[TUHS] A few comments on porting the Bourne shell

[Chet Ramey]

On 12/31/22 2:24 PM, Clem Cole wrote:

>     I seem to remember that someone got wedged into System V
>     that was awful and unusable.
> 
> IIRC it was in SVR2 that a version of a job control system added some of 
> the semantics of Kulp's scheme to the kernel, but not all as you point out 
> and it was pretty disappointing if you had grown up on BSD systems.  Later 
> POSIX would pick up the Kulp/BSD Job Control definition and by SVR3/SVR4 
> AT&T fleshed out all all of the semantics.

There is a pretty good discussion of 4.2 BSD-style job control and ways to
make it fit with System V semantics (mostly controlling terminals and, of
course, process groups) at

https://web.physics.ucsb.edu/~pcs/apps/bash/job.control.ps

This is probably the best description of BSD-style job control, and it is
the inspiration for much of the POSIX job control design (e.g., their
invention of "sessions" as the replacement for System V style process
groups).

Chet
-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
		 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet at case.edu    http://tiswww.cwru.edu/~chet/