diff options
Diffstat (limited to 'lib/fpurge.c')
| -rw-r--r-- | lib/fpurge.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/lib/fpurge.c b/lib/fpurge.c new file mode 100644 index 0000000..21e3b86 --- /dev/null +++ b/lib/fpurge.c @@ -0,0 +1,150 @@ +/* Flushing buffers of a FILE stream. + Copyright (C) 2007-2022 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> + +#if HAVE___FPURGE /* glibc >= 2.2, Haiku, Solaris >= 7, UnixWare >= 7.1.4.MP4, Cygwin >= 1.7.10, Android API >= 23, musl libc */ +# if HAVE_STDIO_EXT_H +# include <stdio_ext.h> +# endif +#endif +#include <stdlib.h> + +#include "stdio-impl.h" + +int +fpurge (FILE *fp) +{ +#if HAVE___FPURGE /* glibc >= 2.2, Haiku, Solaris >= 7, UnixWare >= 7.1.4.MP4, Cygwin >= 1.7.10, Android API >= 23, musl libc */ + + __fpurge (fp); + /* The __fpurge function does not have a return value. */ + return 0; + +#elif HAVE_FPURGE /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin >= 1.7 */ + + /* Call the system's fpurge function. */ +# undef fpurge +# if !HAVE_DECL_FPURGE + extern int fpurge (FILE *); +# endif + int result = fpurge (fp); +# if defined __sferror || defined __DragonFly__ || defined __ANDROID__ + /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */ + if (result == 0) + /* Correct the invariants that fpurge broke. + <stdio.h> on BSD systems says: + "The following always hold: if _flags & __SRD, _w is 0." + If this invariant is not fulfilled and the stream is read-write but + currently reading, subsequent putc or fputc calls will write directly + into the buffer, although they shouldn't be allowed to. */ + if ((fp_->_flags & __SRD) != 0) + fp_->_w = 0; +# endif + return result; + +#else + + /* Most systems provide FILE as a struct and the necessary bitmask in + <stdio.h>, because they need it for implementing getc() and putc() as + fast macros. */ +# if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 + /* GNU libc, BeOS, Haiku, Linux libc5 */ + fp->_IO_read_end = fp->_IO_read_ptr; + fp->_IO_write_ptr = fp->_IO_write_base; + /* Avoid memory leak when there is an active ungetc buffer. */ + if (fp->_IO_save_base != NULL) + { + free (fp->_IO_save_base); + fp->_IO_save_base = NULL; + } + return 0; +# elif defined __sferror || defined __DragonFly__ || defined __ANDROID__ + /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin, Minix 3, Android */ + 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); + /* Avoid memory leak when there is an active ungetc buffer. */ + if (fp_ub._base != NULL) + { + if (fp_ub._base != fp_->_ubuf) + free (fp_ub._base); + fp_ub._base = NULL; + } + return 0; +# elif defined __EMX__ /* emx+gcc */ + fp->_ptr = fp->_buffer; + fp->_rcount = 0; + fp->_wcount = 0; + fp->_ungetc_count = 0; + return 0; +# elif defined __minix /* Minix */ + fp->_ptr = fp->_buf; + if (fp->_ptr != NULL) + fp->_count = 0; + return 0; +# elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */ + fp_->_ptr = fp_->_base; + if (fp_->_ptr != NULL) + fp_->_cnt = 0; + return 0; +# elif defined __UCLIBC__ /* uClibc */ +# ifdef __STDIO_BUFFERS + if (fp->__modeflags & __FLAG_WRITING) + fp->__bufpos = fp->__bufstart; + else if (fp->__modeflags & (__FLAG_READONLY | __FLAG_READING)) + fp->__bufpos = fp->__bufread; +# endif + return 0; +# elif defined __QNX__ /* QNX */ + fp->_Rback = fp->_Back + sizeof (fp->_Back); + fp->_Rsave = NULL; + if (fp->_Mode & 0x2000 /* _MWRITE */) + /* fp->_Buf <= fp->_Next <= fp->_Wend */ + fp->_Next = fp->_Buf; + else + /* fp->_Buf <= fp->_Next <= fp->_Rend */ + fp->_Rend = fp->_Next; + return 0; +# elif defined __MINT__ /* Atari FreeMiNT */ + if (fp->__pushed_back) + { + fp->__bufp = fp->__pushback_bufp; + fp->__pushed_back = 0; + } + /* Preserve the current file position. */ + if (fp->__target != -1) + fp->__target += fp->__bufp - fp->__buffer; + fp->__bufp = fp->__buffer; + /* Nothing in the buffer, next getc is nontrivial. */ + fp->__get_limit = fp->__bufp; + /* Nothing in the buffer, next putc is nontrivial. */ + fp->__put_limit = fp->__buffer; + return 0; +# elif defined EPLAN9 /* Plan9 */ + fp->rp = fp->wp = fp->lp = fp->buf; + return 0; +# else +# error "Please port gnulib fpurge.c to your platform! Look at the definitions of fflush, setvbuf and ungetc on your system, then report this to bug-gnulib." +# endif + +#endif +} |