1 /* An ftello() function that works around platform bugs.
2 Copyright (C) 2007, 2009-2016 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program 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
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
25 #include "stdio-impl.h"
34 #if _GL_WINDOWS_64_BIT_OFF_T
36 # if HAVE__FTELLI64 /* msvc, mingw64 */
37 # define ftello _ftelli64
39 # define ftello ftello64
44 /* mingw gives bogus answers rather than failure on non-seekable files. */
45 if (lseek (fileno (fp), 0, SEEK_CUR) == -1)
49 #if FTELLO_BROKEN_AFTER_SWITCHING_FROM_READ_TO_WRITE /* Solaris */
50 /* The Solaris stdio leaves the _IOREAD flag set after reading from a file
51 reaches EOF and the program then starts writing to the file. ftello
52 gets confused by this. */
53 if (fp_->_flag & _IOWRT)
57 /* Call ftello nevertheless, for the side effects that it does on fp. */
60 /* Compute the file position ourselves. */
61 pos = lseek (fileno (fp), (off_t) 0, SEEK_CUR);
64 if ((fp_->_flag & _IONBF) == 0 && fp_->_base != NULL)
65 pos += fp_->_ptr - fp_->_base;
71 #if defined __SL64 && defined __SCLE /* Cygwin */
72 if ((fp->_flags & __SL64) == 0)
74 /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
75 mode; but has an ftello that requires 64-bit mode. */
76 FILE *tmp = fopen ("/dev/null", "r");
80 fp->_seek64 = tmp->_seek64;