Job control

Chuck Karish karish at forel.stanford.edu
Fri Dec 1 12:09:14 AEST 1989


In article <22902 at gryphon.COM> oleg at gryphon.COM (Oleg Kiselev) wrote:
>In article <7106 at portia.Stanford.EDU> karish at forel.stanford.edu (Chuck Karish) writes:
>>Oleg Kiselev seems to be complaining about something else, that the
>>AIX-PS/2 user interface is different from the 4.3 BSD user interface.
>
>You misunderstood.  I commented on AIX PS/2 being very much BSD-like both on
>the user interface level and on the library services level and on the system
>call level (unless POSIX compliance required a change).  RT AIX which I had
>used did not offer the BSD feel at least on the user level.

This isn't what you said the other day.  You said that AIX-PS/2 was becomming
more RT-like, and that you didn't like it.

POSIX 1003.1 compliance involves supporting a BSD-like signalling
mechanism, a SysV-like terminal IO subsystem, and a number of
special-purpose functions instead of ioctls with varying numbers and
types of arguments, which were difficult or impossible to rationalize
with ANSI C.

Changes for POSIX 1003.2 compilance will involve modifications of the
user interface that will start the preference wars all over again.
Great fun coming up.

***

RT-AIX has become more BSD-like in the last few releases.  You might
try out a 2.2.1 machine before you make any more broad comparisons.

>I consider BSD feel to be long file names, symlinks (Steve Dyer mentioned
>these), job control (^Z suspend character, and background/foreground
>operations in C shell), BSD behaviour of tools (ps displaying %memory, %cpu
>and virtual space usage for a process, for instance), dbx, ls displaying
>multiple columns by default (without the need for -C flag which will screw
>you when you try to pipe ls output to a filter -- I know, it's a minor,
>insignificant nuisance, but it bugs me!), etc.
>
>ALL of these exist in AIX PS/2 and AIX 370.  Most (if not all) of these are
>absent from RT AIX.  That's all I was saying.

AIX is intended to be sold both to the constituency you have in mind
(mostly universities, if almost all the RTs you've seen run ACIS) and to
non-engineering businesses where System 5 and X/Open compatibility are
required.  A BSD look and feel is not the only priority.

AIX-RT has dbx and symbolic links.  Some utilities support both SysV and
BSD functionality ('echo' honors both '-n' and '\c', though the
manual page doesn't say so; 'df -k' gives BSD-style output).  AIX-RT
symbolic links to directories have restrictions (to prevent tree
traversal loops) that make them work differently from BSD symlinks.

AIX-RT will become more BSD-like in the near future.  It will have
job control, or IBM will not be able to fulfill government contracts
that require FIPS 151-1 conformance.

	Chuck Karish		karish at mindcraft.com
	(415) 323-9000		karish at forel.stanford.edu



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