Pointers (Fortran Programming Guide)

Fortran Programming Guide

Pointers

A FORTRAN 77 pointer can be passed to a C routine as a pointer to a pointer because the Fortran routine passes arguments by reference.

Table 11-11 Passing a FORTRAN 77 POINTER


Fortran calls C	C calls Fortran
`REAL X` `POINTER (P2X, X)` `EXTERNAL PASS` `P2X = MALLOC(4)` `X = 0.` `CALL PASS(X)` `...` `------------------------------` `void pass_(x)` `int x;` `{` `x = 100.1;` `}`	`extern void fpass_;` `...` `float x;` `float *p2x;` `fpass_(p2x) ;` `...` `------------------------------` `SUBROUTINE FPASS (P2X)` `REAL X` `POINTER (P2X, X)` `X = 0.` `...`

C pointers are compatible with Fortran 90 (release 2.0) scalar pointers, but not array pointers.