AmigaOS filesystem layout

[AmigaFreak]

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.

[danbeaver]

For which OS (1.3, 3.1/3.9, or 4.1)?

Define "Layout."  

"Thomas Rapp" on the forums is an expert, see: "http://thomas-rapp.homepage.t-online.de/index.html"

Also search Google: http://en.wikipedia.org/wiki/Amiga_Fast_File_System

[guest11527]

Double post - ignore.

[guest11527]

Is there a book like that, or something on-line I can read?

There is the Bantam Books "Amiga Dos Manual" which contains this information, and there is the "Guru Book" by Ralph Babel. Of the two books, the latter is more recommended, though the former is the original reference.

[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!

[pVC]

S - Startup - startup scripts

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

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!

Yes and you can also add locations to the assigns. For example if you want to keep your SYS:Libs/ directory clean only containing the libraries which come with the OS, and you want to have 3rd party libraries in some other dir.. for example in SYS:UserLibs. You can add it with "Assign Libs: SYS:UserLibs ADD" command. Then the library to be opened from the Libs: will be looked from the both SYS:Libs/ and SYS:UserLibs/ paths.

[kolla]

This what MorphOS does in a very neat way. All the typical directories are pretty much empty, for example SYS:Libs, but LIBS: is assigned to SYS:Libs MOSSYS:Libs, and the lattet comtains all of MorphOS native libraries. Any libraries installed by programs or user, goes to SYS:Libs (since it is first in path of the Libs: assign), and libs in SYS:Libs will also be loaded before equally named libs in MOSSYS:Libs.

And all these directories came from TRIPOS btw.

[Oldsmobile_Mike]

Yes and you can also add locations to the assigns. For example if you want to keep your SYS:Libs/ directory clean only containing the libraries which come with the OS, and you want to have 3rd party libraries in some other dir.. for example in SYS:UserLibs. You can add it with "Assign Libs: SYS:UserLibs ADD" command. Then the library to be opened from the Libs: will be looked from the both SYS:Libs/ and SYS:UserLibs/ paths.

And this is why AmigaOS is so great, even 30 years later.  

[Tenacious]

And this is why AmigaOS is so great, even 30 years later.  

Agreed!  Actually 1 of many reasons.

You didn't mention which Amiga or version of the OS you have.  If you still have the books that came with an OS1.3 Amiga, the small book "Enhancer Software" has a complete list of all the traditional directories and all the files they contain on the standard disks (starting at B-1).  As already said, most of the AmigaDos manuals explain this well, too.

One of my favorite references is Rob Peck's "The Amiga Companion".  It is clearly written and available online as a PDF.

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

[broadblues]

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!

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.

[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!

[itix]

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.

If SYS:C is missing would AmigaOS look Startup-Sequence from the root?

[guest11527]

And all these directories came from TRIPOS btw.

Actually, no. Only the one-letter directories are tripos. L: for "Libraries", this is were Tripos keeps its "Library stuff", we call it "Handlers" today. "S:" for scripts, "C:" for commands.  DEVS: and LIBS: are exec/Sassenrath names that came in through ramlib. T: is also a Tripos name. FONTS: came a lot later.

[Matt_H]

For reference, here is the Tripos manual. I paged through it a number of years ago. It's a fascinating read, especially for me, since I think the Amiga's logical, human-readable file hierarchy is one of its greatest assets - but it comes almost verbatim from an older system!

[pVC]

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.

Some people have made boot disks etc with reassigned system assigns, and I haven't heard any complaints of them. So I'd guess it should work that you first remove S: assign, and then assign it elsewhere. Although I don't remember trying it myself, but nobody (at least programmers) should never use fixed paths in these situations... probably at least most of the stuff would work happily.

Maybe only the startup-sequence has to be where kickstart looks it at first place, but then you can reassign other dirs first thing in it...