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glibc  2.9
ftello64.c
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00001 /* Copyright (C) 1993, 1995-2001, 2002, 2003, 2004
00002    Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.
00019 
00020    As a special exception, if you link the code in this file with
00021    files compiled with a GNU compiler to produce an executable,
00022    that does not cause the resulting executable to be covered by
00023    the GNU Lesser General Public License.  This exception does not
00024    however invalidate any other reasons why the executable file
00025    might be covered by the GNU Lesser General Public License.
00026    This exception applies to code released by its copyright holders
00027    in files containing the exception.  */
00028 
00029 #include <stdio.h>
00030 #include <stdlib.h>
00031 #include <libioP.h>
00032 #include <errno.h>
00033 
00034 
00035 off64_t
00036 ftello64 (fp)
00037      _IO_FILE *fp;
00038 {
00039 #ifdef _G_LSEEK64
00040   _IO_off64_t pos;
00041   CHECK_FILE (fp, -1L);
00042   _IO_acquire_lock (fp);
00043   pos = _IO_seekoff_unlocked (fp, 0, _IO_seek_cur, 0);
00044   if (_IO_in_backup (fp) && pos != _IO_pos_BAD)
00045     {
00046       if (fp->_mode <= 0)
00047        pos -= fp->_IO_save_end - fp->_IO_save_base;
00048     }
00049   _IO_release_lock (fp);
00050   if (pos == _IO_pos_BAD)
00051     {
00052 #ifdef EIO
00053       if (errno == 0)
00054        __set_errno (EIO);
00055 #endif
00056       return -1L;
00057     }
00058   return pos;
00059 #else
00060   __set_errno (ENOSYS);
00061   return -1;
00062 #endif
00063 }