1 /* $OpenBSD: fwrite.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */
2 /*-
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Chris Torek.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <stdio.h>
35 #include "local.h"
36 #include "fvwrite.h"
37
38 /*
39 * Write `count' objects (each size `size') from memory to the given file.
40 * Return the number of whole objects written.
41 */
42 size_t
fwrite(const void * buf,size_t size,size_t count,FILE * fp)43 fwrite(const void *buf, size_t size, size_t count, FILE *fp)
44 {
45 size_t n;
46 struct __suio uio;
47 struct __siov iov;
48 int ret;
49
50 iov.iov_base = (void *)buf;
51 uio.uio_resid = iov.iov_len = n = count * size;
52 uio.uio_iov = &iov;
53 uio.uio_iovcnt = 1;
54
55 /*
56 * The usual case is success (__sfvwrite returns 0);
57 * skip the divide if this happens, since divides are
58 * generally slow and since this occurs whenever size==0.
59 */
60 FLOCKFILE(fp);
61 ret = __sfvwrite(fp, &uio);
62 FUNLOCKFILE(fp);
63 if (ret == 0)
64 return (count);
65 return ((n - uio.uio_resid) / size);
66 }
67