Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!utcsri!flaps From: flaps@utcsri.UUCP Newsgroups: comp.lang.c Subject: Where is unix pre#defined? -- summary of responses. Message-ID: <4756@utcsri.UUCP> Date: Sat, 9-May-87 16:15:57 EDT Article-I.D.: utcsri.4756 Posted: Sat May 9 16:15:57 1987 Date-Received: Sat, 9-May-87 18:16:57 EDT Reply-To: flaps@utcsri.UUCP (Alan J Rosenthal) Distribution: world Organization: University of Toronto Lines: 54 In article <4572@utcsri.UUCP> I (Alan J Rosenthal ) wrote: >Where is the pre-processor macro 'unix' pre#defined? >Is this a Berkeleyism or can I use this to find out if I really am under >unix or not? Or alternatively, what other words are there? Does System V >#define unix? Does version 7? Responses were numerous and informative. The basic answer is that all unix compilers should #define unix. Johan Vromans wrote: >*ALL* unix systems I have met had unix defined, except for >Xenix systems. Most of them had additional defines to discriminate. > >"Normal" unix systems include Perkin-Elmer, National Semiconductor, >NCR, Sperry, Harris, VAX/BSD4.[123], AT&T, SystemV/AT, Hewlett-Packard, >Zilog, Gould, Burroughs, VAX/Nuxi, Sun. > >Xenix systems are Xenix 2, Xenix 3 and Xenix 5. guy@sun.uucp (Guy Harris) wrote: >"unix" is predefined by UNIX C implementations using the Reiser >preprocessor, as long as somebody working on the implementation >didn't screw up and remove it. This preprocessor first appeared in >V7; it is the basis of the 4BSD and S3/S5 C preprocessors. I presume >at least some UNIX C implementations not using the Reiser >preprocessor also predefine "unix"; one hopes there are no UNIX C >implementations that do not predefine "unix", although it is not >inconceivable that somebody could be stupid enough to produce such an >implementation. After some correspondence he also added: >Well, it looks like the S5R3 preprocessor will define "DMERT", rather >than "unix", on the DMERT OS. ("cpp" itself says "#if unix || DMERT" >in several places.) Then again, while DMERT is like UNIX, it's not >clear whether you can say it is UNIX. I also got helpful responses from iaoobel!wagner@unido.uucp (Juergen Wagner), billj@zaphod.uucp (Bill Jones), and pegasus!hansen@ihnp4.uucp (Tony Hansen). -- Alan J Rosenthal flaps@csri.toronto.edu, {seismo!utai or utzoo}!utcsri!flaps, flaps@toronto on csnet, flaps at utorgpu on bitnet. "Probably the best operating system in the world is the [operating system] made for the PDP-11 by Bell Laboratories." - Ted Nelson, October 1977