fwrite.c revision 71579 
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)
38#if 0
39static char sccsid[] = "@(#)fwrite.c	8.1 (Berkeley) 6/4/93";
40#endif
41static const char rcsid[] =
42  "$FreeBSD: head/lib/libc/stdio/fwrite.c 71579 2001-01-24 13:01:12Z deischen $";
43#endif /* LIBC_SCCS and not lint */
44
45#include "namespace.h"
46#include <stdio.h>
47#include "un-namespace.h"
48#include "local.h"
49#include "fvwrite.h"
50#include "libc_private.h"
51
52/*
53 * Write `count' objects (each size `size') from memory to the given file.
54 * Return the number of whole objects written.
55 */
56size_t
57fwrite(buf, size, count, fp)
58	const void *buf;
59	size_t size, count;
60	FILE *fp;
61{
62	size_t n;
63	struct __suio uio;
64	struct __siov iov;
65
66	iov.iov_base = (void *)buf;
67	uio.uio_resid = iov.iov_len = n = count * size;
68	uio.uio_iov = &iov;
69	uio.uio_iovcnt = 1;
70
71	FLOCKFILE(fp);
72	/*
73	 * The usual case is success (__sfvwrite returns 0);
74	 * skip the divide if this happens, since divides are
75	 * generally slow and since this occurs whenever size==0.
76	 */
77	if (__sfvwrite(fp, &uio) != 0)
78	    count = (n - uio.uio_resid) / size;
79	FUNLOCKFILE(fp);
80	return (count);
81}
82