Scotch Brand 5.1.10 - Manual (Page 48)

exists a SCOTCHFTYPEACTION () Fortran counterpart, in which the separating
underscore character is replaced by an “F”. In most cases, the Fortran routines
have exactly the same parameters as the C functions, save for an added trailing
INTEGER
argument to store the return value yielded by the function when the
return type of the C function is not void.
Since all the data structures used in libScotch are opaque, equivalent dec-
larations for these structures must be provided in Fortran. These structures must
therefore be defined as arrays of DOUBLEPRECISIONs, of sizes given in file scotchf.h,
which must be included whenever necessary.
For routines which read or write data using a FILE * stream in C, the Fortran
counterpart uses an INTEGER parameter which is the numer of the Unix file descrip-
tor corresponding to the logical unit from which to read or write. In most Unix
implementations of Fortran, standard descriptors 0 for standard input (logical unit
5), 1 for standard output (logical unit 6) and 2 for standard error are opened by
default. However, for files which are opened using OPEN statements, an additional
function must be used to obtain the number of the Unix file descriptor from the
number of the logical unit. This function is called PXFFILENO in the normalized
POSIX Fortran API, and files which use it should include the USE IFPOSIX direc-
tive whenever necessary. An alternate, non normalized, function also exists in most
Unix implementations of Fortran, and is called FNUM.
For instance, the SCOTCH graphInit and SCOTCH graphLoad routines, described
in sections 7.5.1 and 7.5.4, respectively, can be called from Fortran by using the
following code.
INCLUDE "scotchf.h"
DOUBLEPRECISION GRAFDAT(SCOTCH_GRAPHDIM)
INTEGER RETVAL
...
CALL SCOTCHFGRAPHINIT (GRAFDAT (1), RETVAL)
IF (RETVAL .NE. 0) THEN
...
OPEN (10, FILE=’brol.grf’)
CALL SCOTCHFGRAPHLOAD (GRAFDAT (1), FNUM (10), 1, 0, RETVAL)
CLOSE (10)
IF (RETVAL .NE. 0) THEN
...
Although the “scotchf.h” and “ptscotchf.h” files may look very similar on
your system, never mistake them, and always use the “scotchf.h” file as the in-
clude file for compiling a program which uses only the sequential routines of the
libScotch
library.
7.1.3 Compiling and linking
The compilation of C or Fortran routines which use routines of the libScotch
library requires that either scotch.h or scotchf.h be included, respectively.
The routines of the libScotch library are grouped in a library file called
libscotch.a . Default error routines that print an error message and exit are pro-
vided in library file libscotcherr.a.
Therefore, the linking of applications that make use of the libScotch li-
brary with standard error handling is carried out by using the following options:
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