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From: "Rodney W. Grimes" <rgrimes@gndrsh.aac.dev.com>
Message-Id: <199504220526.WAA00958@gndrsh.aac.dev.com>
Subject: Re: Any objection to adding a .undef(VARNAME) to make?
To: peter@bonkers.taronga.com (Peter da Silva)
Date: Fri, 21 Apr 1995 22:26:46 -0700 (PDT)
Cc: nate@trout.sri.MT.net, jkh@freefall.cdrom.com, hackers@freefall.cdrom.com
In-Reply-To: <199504220339.WAA06361@bonkers.taronga.com> from "Peter da Silva" at Apr 21, 95 10:39:20 pm
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> 
> > FOO= 1
> 
> > FOO= undefined
> 
> How about just:
> 
> 	FOO=
> 
> make an empty definition undefined. Undefineds are treated as empty in make
> anyway. It would also match the way .SUFFIXES: works.

That is in ``make'', read the psd:12 manual for the difference between
undefined and variables that are empty, it is different in pmake.  I have
not verified that our make truely follows the pmake manual in this regard,
but I do seem to recall having some trouble in this area.


-- 
Rod Grimes                                      rgrimes@gndrsh.aac.dev.com
Accurate Automation Company                   Custom computers for FreeBSD