libio/ftello64.c

   1 /* Copyright (C) 1993, 1995-2001, 2002, 2003, 2004
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.
  18
  19    As a special exception, if you link the code in this file with
  20    files compiled with a GNU compiler to produce an executable,
  21    that does not cause the resulting executable to be covered by
  22    the GNU Lesser General Public License.  This exception does not
  23    however invalidate any other reasons why the executable file
  24    might be covered by the GNU Lesser General Public License.
  25    This exception applies to code released by its copyright holders
  26    in files containing the exception.  */
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <libioP.h>
  31 #include <errno.h>
  32
  33
  34 off64_t
  35 ftello64 (fp)
  36      _IO_FILE *fp;
  37 {
  38 #ifdef _G_LSEEK64
  39   _IO_off64_t pos;
  40   CHECK_FILE (fp, -1L);
  41   _IO_acquire_lock (fp);
  42   pos = _IO_seekoff_unlocked (fp, 0, _IO_seek_cur, 0);
  43   if (_IO_in_backup (fp) && pos != _IO_pos_BAD)
  44     {
  45       if (fp->_mode <= 0)
  46         pos -= fp->_IO_save_end - fp->_IO_save_base;
  47     }
  48   _IO_release_lock (fp);
  49   if (pos == _IO_pos_BAD)
  50     {
  51 #ifdef EIO
  52       if (errno == 0)
  53         __set_errno (EIO);
  54 #endif
  55       return -1L;
  56     }
  57   return pos;
  58 #else
  59   __set_errno (ENOSYS);
  60   return -1;
  61 #endif
  62 }