2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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33 #if defined(LIBC_SCCS) && !defined(lint)
34 static char sccsid[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93";
35 #endif /* LIBC_SCCS and not lint */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
39 #include "namespace.h"
42 #include "un-namespace.h"
43 #include "libc_private.h"
46 static int sflush_locked(FILE *);
49 * Flush a single file, or (if fp is NULL) all files.
58 return (_fwalk(sflush_locked));
62 * There is disagreement about the correct behaviour of fflush()
63 * when passed a file which is not open for reading. 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
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.
72 if ((fp->_flags & (__SWR | __SRW)) == 0) {
76 retval = __sflush(fp);
82 * Flush a single file, or (if fp is NULL) all files.
91 return (_fwalk(sflush_locked));
92 if ((fp->_flags & (__SWR | __SRW)) == 0) {
96 retval = __sflush(fp);
107 if ((t & __SWR) == 0)
110 if ((p = fp->_bf._base) == NULL)
113 n = fp->_p - p; /* write this much */
116 * Set these immediately to avoid problems with longjmp and to allow
117 * exchange buffering (via setvbuf) in user write function.
120 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
122 for (; n > 0; n -= t, p += t) {
123 t = _swrite(fp, (char *)p, n);
125 fp->_flags |= __SERR;
133 sflush_locked(FILE *fp)