1/*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without --- 20 unchanged lines hidden (view full) --- 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93"; 35#endif /* LIBC_SCCS and not lint */ 36#include <sys/cdefs.h> |
37__FBSDID("$FreeBSD: head/lib/libc/stdio/fflush.c 268924 2014-07-20 20:05:39Z pfg $"); |
38 39#include "namespace.h" 40#include <errno.h> 41#include <stdio.h> 42#include "un-namespace.h" 43#include "libc_private.h" 44#include "local.h" 45 --- 9 unchanged lines hidden (view full) --- 55 int retval; 56 57 if (fp == NULL) 58 return (_fwalk(sflush_locked)); 59 FLOCKFILE(fp); 60 61 /* 62 * There is disagreement about the correct behaviour of fflush() |
63 * when passed a file which is not open for writing. According to |
64 * the ISO C standard, the behaviour is undefined. 65 * Under linux, such an fflush returns success and has no effect; 66 * under Windows, such an fflush is documented as behaving instead 67 * as fpurge(). 68 * Given that applications may be written with the expectation of 69 * either of these two behaviours, the only safe (non-astonishing) 70 * option is to return EBADF and ask that applications be fixed. |
71 * SUSv3 now requires that fflush() returns success on a read-only 72 * stream. 73 * |
74 */ |
75 if ((fp->_flags & (__SWR | __SRW)) == 0) 76 retval = 0; 77 else |
78 retval = __sflush(fp); 79 FUNLOCKFILE(fp); 80 return (retval); 81} 82 83/* 84 * Flush a single file, or (if fp is NULL) all files. 85 * Non-MT-safe version 86 */ 87int 88__fflush(FILE *fp) 89{ 90 int retval; 91 92 if (fp == NULL) 93 return (_fwalk(sflush_locked)); |
94 if ((fp->_flags & (__SWR | __SRW)) == 0) 95 retval = 0; 96 else |
97 retval = __sflush(fp); 98 return (retval); 99} 100 101int 102__sflush(FILE *fp) 103{ 104 unsigned char *p; --- 13 unchanged lines hidden (view full) --- 118 * exchange buffering (via setvbuf) in user write function. 119 */ 120 fp->_p = p; 121 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 122 123 for (; n > 0; n -= t, p += t) { 124 t = _swrite(fp, (char *)p, n); 125 if (t <= 0) { |
126 /* Reset _p and _w. */ 127 if (p > fp->_p) /* Some was written. */ 128 memmove(fp->_p, p, n); 129 fp->_p += n; 130 if ((fp->_flags & (__SLBF | __SNBF)) == 0) 131 fp->_w -= n; |
132 fp->_flags |= __SERR; 133 return (EOF); 134 } 135 } 136 return (0); 137} 138 139static int 140sflush_locked(FILE *fp) 141{ 142 int ret; 143 144 FLOCKFILE(fp); 145 ret = __sflush(fp); 146 FUNLOCKFILE(fp); 147 return (ret); 148} |