diff options
Diffstat (limited to 'lib/fseeko.c')
| -rw-r--r-- | lib/fseeko.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/lib/fseeko.c b/lib/fseeko.c new file mode 100644 index 0000000..89a7087 --- /dev/null +++ b/lib/fseeko.c @@ -0,0 +1,164 @@ +/* An fseeko() function that, together with fflush(), is POSIX compliant. + Copyright (C) 2007-2023 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser 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 && HAVE_DECL__FSEEKI64 /* msvc, mingw since msvcrt8.0, mingw64 */ +# define fseeko _fseeki64 +# else /* mingw before msvcrt8.0 */ +# 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 || defined _IO_ftrylockfile || __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, UnixWare, 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 || defined _IO_ftrylockfile || __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, UnixWare, 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); +} |