disk

The actual directory names don't really matter that much - AmigaOS references them all by assigns - DEVS:, C:, LIBS: etc.  I haven't tried renaming and manually setting the assigns to the new locations, but in theory that should work!

[chris]

I read that it's originally from "Sequence" word, and you'll put all kinds of scripts there, not just startup scripts.

Yes, I think you're right.

And all these directories came from TRIPOS btw.

Only the single-letter ones AFAIK.

"..L - Filesystem Handlers (named Libraries due to TripOS legacy).."  I used to wonder about how L got its name.

I only found out fairly recently, when somebody posted a link to the TripOS manual.

I'm not so convinced of that. Yes you can add paths to the assigns, and even remove and reassign them else where, but if the standard dirs aren't there, you might have trouble booting in the first place, to run the script that does that.

The absense of SYS:S and SYS:C in particular may cause a headache.

Yes, fair point.  It was more a thought exercise than something I'd expect anybody to try!

[chris]

Check out page 1-14 of the Tripos manual:
[...]
DEVS: My.Boot.Disk:devs

I wonder why that's DEVS: and not D:. I thought it had been added post-TripOS but obviously not.

[chris]

Maybe they should have put the Classes in LIBS: though as the gadgets and datatypes are libraries.

Well, SYS:Classes is multi-assigned to LIBS: so it is really.