/sys$common/syshlp/helplib.hlb CC, Run-time functions, setvbuf  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Associates a buffer with an input or output file.

  Syntax:

       #include <stdio.h>

       int setvbuf (FILE *file_ptr, char *buffer, int type,
                    size_t size);