CW2, Callable wgrib2


Wgrib2 can be called by a C and fortrans programs by linking in the appropriate libraries/subroutines.

C: call wgrib2(int argc, char **argv);
     same format as main program parameters

F: call wgrib2(n, strings)
   integer n
   character (len=*) strings(n)
   string(1)..string(n) are arguments to wgrib2

Options that are specific to callable wgrib2 are

 -close_persistent_file init X      close persistent file, X=filename CW2
 -persistent_file init X      makes file persistent if already opened, X=filename CW2
 -rewind_file     init X      rewinds file if already opened, X=filename, CW2

 -last2mem        inv> X Y    write last inv item to memory X=address of data Y=max # characters
 -import_mem      misc X Y    read memory for data, X=address of data, Y=number of grid points
 -grid2mem        out  X Y Z  write grid to memory X=address of data, Y=address of #points Z=max # points

Fortran comments:
  I am quite satisfied with the non-CW2 fortran api for writing grib2.
I expect an api for reading grib2 using CW2 in the future.



--------------- sample C program ----------
#include <stdio.h>

int wgrib2(int argc, char **argv);

int main() {
        int w_argc, ierr;
        char *w_argv[10];

        w_argc=2;
        w_argv[0] = "my program";
        w_argv[1] = "-config";

        ierr=wgrib2(w_argc, w_argv);
	return ierr;
}
--------------- sample Fortran program ----------
        character*100 lines(10)

        lines(1) = 'ds.td.bin'
        lines(2) = '-s'
        call wgrib2(2,lines)
        stop
        end