fwrite.c revision 249808
11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1990, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * This code is derived from software contributed to Berkeley by 61573Srgrimes * Chris Torek. 71573Srgrimes * 81573Srgrimes * Redistribution and use in source and binary forms, with or without 91573Srgrimes * modification, are permitted provided that the following conditions 101573Srgrimes * are met: 111573Srgrimes * 1. Redistributions of source code must retain the above copyright 121573Srgrimes * notice, this list of conditions and the following disclaimer. 131573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141573Srgrimes * notice, this list of conditions and the following disclaimer in the 151573Srgrimes * documentation and/or other materials provided with the distribution. 16249808Semaste * 3. Neither the name of the University nor the names of its contributors 171573Srgrimes * may be used to endorse or promote products derived from this software 181573Srgrimes * without specific prior written permission. 191573Srgrimes * 201573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301573Srgrimes * SUCH DAMAGE. 311573Srgrimes */ 321573Srgrimes 331573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 341573Srgrimesstatic char sccsid[] = "@(#)fwrite.c 8.1 (Berkeley) 6/4/93"; 351573Srgrimes#endif /* LIBC_SCCS and not lint */ 3692986Sobrien#include <sys/cdefs.h> 3792986Sobrien__FBSDID("$FreeBSD: head/lib/libc/stdio/fwrite.c 249808 2013-04-23 13:33:13Z emaste $"); 381573Srgrimes 3971579Sdeischen#include "namespace.h" 40201999Scperciva#include <errno.h> 41201999Scperciva#include <stdint.h> 421573Srgrimes#include <stdio.h> 4371579Sdeischen#include "un-namespace.h" 441573Srgrimes#include "local.h" 451573Srgrimes#include "fvwrite.h" 4635129Sjb#include "libc_private.h" 471573Srgrimes 481573Srgrimes/* 491573Srgrimes * Write `count' objects (each size `size') from memory to the given file. 501573Srgrimes * Return the number of whole objects written. 511573Srgrimes */ 521573Srgrimessize_t 531573Srgrimesfwrite(buf, size, count, fp) 54104989Smike const void * __restrict buf; 551573Srgrimes size_t size, count; 56104989Smike FILE * __restrict fp; 571573Srgrimes{ 581573Srgrimes size_t n; 591573Srgrimes struct __suio uio; 601573Srgrimes struct __siov iov; 611573Srgrimes 62195637Sed /* 63195637Sed * ANSI and SUSv2 require a return value of 0 if size or count are 0. 64195637Sed */ 65201999Scperciva if ((count == 0) || (size == 0)) 66195637Sed return (0); 67195637Sed 68201999Scperciva /* 69201999Scperciva * Check for integer overflow. As an optimization, first check that 70201999Scperciva * at least one of {count, size} is at least 2^16, since if both 71201999Scperciva * values are less than that, their product can't possible overflow 72201999Scperciva * (size_t is always at least 32 bits on FreeBSD). 73201999Scperciva */ 74201999Scperciva if (((count | size) > 0xFFFF) && 75201999Scperciva (count > SIZE_MAX / size)) { 76201999Scperciva errno = EINVAL; 77201999Scperciva fp->_flags |= __SERR; 78201999Scperciva return (0); 79201999Scperciva } 80201999Scperciva 81201999Scperciva n = count * size; 82201999Scperciva 831573Srgrimes iov.iov_base = (void *)buf; 84195637Sed uio.uio_resid = iov.iov_len = n; 851573Srgrimes uio.uio_iov = &iov; 861573Srgrimes uio.uio_iovcnt = 1; 871573Srgrimes 8835129Sjb FLOCKFILE(fp); 89101776Stjr ORIENT(fp, -1); 901573Srgrimes /* 911573Srgrimes * The usual case is success (__sfvwrite returns 0); 921573Srgrimes * skip the divide if this happens, since divides are 931573Srgrimes * generally slow and since this occurs whenever size==0. 941573Srgrimes */ 9513545Sjulian if (__sfvwrite(fp, &uio) != 0) 9613545Sjulian count = (n - uio.uio_resid) / size; 9735129Sjb FUNLOCKFILE(fp); 9813545Sjulian return (count); 991573Srgrimes} 100