From mboxrd@z Thu Jan  1 00:00:00 1970
From: rmswierczek@gmail.com (Robert Swierczek)
Date: Tue, 3 Jan 2017 16:53:02 -0500
Subject: [TUHS] When was #if introduced in C? (was: Re: Mac OS X is Unix)
In-Reply-To: <20170103213331.GN31772@yeono.kjorling.se>
References: <201701032019.v03KJ8oq028944@tahoe.cs.Dartmouth.EDU>
 <CANV78LQLKO03sCPVUe-EbiJonL-kgPQn1x+pm=FN3WWRZ7xLvg@mail.gmail.com>
 <20170103213331.GN31772@yeono.kjorling.se>
Message-ID: <CAAFR5pb8d1msb+XdWPPKvAsO=eQsPgiAY8Q3cVRxoQtj_PtWkg@mail.gmail.com>

> Which makes me curious... Does anyone here happen to know when #if was introduced in C?

>From what I can gather from studying the TUHS archives, the earliest
cpp that supports #if is in PWB:
http://minnie.tuhs.org/cgi-bin/utree.pl?file=PWB1/sys/c/c/cpp.c

Before that, the pre-processor resides within the cc.c command and #if
is not supported:
http://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/source/s1/cc.c