glibc/sysdeps/unix/telldir.c

/* Copyright (C) 1991, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <ansidecl.h>
#include <errno.h>
#include <stddef.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/types.h>
#include "dirstream.h"

/* Return the current position of DIRP.  */
off_t
DEFUN(telldir, (dirp), DIR *dirp)
{
  register off_t pos;

  if (dirp == NULL)
    {
      errno = EINVAL;
      return (off_t) -1;
    }

  pos = __lseek(dirp->__fd, (off_t) 0, SEEK_CUR);
  if (pos == (off_t) -1)
    return (off_t) -1;
  return pos + (dirp->__size - dirp->__offset);
}