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/* An fseeko() function that, together with fflush(), is POSIX compliant.
Copyright (C) 2007-2017 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, see <https://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include <stdio.h>
/* Get off_t, lseek, _POSIX_VERSION. */
#include <unistd.h>
#include "stdio-impl.h"
int
fseeko (FILE *fp, off_t offset, int whence)
#undef fseeko
#if !HAVE_FSEEKO
# undef fseek
# define fseeko fseek
#endif
#if _GL_WINDOWS_64_BIT_OFF_T
# undef fseeko
# if HAVE__FSEEKI64 /* msvc, mingw64 */
# define fseeko _fseeki64
# else /* mingw */
# define fseeko fseeko64
# endif
#endif
{
#if LSEEK_PIPE_BROKEN
/* mingw gives bogus answers rather than failure on non-seekable files. */
if (lseek (fileno (fp), 0, SEEK_CUR) == -1)
return EOF;
#endif
/* These tests are based on fpurge.c. */
#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
if (fp->_IO_read_end == fp->_IO_read_ptr
&& fp->_IO_write_ptr == fp->_IO_write_base
&& fp->_IO_save_base == NULL)
#elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
/* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
# if defined __SL64 && defined __SCLE /* Cygwin */
if ((fp->_flags & __SL64) == 0)
{
/* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
mode; but has an fseeko that requires 64-bit mode. */
FILE *tmp = fopen ("/dev/null", "r");
if (!tmp)
return -1;
fp->_flags |= __SL64;
fp->_seek64 = tmp->_seek64;
fclose (tmp);
}
# endif
if (fp_->_p == fp_->_bf._base
&& fp_->_r == 0
&& fp_->_w == ((fp_->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully buffered and not currently reading? */
? fp_->_bf._size
: 0)
&& fp_ub._base == NULL)
#elif defined __EMX__ /* emx+gcc */
if (fp->_ptr == fp->_buffer
&& fp->_rcount == 0
&& fp->_wcount == 0
&& fp->_ungetc_count == 0)
#elif defined __minix /* Minix */
if (fp_->_ptr == fp_->_buf
&& (fp_->_ptr == NULL || fp_->_count == 0))
#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw, MSVC, NonStop Kernel, OpenVMS */
if (fp_->_ptr == fp_->_base
&& (fp_->_ptr == NULL || fp_->_cnt == 0))
#elif defined __UCLIBC__ /* uClibc */
if (((fp->__modeflags & __FLAG_WRITING) == 0
|| fp->__bufpos == fp->__bufstart)
&& ((fp->__modeflags & (__FLAG_READONLY | __FLAG_READING)) == 0
|| fp->__bufpos == fp->__bufread))
#elif defined __QNX__ /* QNX */
if ((fp->_Mode & 0x2000 /* _MWRITE */ ? fp->_Next == fp->_Buf : fp->_Next == fp->_Rend)
&& fp->_Rback == fp->_Back + sizeof (fp->_Back)
&& fp->_Rsave == NULL)
#elif defined __MINT__ /* Atari FreeMiNT */
if (fp->__bufp == fp->__buffer
&& fp->__get_limit == fp->__bufp
&& fp->__put_limit == fp->__bufp
&& !fp->__pushed_back)
#elif defined EPLAN9 /* Plan9 */
if (fp->rp == fp->buf
&& fp->wp == fp->buf)
#elif FUNC_FFLUSH_STDIN < 0 && 200809 <= _POSIX_VERSION
/* Cross-compiling to some other system advertising conformance to
POSIX.1-2008 or later. Assume fseeko and fflush work as advertised.
If this assumption is incorrect, please report the bug to
bug-gnulib. */
if (0)
#else
#error "Please port gnulib fseeko.c to your platform! Look at the code in fseeko.c, then report this to bug-gnulib."
#endif
{
/* We get here when an fflush() call immediately preceded this one (or
if ftell() has created buffers but no I/O has occurred on a
newly-opened stream). We know there are no buffers. */
off_t pos = lseek (fileno (fp), offset, whence);
if (pos == -1)
{
#if defined __sferror || defined __DragonFly__ || defined __ANDROID__
/* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
fp_->_flags &= ~__SOFF;
#endif
return -1;
}
#if defined _IO_EOF_SEEN || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
fp->_flags &= ~_IO_EOF_SEEN;
fp->_offset = pos;
#elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
/* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */
# if defined __CYGWIN__ || (defined __NetBSD__ && __NetBSD_Version__ >= 600000000) || defined __minix
/* fp_->_offset is typed as an integer. */
fp_->_offset = pos;
# else
/* fp_->_offset is an fpos_t. */
{
/* Use a union, since on NetBSD, the compilation flags
determine whether fpos_t is typedef'd to off_t or a struct
containing a single off_t member. */
union
{
fpos_t f;
off_t o;
} u;
u.o = pos;
fp_->_offset = u.f;
}
# endif
fp_->_flags |= __SOFF;
fp_->_flags &= ~__SEOF;
#elif defined __EMX__ /* emx+gcc */
fp->_flags &= ~_IOEOF;
#elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw, MSVC, NonStop Kernel, OpenVMS */
fp_->_flag &= ~_IOEOF;
#elif defined __MINT__ /* Atari FreeMiNT */
fp->__offset = pos;
fp->__eof = 0;
#endif
return 0;
}
return fseeko (fp, offset, whence);
}
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