sysdeps/unix/telldir.c

   1 /* Copyright (C) 1991 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <stddef.h>
  22 #include <dirent.h>
  23 #include <unistd.h>
  24 #include <sys/types.h>
  25
  26 /* Return the current position of DIRP.  */
  27 off_t
  28 DEFUN(telldir, (dirp), DIR *dirp)
  29 {
  30   register off_t pos;
  31
  32   if (dirp == NULL)
  33     {
  34       errno = EINVAL;
  35       return (off_t) -1;
  36     }
  37
  38   pos = __lseek(dirp->__fd, (off_t) 0, SEEK_CUR);
  39   if (pos == (off_t) -1)
  40     return (off_t) -1;
  41   return pos + (dirp->__size - dirp->__offset);
  42 }