Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!noao!arizona!naucse!jdc
From: jdc@naucse.UUCP (John Campbell)
Newsgroups: comp.unix.wizards
Subject: Re:  Ultrix/32 & VMS
Message-ID: <1184@naucse.UUCP>
Date: 2 Mar 89 18:49:11 GMT
References: <18496@adm.BRL.MIL>
Organization: Northern Arizona University, Flagstaff, AZ
Lines: 42

From article <18496@adm.BRL.MIL>, by drs@bnlux0.bnl.gov (David R. Stampf):
With regard to porting unix 'C' to VMS:
> 
> 	Actually file formats are the least of your problems (although it is
> a BIG problem!).  If you are porting code from unix to vms beware of
> 
> 	1) signals - there simply aren't that many on vms
> 	2) ioctl -   simply isn't there
> 	3) fork -    works differently
> 	4) select -  ain't there either.
> 	5) #includes - the directory names don't work without some work on
> 			your part to define some alises.
You forgot link() and unlink().
> 
> 	The problem is that the system level stuff in unix is really easy
> to get at with one or two lines of code while the vms stuff is a bear to
> get at from C.  For example, with 3 ioctl call in unix you can learn all

...  and lots of reasonable, but scary compatiblity concerns.

> 	Actually in my experience, if you told me that you were concerned
> with moveing Fortran from one machine to another, I would feel that your
> chances were much better.  I just don't feel that C code (not the language,
> but the programs)  is all that portable.
> 

Well, how about gawk, bison, flex, sc, diff, patch, and a whole bunch more
``small'' programs that I've taken over to VMS.  Everything you've said is
true in theory, but my experience has been that a lot of code is relatively
portable and the problems encountered are familiar and easy to solve.  VMS
can be a pain, but I disagree that FORTRAN is easier to port than 'C' 
(especially VMS FORTRAN from some place like LLL's headed toward unix...).

Don't discourage people from trying these ports!  There is a ton of very
nice unix code that can be ported and used on the more deficient VMS
system (for those of us who will continue to earn a living on these
dying machines the next few years).

-- 
	John Campbell               ...!arizona!naucse!jdc
                                    CAMPBELL@NAUVAX.bitnet
	unix?  Sure send me a dozen, all different colors.