fwrite.c revision 22993 
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		"$Id$";
43#endif /* LIBC_SCCS and not lint */
44
45#include <stdio.h>
46#include "local.h"
47#include "fvwrite.h"
48#ifdef _THREAD_SAFE
49#include <pthread.h>
50#include "pthread_private.h"
51#endif
52
53/*
54 * Write `count' objects (each size `size') from memory to the given file.
55 * Return the number of whole objects written.
56 */
57size_t
58fwrite(buf, size, count, fp)
59	const void *buf;
60	size_t size, count;
61	FILE *fp;
62{
63	size_t n;
64	struct __suio uio;
65	struct __siov iov;
66
67	iov.iov_base = (void *)buf;
68	uio.uio_resid = iov.iov_len = n = count * size;
69	uio.uio_iov = &iov;
70	uio.uio_iovcnt = 1;
71
72#ifdef _THREAD_SAFE
73	_thread_flockfile(fp,__FILE__,__LINE__);
74#endif
75	/*
76	 * The usual case is success (__sfvwrite returns 0);
77	 * skip the divide if this happens, since divides are
78	 * generally slow and since this occurs whenever size==0.
79	 */
80	if (__sfvwrite(fp, &uio) != 0)
81	    count = (n - uio.uio_resid) / size;
82#ifdef _THREAD_SAFE
83	_thread_funlockfile(fp);
84#endif
85	return (count);
86}
87