[comp.sys.mac] Macintosh II ... A/UX Job Control

elwell@osu-eddie.UUCP (Clayton Elwell) (03/20/87)

In article <1226@sfsup.UUCP> shap@sfsup.UUCP (J.S.Shapiro) writes:
>In article <2834@jade.BERKELEY.EDU>, defron@tart6.UUCP writes:
>> 
>> Look, job control is not something that is specific to versions of UNIX, but
>> rather which terminal driver you are using.
>> 
>> It is very possible for Sys V shells to have job control.  Ksh is a prime
>> example.  I believe A/UX comes with sh, csh and ksh.
>> -
>>      Daniel Efron
>
>Sorry, Daniel, but this simply isn't true. In addition to the terminal
>driver interface, you need to define an additional signal, on berkeley
>called SIGTSTP. Many programs (e.g. all screen oriented programs) need
>to understand it. Adding the system call correctly means doing kernel
>changes in Sys V.

I can't resist.  Job control is perfectly possible under System V with a
vanilla kernel.  It requires a modified csh which takes a creative view
of how UNIX processes are set up, but it works.  Several people I know run
it as their normal shell.  Anyone who "knows" it can't be done is welcome to
contact me for a demonstration.  Unfortunately, it was done by a Bell Labs
employee and I'm not sure what the legal status of the code is.   I'll see
if I can find out.  You may say "but it's not REALLY job control."  Well,
I can start up any program, hit ^Z, it stops, if can continue it in the
background, etc.  If it walks like a duck, looks like a duck, and sounds
like a duck, it's close enough to a duck for me.

In any case, A/UX has "real" job control, at least according to the docs I
have seen.

-=-


"The greatest warriors are				Clayton Elwell
the ones who fight for peace."			Elwell@Ohio-State.ARPA
		--Holly Near		   ...!cbosgd!osu-eddie!elwell