how brain dead is AIX?

[Richard M. Mathews]

steve%ibmsupt at uunet.uu.net (Steve DeJarnett) writes:

>>I have a copy of 'IBM RISC System/6000 Software Offerings Overview' brochure.
>>I am a little worried about two of the statements made: 
>>
>>A) When there are conflicts, they are resolved with priority 1) POSIX
>>	2) SVID 3) 4.3 BSD 4) AIX/RT. (p. 3). 
>>
>>   I gather that AIX is System V kernel with the Berkeley stuff emulated.
>>   So, do you get:
>>     1) the System V file system or the 'Berkeley Fast File System'

>	Neither.  You get the new Journaled File System (JFS).

Since the question refers the the RISC System/6000, this answer is
correct.  It is worth pointing out, however, that implementation details
differ between the various AIX platforms even though the user interface
is all based on the same Family Definition.  On the PS/2 and 370, you
get a kernel (built from a common source!) which evolved over many
years from a BSD 4.1 kernel, had Locus Operating System features added,
then SVR2, then 4.2, and so on.  Neither BSD nor System V features are
emulated.  System V and BSD features are each integral parts of a well
merged system (IMHO).  The same sort of statement could probably be made
about the 6000 kernel, but I know less about its history.

The file system on AIX/370 and AIX PS/2 has features such as long names
and symbolic links, but in most respects it is more similar to the System
V file system.  It really isn't either.  Changes have also been made to
support replication and other features of TCF.

>>     2) streams or sockets

>	Sockets.

Same answer for AIX/370 and AIX PS/2.

>>     3) job control (control-Z)

>	You bet.

Same answer for AIX/370 and AIX PS/2.

>>     4) AT&T or Berkeley terminal device driver.

>	Actually, what you get is a POSIX line discipline and a BSD line
>discipline, although almost the entire BSD line discipline was duplicated in
>the POSIX (default) line discipline, so unless you're using a Hazeltine 
>terminal with no '~', you'll probably never notice.  Also, be aware that in
>4.4 (or whatever it will be called), CSRG has said that they will be shipping
>a POSIX-compliant line discipline, and will be deprecating the BSD line
>discipline.  I believe Sun is already shipping a POSIX line discipline in SunOS.

On AIX 370 and AIX PS2/2 (version 1.2 of each) you get a terminal driver
which accepts BSD and SysV ioctls and which I believe passes POSIX tests.

>>B) 'Most 4.3 BSD commands, system calls, and library routines are supported.'
>> 	(p.3) and features include a '4.3 BSD compatibility library'.  (p.5)
>>
>>  Ok, what is missing? 

>	Briefly:

>Libraries: getmntent, addmntent, etc. (the *mntent functions), endusershell,
>	getdiskbyname, getusershell, ns_addr, ns_ntoa, quota, setquota,
>	setusershell, tell, x3wind.

>Commands:  arff, bad144, badsect, dcheck, diskpart, drtest, error, edquota,
>	gcore, kgmon, lpc, mset, quot, quotacheck, quotaoff, quotaon, 
>	repquota, systat, trsp, and XNSrouted.

I'm sure the list is a bit different for AIX/370 and AIX PS/2, but I can't
give details.  We do have BSD quotas.  We do have the "quot" command.  We
do have {get,set,end}usershell.  We may be missing some things not listed
above.  I just don't have the data available right now (I'm at home).

Note that the emphasis in the above is on the differences between AIX
on different platforms.  Despite this, I would still say they are more
like each other than are any other 2 implementations of Unix systems.

Disclaimer: I only speak for myself.  In addition, all statements here
were made from memory, and my memory has been known to be faulty at times:-)

Richard M. Mathews			D efend
Locus Computing Corporation		 E stonian-Latvian-Lithuanian
richard at locus.com			  I ndependence
lcc!richard at seas.ucla.edu
...!{uunet|ucla-se|turnkey}!lcc!richard