1: /* Copyright (C) 1993, 1995-2000, 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, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.
   19: 
   20:    As a special exception, if you link the code in this file with
   21:    files compiled with a GNU compiler to produce an executable,
   22:    that does not cause the resulting executable to be covered by
   23:    the GNU Lesser General Public License.  This exception does not
   24:    however invalidate any other reasons why the executable file
   25:    might be covered by the GNU Lesser General Public License.
   26:    This exception applies to code released by its copyright holders
   27:    in files containing the exception.  */
   28: 
   29: #include "libioP.h"
   30: #include <stdlib.h>
   31: #include <errno.h>
   32: /* ANSI explicily requires setting errno to a positive value on failure. */
   33: 
   34: long int
   35: _IO_ftell (fp)
   36:      _IO_FILE *fp;
   37: {
   38:   _IO_off64_t pos;
   39:   CHECK_FILE (fp, -1L);
   40:   _IO_acquire_lock (fp);
   41:   pos = _IO_seekoff_unlocked (fp, 0, _IO_seek_cur, 0);
   42:   if (_IO_in_backup (fp) && pos != _IO_pos_BAD)
   43:     {
   44:       if (_IO_vtable_offset (fp) != 0 || fp->_mode <= 0)
   45:         pos -= fp->_IO_save_end - fp->_IO_save_base;
   46:     }
   47:   _IO_release_lock (fp);
   48:   if (pos == _IO_pos_BAD)
   49:     {
   50: #ifdef EIO
   51:       if (errno == 0)
   52:         __set_errno (EIO);
   53: #endif
   54:       return -1L;
   55:     }
   56:   if ((_IO_off64_t) (long int) pos != pos)
   57:     {
   58: #ifdef EOVERFLOW
   59:       __set_errno (EOVERFLOW);
   60: #endif
   61:       return -1L;
   62:     }
   63:   return pos;
   64: }
   65: INTDEF(_IO_ftell)
   66: 
   67: #ifdef weak_alias
   68: weak_alias (_IO_ftell, ftell)
   69: #endif