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From: lars@myab.UUCP (lars)
Newsgroups: net.unix-wizards
Subject: Re: UNIX Futures
Message-ID: <137@myab.UUCP>
Date: Sat, 15-Mar-86 23:47:40 EST
Article-I.D.: myab.137
Posted: Sat Mar 15 23:47:40 1986
Date-Received: Wed, 19-Mar-86 05:30:18 EST
References: <67@cstvax.UUCP> <2864@amdahl.UUCP>
Reply-To: lars@myab.UUCP (lars)
Distribution: net
Organization: Myab Gothenburg, Sweden
Lines: 39


>In article <67@cstvax.UUCP>, scott@cstvax.UUCP (Scott Larnach) writes:
>> 
>> The one and only real thing which bugs me about system V is the
>> total lack of job control.
>> 
>> Come on, AT&T, give me job control and I'll be a believer.
>
>Uhh, excuse me, but what about shell layers ( shl ) ? It does not
>give you job control, per se, but it does allow you to break out
>of a foreground process, to 'do something else'.

We have ported 'csh' to SVR2 using shell layers. Result:

A program started with '&' runs in background. If it want to
do tty input, it will hang until put in foreground.

A background program can be put in foreground with the 'fg' command.

A forground program can be stopped with the '^Z' key. Csh will then
type 'blocked' and not 'stopped', because only tty io is blocked and the
program continues.

Typing 'bg' to a 'blocked' will enable output to tty for the blocked
program.

A maximum of 7 programs can be executed simultaneously.

A program cannot catch '^Z'. This implies that 'vi' doesn't redraw its
screen.

Csh reads 'type ahead' characters back from a blocked sxt and inserts them
into the current input line. Otherwise, type ahead wouldn't have worked.

Despite these limits, it is much better than 'shl' (which creates one
new 'sh' for each "job").
-- 
    ______________________________________________________
	Lars Pensjo
	{decvax,philabs}!mcvax!enea!chalmers!myab!lars