VMS Help CC, Run-time functions, fgetname  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Returns the file specification associated with a file pointer.

  Syntax:

       #include <stdio.h>

       char *fgetname(FILE *file_pointer, char *buffer,...);

  where the ...  is an optional additional argument that can be
  either 1 or 0.  If you specify 1, fgetname returns the file
  specification in OpenVMS format.  If you specify 0, fgetname
  returns the file specification in UNIX style format.

  If this argument is omitted, fgetname returns the file name
  according to your current command language interpreter.