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From: Rminnich@UDEL.EDU
Newsgroups: comp.unix.wizards
Subject: Concatenation with cpp.
Message-ID: <7257@brl-adm.ARPA>
Date: Wed, 6-May-87 09:57:03 EDT
Article-I.D.: brl-adm.7257
Posted: Wed May  6 09:57:03 1987
Date-Received: Fri, 8-May-87 04:09:55 EDT
Sender: news@brl-adm.ARPA
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   If you want to concatenate and you do not want to be 
portable, then 
#define cat(x,y)	x/* */y
works on many BSD systems. It will not work on SCO Xenix at all
and it sounds like it fails on SYS V too. It fails on SCO Xenix 
because they defined their own, improved cpp (called p0)
which of course does things differently. I just got bit 
by this in a big way on a piece of imported software. 
Our solution was adding the extra process. 

   It does not seem a good idea to use comments as an infix
concatenate operator, which is really what the above is. If
you really need the concatenate, and you do not want an 
extra process, then get GNU cpp. It supports concatenate
pretty nicely. It also uses alloca, which i understand 
is a very portable function :-) (which is why we do not 
use it on Xenix). If you want a copy 
please let me know.
ron (rminnich@udel.edu)