Path: utzoo!attcan!uunet!ncc!alberta!anthony
From: anthony@alberta.UUCP (Anthony Mutiso)
Newsgroups: comp.unix.questions
Subject: Re: linking "C" and FORTRAN functions together
Message-ID: <237@snipe-lake.UUCP>
Date: 5 Mar 89 00:38:10 GMT
References: <1599@aucs.UUCP>
Distribution: na
Organization: U. of Alberta, Edmonton, AB
Lines: 43

In article <1599@aucs.UUCP>, 850181p@aucs.UUCP (STEVEN E. PARKER) writes:
> I am trying to find out how to link a fortran library
> subroutine "SVD" into a "C" program.
> I know that you have to compile the souce
> to  .o files but what do you do next???

Have a look at your Unix programmers manual "Fortran and Friends".  It
does say something about how to solve your problem, if memory serves.
In general here is what you need to understand:-

	(1) Fortran data types are passed to functions by default in
	    a manner that is different to the default C manner (especially
	    text string, which have to include a byte length).

	(2) The f77 compiler will compile fortran code to names with
	    two underscores.  e.g.. the fortran procedure "map" will
	    compile to the identifier "__map", while the C name "map"
	    will compile to the identifier "_map". So to access the
	    fortran subroutine in a C file the name "_map" will have
	    to be used to reach the fortran name "map".  Watch out of
	    course for subroutine naming conventions, ie. calling a C
	    function from the fortran program.

I hope this is sufficient to get you going.

Anthony.

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Anthony Mutiso							Email

Department of Computing Science.			anthony@UAlberta.AB.CA
University of Alberta				or	anthony@alberta.UUCP
Edmonton, Alberta
CANADA
Tel: (office) 403-432-2821

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		...... angle and ministers of grace defend us all......
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