Current:

  GDBM_FILE gdbm_open (const char *file,
    	               int block_size,
	               int flags,
  	               int mode,
     	               void (*fatal_func) (const char *))

Planned:
  GDBM_FILE gdbm_open_X (const char *file, int flags);
  GDBM_FILE gdbm_creat_X (const char *file, int flags, int block_size);

  GDBM_FILE gdbm_open_Y (const char *file, int flags, ...);
  enum {
    GDBM_OPEN_FD,
    GDBM_OPEN_BLOCK_SIZE,
    GDBM_OPEN_CREAT_MODE,
    GDBM_OPEN_FATAL_FUNC,
  }