1 /* $NetBSD: fwrite.c,v 1.13 2001/01/25 02:06:25 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)fwrite.c 8.1 (Berkeley) 6/4/93"; 43 #else 44 __RCSID("$NetBSD: fwrite.c,v 1.13 2001/01/25 02:06:25 lukem Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <assert.h> 49 #include <errno.h> 50 #include <stdio.h> 51 #include "local.h" 52 #include "fvwrite.h" 53 #include "reentrant.h" 54 55 /* 56 * Write `count' objects (each size `size') from memory to the given file. 57 * Return the number of whole objects written. 58 */ 59 size_t 60 fwrite(buf, size, count, fp) 61 const void *buf; 62 size_t size, count; 63 FILE *fp; 64 { 65 size_t n; 66 struct __suio uio; 67 struct __siov iov; 68 69 _DIAGASSERT(fp != NULL); 70 /* 71 * SUSv2 requires a return value of 0 for a count or a size of 0. 72 */ 73 if ((n = count * size) == 0) 74 return (0); 75 _DIAGASSERT(buf != NULL); 76 77 /* LINTED we don't play with buf */ 78 iov.iov_base = (void *)buf; 79 uio.uio_resid = iov.iov_len = n; 80 uio.uio_iov = &iov; 81 uio.uio_iovcnt = 1; 82 83 /* 84 * The usual case is success (__sfvwrite returns 0); 85 * skip the divide if this happens, since divides are 86 * generally slow and since this occurs whenever size==0. 87 */ 88 FLOCKFILE(fp); 89 if (__sfvwrite(fp, &uio) != 0) 90 count = ((n - uio.uio_resid) / size); 91 FUNLOCKFILE(fp); 92 return (count); 93 } 94