| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copyright (C) 1993-2016 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 Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the 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 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <http://www.gnu.org/licenses/>. |
| 17 | |
| 18 | As a special exception, if you link the code in this file with |
| 19 | files compiled with a GNU compiler to produce an executable, |
| 20 | that does not cause the resulting executable to be covered by |
| 21 | the GNU Lesser General Public License. This exception does not |
| 22 | however invalidate any other reasons why the executable file |
| 23 | might be covered by the GNU Lesser General Public License. |
| 24 | This exception applies to code released by its copyright holders |
| 25 | in files containing the exception. */ |
| 26 | |
| 27 | #include "libioP.h" |
| 28 | #include <stdlib.h> |
| 29 | #include <errno.h> |
| 30 | /* ANSI explicily requires setting errno to a positive value on failure. */ |
| 31 | |
| 32 | long int |
| 33 | _IO_ftell (_IO_FILE *fp) |
| 34 | { |
| 35 | _IO_off64_t pos; |
| 36 | CHECK_FILE (fp, -1L); |
| 37 | _IO_acquire_lock (fp); |
| 38 | pos = _IO_seekoff_unlocked (fp, 0, _IO_seek_cur, 0); |
| 39 | if (_IO_in_backup (fp) && pos != _IO_pos_BAD) |
| 40 | { |
| 41 | if (_IO_vtable_offset (fp) != 0 || fp->_mode <= 0) |
| 42 | pos -= fp->_IO_save_end - fp->_IO_save_base; |
| 43 | } |
| 44 | _IO_release_lock (fp); |
| 45 | if (pos == _IO_pos_BAD) |
| 46 | { |
| 47 | #ifdef EIO |
| 48 | if (errno == 0) |
| 49 | __set_errno (EIO); |
| 50 | #endif |
| 51 | return -1L; |
| 52 | } |
| 53 | if ((_IO_off64_t) (long int) pos != pos) |
| 54 | { |
| 55 | #ifdef EOVERFLOW |
| 56 | __set_errno (EOVERFLOW); |
| 57 | #endif |
| 58 | return -1L; |
| 59 | } |
| 60 | return pos; |
| 61 | } |
| 62 | libc_hidden_def (_IO_ftell) |
| 63 | |
| 64 | #ifdef weak_alias |
| 65 | weak_alias (_IO_ftell, ftell) |
| 66 | #endif |