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      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
     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 
     49 	iov.iov_base = (void *)buf;
     50 	uio.uio_resid = iov.iov_len = n = count * size;
     51 	uio.uio_iov = &iov;
     52 	uio.uio_iovcnt = 1;
     53 
     54 	/*
     55 	 * The usual case is success (__sfvwrite returns 0);
     56 	 * skip the divide if this happens, since divides are
     57 	 * generally slow and since this occurs whenever size==0.
     58 	 */
     59 	if (__sfvwrite(fp, &uio) == 0)
     60 		return (count);
     61 	return ((n - uio.uio_resid) / size);
     62 }
     63