Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ulowell!hawk.ulowell.edu!arosen
From: arosen@hawk.ulowell.edu (MFHorn)
Newsgroups: comp.unix.wizards
Subject: Re: generating code to run multiple targets/configurations from single
Message-ID: <12741@swan.ulowell.edu>
Date: 11 Apr 89 11:54:53 GMT
References: <3129@stpstn.UUCP> <18927@adm.BRL.MIL> <10445@bloom-beacon.MIT.EDU>
Sender: news@swan.ulowell.edu
Reply-To: arosen@hawk.ulowell.edu
Organization: University of Lowell, CS Dept
Lines: 38

> >>I need (for a long time) a better way to produce multiple configurations on
> >>multiple targets from a single set of sources.
> 
> I like the way X 11.3 does it -- you have one tree of sources, and for each
> make you create a tree of links into it.

Tcsh added two environment variables, HOST and HOSTTYPE.  HOST is your
hostname, HOSTTYPE is compile-time configurable.  I like the idea, but
to be really useful, it has to become part of configuration files and
part of the filesystem.

I should be able to put into a makefile a line like

prog: prog.c prog.h
	cc prog.c -o $HOSTTYPE/prog

All programs that use some sort of configuration file (inetd, syslog,
sendmail) would need to recognize $ENVIRONMENT to be really useful.


lrwx------  1 arosen       9 Jan  1 00:00 bin -> bin/$HOSTTYPE
[for this, you could "set path = ( ~/bin/$HOSTTYPE $path )"]
lrwx------  1 arosen      19 Jan  1 00:00 .Xdefaults -> $DISPLAY/.Xdefaults
lrwx------  1 arosen      14 Jan  1 00:00 .history -> $HOST/.history

All that's needed is an efficient way for the kernel to get at a process'
environment variables.

Yeah, I know ATT has also suggested environment variables be incorporated
into path names, but I came up with the idea on my own before I heard
about it.  Honest.  I just would've had a little more trouble getting the
idea in print.

--
Andy Rosen           | arosen@hawk.ulowell.edu | "I got this guitar and I
ULowell, Box #3031   | ulowell!arosen          |  learned how to make it
Lowell, Ma 01854     |                         |  talk" -Thunder Road
		RD in '88 - The way it should've been