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From: David Luyer <david_luyer@pacific.net.au>
To: Tim Goodwin <tjg@star.le.ac.uk>
Cc: rc@hawkwind.utcs.toronto.edu
Subject: Re: building rc on QNX4 
Date: Mon, 8 May 2000 07:50:18 -0400
Message-ID: <200005081150.VAA20547@typhaon.pacific.net.au> (raw)
In-Reply-To: <tjg@star.le.ac.uk>


Tim Goodwin wrote:
> >                                                                  another
> > one is whether it will ever make it possible not to export everything to
> > the environment by default.
> 
> I brought this up a few months ago, and the consensus seemed to be that
> the current scheme works well enough in practice.  Have you encountered
> a problem?

I encountered a problem with this years ago but just started using
"su -" when I was trying to get programs to run that it broke.

Basically some OS's (Digital Unix for one I think) have C libraries which
choke horribly if the size of the command line + environment array is greater 
than a certain value, and if you have a number of complex functions in your 
shell this value (64k?) can be a pain.

Although it is really useful to have the shell functions inherited by a shell 
which was spawned from some unrelated program running under the initial shell,
maybe we need some way to prevent this in specific cases?

Maybe some syntax along the lines of:

(+ HOME PATH path USER LOGNAME "fn "*) /usr/sbin/cron &

to pass HOME, PATH, path, USER, LOGNAME and fn_* only

(- "fn "*) /usr/sbin/cron &

to pass everything but fn_*

But then - as with most things this could be done in a function

eg: run sh with HOME USER LOGNAME
    run sh without "fn "*

which could be implemented relatively easily if there was an option to whatis 
to just list variables instead of show what they are.

(eg: "whatis -fq" - list functions, "whatis -vq" - list variables)

Anyway - basically - I think it might be more useful to extend whatis such
that it can be used to implement easily a facility to run a command without 
any environment variables, rather than to actually implement that facility 
internally.

David.
-- 
----------------------------------------------
David Luyer
Senior Network Engineer
Pacific Internet (Aust) Pty Ltd
Phone:  +61 3 9674 7525
Fax:    +61 3 9699 8693
Mobile: +61 4 1064 2258, +61 4 1114 2258
http://www.pacific.net.au        NASDAQ: PCNTF
<< fast 'n easy >>
----------------------------------------------




  parent reply index

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-09-17 15:56 are there any patches which add ~ expansion to rc Joseph Skinner
1997-09-17 21:56 ` Scott Schwartz
1997-09-17 22:08 ` Mark K. Gardner
1997-09-18 23:26 Chris Siebenmann
     [not found] ` <cks@hawkwind.utcs.toronto.edu>
1992-06-04 10:05   ` $pid malte
1992-11-04 12:45   ` set subtract malte
1992-11-06 12:03   ` rc and signal handlers malte
1997-09-19 17:21   ` are there any patches which add ~ expansion to rc Jeremy Fitzhardinge
2001-10-24  3:25   ` Beta release rc-1.6b3 available Chris Siebenmann
2001-10-24  3:41     ` Scott Schwartz
     [not found] <sroberts@uniserve.com>
2000-04-26 15:02 ` building rc on QNX4 Sam Roberts
2000-04-27 16:56   ` Scott Schwartz
2000-04-27 20:41     ` Sam Roberts
2000-04-28  7:28       ` vrl (was: Re: building rc on QNX4) Gert-Jan Vons
2000-04-28 18:38         ` Sam Roberts
2000-05-02  8:16           ` Gert-Jan Vons
2000-04-28 19:03         ` rc not session leader? Sam Roberts
2000-04-27 17:39   ` building rc on QNX4 Carlo Strozzi
2000-05-02 14:41     ` Tim Goodwin
2000-05-04 15:18       ` Carlo Strozzi
2000-05-08  8:29         ` Tim Goodwin
2000-05-08  8:58           ` Chris Siebenmann
2000-05-08  9:15             ` Tim Goodwin
2000-05-08 23:25               ` Stephen Tell
2000-05-10  0:37                 ` builtins Scott Schwartz
2000-05-12  7:22                   ` builtins Carlo Strozzi
     [not found]           ` <tjg@star.le.ac.uk>
2000-05-08 11:50             ` David Luyer [this message]
2002-04-04 10:04             ` rc 1.6 $version Tim Goodwin
2002-04-04 21:42               ` Scott Schwartz
2000-05-08 13:28           ` building rc on QNX4 Carlo Strozzi
2000-05-04  8:45 Byron Rakitzis
2000-05-06 10:28 ` Carlo Strozzi
2000-05-07 17:46   ` Paul Haahr
2000-05-08  8:01     ` Carlo Strozzi
2000-05-06 16:35 ` Jeremy Fitzhardinge
2000-05-04 13:46 Sam Roberts
2000-05-06 21:47 Byron Rakitzis
2000-05-08 10:19 Bengt Kleberg
2000-05-08 15:15 Smarasderagd
2000-05-09  8:22 ` Carlo Strozzi
2000-05-08 15:23 Sam Roberts
2000-05-09  8:25 ` Carlo Strozzi
2000-05-09  4:34 Smarasderagd
2000-05-11 12:26 ` Gert-Jan Vons
2001-10-15 13:56 Beta release rc-1.6b3 available Tim Goodwin
2001-10-17 14:13 ` Buggs
2001-10-17 14:34   ` Tim Goodwin
2001-10-17 21:13     ` Buggs
2001-10-23  7:55 ` Carlo Strozzi
2001-10-23 12:44   ` Tim Goodwin
2001-10-23 15:47   ` Markus Friedl
2001-10-23 21:09     ` Carlo Strozzi
     [not found] <sroberts@certicom.com>
2001-10-23 15:55 ` Sam Roberts
2001-10-23 21:14   ` Scott Schwartz
2001-10-23 21:32 Carlo Strozzi
2001-10-24  3:34 ` Chris Siebenmann
2001-10-24  8:04   ` Carlo Strozzi
2002-03-14 22:37 rc 1.6 $version erik quanstrom
2002-03-27 13:27 ` Tim Goodwin
2002-03-27 21:12   ` Carlo Strozzi
2002-03-30 18:43     ` Paul Haahr
2002-03-31 15:13       ` Carlo Strozzi
2002-04-03 14:31       ` Tim Goodwin
2002-04-03 15:06         ` Paul Haahr

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