fwrite.c revision 249810
1127664Sbms/*- 2172677Smlaier * Copyright (c) 1990, 1993 3172677Smlaier * The Regents of the University of California. All rights reserved. 4127664Sbms * 5127664Sbms * This code is derived from software contributed to Berkeley by 6127664Sbms * Chris Torek. 7127664Sbms * 8127664Sbms * Redistribution and use in source and binary forms, with or without 9127664Sbms * modification, are permitted provided that the following conditions 10127664Sbms * are met: 11127664Sbms * 1. Redistributions of source code must retain the above copyright 12127664Sbms * notice, this list of conditions and the following disclaimer. 13127664Sbms * 2. Redistributions in binary form must reproduce the above copyright 14127664Sbms * notice, this list of conditions and the following disclaimer in the 15172677Smlaier * documentation and/or other materials provided with the distribution. 16172677Smlaier * 3. Neither the name of the University nor the names of its contributors 17172677Smlaier * may be used to endorse or promote products derived from this software 18172677Smlaier * without specific prior written permission. 19127664Sbms * 20127664Sbms * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21127664Sbms * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22127664Sbms * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23127664Sbms * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24127664Sbms * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25127664Sbms * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26127664Sbms * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27127664Sbms * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28127664Sbms * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29127664Sbms * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30127664Sbms * SUCH DAMAGE. 31127664Sbms */ 32127664Sbms 33127664Sbms#if defined(LIBC_SCCS) && !defined(lint) 34127664Sbmsstatic char sccsid[] = "@(#)fwrite.c 8.1 (Berkeley) 6/4/93"; 35127664Sbms#endif /* LIBC_SCCS and not lint */ 36214518Srpaulo#include <sys/cdefs.h> 37127664Sbms__FBSDID("$FreeBSD: head/lib/libc/stdio/fwrite.c 249810 2013-04-23 14:36:44Z emaste $"); 38127664Sbms 39127664Sbms#include "namespace.h" 40127664Sbms#include <errno.h> 41127664Sbms#include <stdint.h> 42127664Sbms#include <stdio.h> 43127664Sbms#include "un-namespace.h" 44127664Sbms#include "local.h" 45172677Smlaier#include "fvwrite.h" 46127664Sbms#include "libc_private.h" 47127664Sbms 48127664Sbms/* 49127664Sbms * Write `count' objects (each size `size') from memory to the given file. 50127664Sbms * Return the number of whole objects written. 51127664Sbms */ 52127664Sbmssize_t 53127664Sbmsfwrite(const void * __restrict buf, size_t size, size_t count, FILE * __restrict fp) 54127664Sbms{ 55127664Sbms size_t n; 56127664Sbms struct __suio uio; 57127664Sbms struct __siov iov; 58127664Sbms 59127664Sbms /* 60127664Sbms * ANSI and SUSv2 require a return value of 0 if size or count are 0. 61127664Sbms */ 62127664Sbms if ((count == 0) || (size == 0)) 63127664Sbms return (0); 64127664Sbms 65127664Sbms /* 66127664Sbms * Check for integer overflow. As an optimization, first check that 67127664Sbms * at least one of {count, size} is at least 2^16, since if both 68127664Sbms * values are less than that, their product can't possible overflow 69127664Sbms * (size_t is always at least 32 bits on FreeBSD). 70127664Sbms */ 71127664Sbms if (((count | size) > 0xFFFF) && 72127664Sbms (count > SIZE_MAX / size)) { 73127664Sbms errno = EINVAL; 74127664Sbms fp->_flags |= __SERR; 75127664Sbms return (0); 76127664Sbms } 77127664Sbms 78127664Sbms n = count * size; 79127664Sbms 80127664Sbms iov.iov_base = (void *)buf; 81127664Sbms uio.uio_resid = iov.iov_len = n; 82127664Sbms uio.uio_iov = &iov; 83127664Sbms uio.uio_iovcnt = 1; 84127664Sbms 85127664Sbms FLOCKFILE(fp); 86127664Sbms ORIENT(fp, -1); 87127664Sbms /* 88127664Sbms * The usual case is success (__sfvwrite returns 0); 89127664Sbms * skip the divide if this happens, since divides are 90127664Sbms * generally slow and since this occurs whenever size==0. 91127664Sbms */ 92127664Sbms if (__sfvwrite(fp, &uio) != 0) 93127664Sbms count = (n - uio.uio_resid) / size; 94127664Sbms FUNLOCKFILE(fp); 95127664Sbms return (count); 96127664Sbms} 97127664Sbms