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From: rich@rexago1.UUCP (K. Richard Magill)
Newsgroups: net.unix-wizards,net.unix
Subject: Re: UNIX question
Message-ID: <127@rexago1.UUCP>
Date: Mon, 16-Dec-85 10:59:47 EST
Article-I.D.: rexago1.127
Posted: Mon Dec 16 10:59:47 1985
Date-Received: Wed, 18-Dec-85 04:32:01 EST
References: <156@uw-june> <974@ccice5.UUCP> <2548@umcp-cs.UUCP> <14767@onfcanim.UUCP>
Reply-To: rich@rexago1.UUCP (K. Richard Magill)
Organization: Roadway Express Inc., Akron, OH
Lines: 42
Xref: watmath net.unix-wizards:16138 net.unix:6652
Summary: 

In article <14767@onfcanim.UUCP> dave@onfcanim.UUCP (Dave Martindale) writes:
>In article <2548@umcp-cs.UUCP> chris@umcp-cs.UUCP (Chris Torek) writes:
>>If there is any way to reliably handle
>>process exit and `job control' style processing in System III and
>>System V, I am not aware of it---
>It seems that SIGCLD is generated
>by the presence of a zombie child, not the event of a child terminating.

In the spirit of information sharing...

With respect to a 3b2/300 running SV.2.2...

I guess I can't/shouldn't copy the manual but SIGCLD is generated by the
death of a child and reset when  caught.  ...  behaves as other  signals
with the  exception  that  successive SIGCLD's  are  queued  instead  of
successively interrupting the catching function.

A rudimentary job control has been accomplished on SV.2.2.  It  consists
of a parent process that calls  subprocesses which are $SHELL.  All  you
can do from the  parent, shl, is create,  delete, block, unblock,  list,
etc.  ie,  job control only.   not really  a shell.   Typing your  SWTCH
character from a child gets you back to shl, with the child  effectively
bg'd, from which  you may  create a  new subshell.   Of  course you  are
limited to eight subprocesses.  All of this is accomplished using pseudo
terminals, (sxt's), a new  control character defined in  termio.c_cc[7],
SWTCH, a new control  mode, in (termio.c_cflag  & 0x10000), LOBLK  which
blocks output of the current layer.

I should add that  shl cannot be  your login shell  and doesn't work  if
exec'd from you login shell.  I do use it.  It's not csh but its  better
than sh alone.

Ksh is puported to do csh style job control on 3b2 but I have yet to see
it work.  The copies  I have seen tend  to lock up terminals  frequently
when you try.

AGAIN!   This is  3b2/300 SV.2.2.   I  know that  the pc7300  SV  pc7300
version 3 does NOT  have these features and  I can't speak for  anything
else.

K. Richard Magill
Have I violated copyright?  Have I said something stupid?