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
9 * modification, are permitted provided that the following conditions
10 * are met:
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 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if defined(LIBC_SCCS) && !defined(lint)
38static char rcsid[] = "$OpenBSD: fflush.c,v 1.2 1996/08/19 08:32:26 tholo Exp $";
39#endif /* LIBC_SCCS and not lint */
40
41#include <errno.h>
42#include <stdio.h>
43
44#include <errno_private.h>
45
46#include "local.h"
47
48/* Flush a single file, or (if fp is NULL) all files.  */
49int
50fflush(fp)
51	register FILE *fp;
52{
53	if (fp == NULL)
54		return (_fwalk(__sflush));
55	if ((fp->_flags & (__SWR | __SRW)) == 0) {
56		__set_errno(EBADF);
57		return (EOF);
58	}
59	return (__sflush(fp));
60}
61
62int
63__sflush(fp)
64	register FILE *fp;
65{
66	register unsigned char *p;
67	register int n, t;
68
69	t = fp->_flags;
70	if ((t & __SWR) == 0)
71		return (0);
72
73	if ((p = fp->_bf._base) == NULL)
74		return (0);
75
76	n = fp->_p - p;		/* write this much */
77
78	/*
79	 * Set these immediately to avoid problems with longjmp and to allow
80	 * exchange buffering (via setvbuf) in user write function.
81	 */
82	fp->_p = p;
83	fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
84
85	for (; n > 0; n -= t, p += t) {
86		t = (*fp->_write)(fp->_cookie, (char *)p, n);
87		if (t <= 0) {
88			fp->_flags |= __SERR;
89			return (EOF);
90		}
91	}
92	return (0);
93}
94