1219820Sjeff/* Flushing buffers of a FILE stream. 2219820Sjeff Copyright (C) 2007-2010 Free Software Foundation, Inc. 3219820Sjeff 4219820Sjeff This program is free software: you can redistribute it and/or modify 5219820Sjeff it under the terms of the GNU General Public License as published by 6219820Sjeff the Free Software Foundation; either version 3 of the License, or 7219820Sjeff (at your option) any later version. 8219820Sjeff 9219820Sjeff This program is distributed in the hope that it will be useful, 10219820Sjeff but WITHOUT ANY WARRANTY; without even the implied warranty of 11219820Sjeff MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12219820Sjeff GNU General Public License for more details. 13219820Sjeff 14219820Sjeff You should have received a copy of the GNU General Public License 15219820Sjeff along with this program. If not, see <http://www.gnu.org/licenses/>. */ 16219820Sjeff 17219820Sjeff#include <config.h> 18219820Sjeff 19219820Sjeff/* Specification. */ 20219820Sjeff#include <stdio.h> 21219820Sjeff 22219820Sjeff#if HAVE___FPURGE /* glibc >= 2.2, Haiku, Solaris >= 7 */ 23219820Sjeff# include <stdio_ext.h> 24219820Sjeff#endif 25219820Sjeff#include <stdlib.h> 26219820Sjeff 27219820Sjeff#include "stdio-impl.h" 28219820Sjeff 29219820Sjeffint 30219820Sjefffpurge (FILE *fp) 31219820Sjeff{ 32219820Sjeff#if HAVE___FPURGE /* glibc >= 2.2, Haiku, Solaris >= 7 */ 33219820Sjeff 34219820Sjeff __fpurge (fp); 35219820Sjeff /* The __fpurge function does not have a return value. */ 36219820Sjeff return 0; 37219820Sjeff 38219820Sjeff#elif HAVE_FPURGE /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin 1.7 */ 39219820Sjeff 40219820Sjeff /* Call the system's fpurge function. */ 41219820Sjeff# undef fpurge 42219820Sjeff# if !HAVE_DECL_FPURGE 43219820Sjeff extern int fpurge (FILE *); 44219820Sjeff# endif 45219820Sjeff int result = fpurge (fp); 46219820Sjeff# if defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */ 47219820Sjeff if (result == 0) 48219820Sjeff /* Correct the invariants that fpurge broke. 49219820Sjeff <stdio.h> on BSD systems says: 50219820Sjeff "The following always hold: if _flags & __SRD, _w is 0." 51219820Sjeff If this invariant is not fulfilled and the stream is read-write but 52219820Sjeff currently reading, subsequent putc or fputc calls will write directly 53219820Sjeff into the buffer, although they shouldn't be allowed to. */ 54219820Sjeff if ((fp_->_flags & __SRD) != 0) 55219820Sjeff fp_->_w = 0; 56219820Sjeff# endif 57219820Sjeff return result; 58219820Sjeff 59219820Sjeff#else 60219820Sjeff 61219820Sjeff /* Most systems provide FILE as a struct and the necessary bitmask in 62219820Sjeff <stdio.h>, because they need it for implementing getc() and putc() as 63219820Sjeff fast macros. */ 64219820Sjeff# if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */ 65219820Sjeff fp->_IO_read_end = fp->_IO_read_ptr; 66219820Sjeff fp->_IO_write_ptr = fp->_IO_write_base; 67219820Sjeff /* Avoid memory leak when there is an active ungetc buffer. */ 68219820Sjeff if (fp->_IO_save_base != NULL) 69219820Sjeff { 70219820Sjeff free (fp->_IO_save_base); 71219820Sjeff fp->_IO_save_base = NULL; 72219820Sjeff } 73219820Sjeff return 0; 74219820Sjeff# elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */ 75219820Sjeff fp_->_p = fp_->_bf._base; 76219820Sjeff fp_->_r = 0; 77219820Sjeff fp_->_w = ((fp_->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully buffered and not currently reading? */ 78219820Sjeff ? fp_->_bf._size 79219820Sjeff : 0); 80219820Sjeff /* Avoid memory leak when there is an active ungetc buffer. */ 81219820Sjeff if (fp_ub._base != NULL) 82219820Sjeff { 83219820Sjeff if (fp_ub._base != fp_->_ubuf) 84219820Sjeff free (fp_ub._base); 85219820Sjeff fp_ub._base = NULL; 86219820Sjeff } 87219820Sjeff return 0; 88219820Sjeff# elif defined __EMX__ /* emx+gcc */ 89219820Sjeff fp->_ptr = fp->_buffer; 90219820Sjeff fp->_rcount = 0; 91219820Sjeff fp->_wcount = 0; 92219820Sjeff fp->_ungetc_count = 0; 93219820Sjeff return 0; 94219820Sjeff# elif defined _IOERR /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw */ 95219820Sjeff fp->_ptr = fp->_base; 96219820Sjeff if (fp->_ptr != NULL) 97219820Sjeff fp->_cnt = 0; 98219820Sjeff return 0; 99219820Sjeff# elif defined __UCLIBC__ /* uClibc */ 100219820Sjeff# ifdef __STDIO_BUFFERS 101219820Sjeff if (fp->__modeflags & __FLAG_WRITING) 102219820Sjeff fp->__bufpos = fp->__bufstart; 103219820Sjeff else if (fp->__modeflags & (__FLAG_READONLY | __FLAG_READING)) 104219820Sjeff fp->__bufpos = fp->__bufread; 105219820Sjeff# endif 106219820Sjeff return 0; 107219820Sjeff# elif defined __QNX__ /* QNX */ 108219820Sjeff fp->_Rback = fp->_Back + sizeof (fp->_Back); 109219820Sjeff fp->_Rsave = NULL; 110219820Sjeff if (fp->_Mode & 0x2000 /* _MWRITE */) 111219820Sjeff /* fp->_Buf <= fp->_Next <= fp->_Wend */ 112219820Sjeff fp->_Next = fp->_Buf; 113219820Sjeff else 114219820Sjeff /* fp->_Buf <= fp->_Next <= fp->_Rend */ 115219820Sjeff fp->_Rend = fp->_Next; 116219820Sjeff return 0; 117219820Sjeff# elif defined __MINT__ /* Atari FreeMiNT */ 118219820Sjeff if (fp->__pushed_back) 119219820Sjeff { 120219820Sjeff fp->__bufp = fp->__pushback_bufp; 121219820Sjeff fp->__pushed_back = 0; 122219820Sjeff } 123219820Sjeff /* Preserve the current file position. */ 124219820Sjeff if (fp->__target != -1) 125219820Sjeff fp->__target += fp->__bufp - fp->__buffer; 126219820Sjeff fp->__bufp = fp->__buffer; 127219820Sjeff /* Nothing in the buffer, next getc is nontrivial. */ 128219820Sjeff fp->__get_limit = fp->__bufp; 129219820Sjeff /* Nothing in the buffer, next putc is nontrivial. */ 130219820Sjeff fp->__put_limit = fp->__buffer; 131219820Sjeff return 0; 132219820Sjeff# else 133219820Sjeff #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." 134219820Sjeff# endif 135219820Sjeff 136219820Sjeff#endif 137219820Sjeff} 138219820Sjeff