Home | History | Annotate | Line # | Download | only in stdio
fwrite.c revision 1.4 
      1 /*-
      2  * Copyright (c) 1990 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Chris Torek.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 /*static char *sccsid = "from: @(#)fwrite.c	5.5 (Berkeley) 2/24/91";*/
     39 static char *rcsid = "$Id: fwrite.c,v 1.4 1993/10/04 18:51:13 jtc Exp $";
     40 #endif /* LIBC_SCCS and not lint */
     41 
     42 #include <stdio.h>
     43 #include "local.h"
     44 #include "fvwrite.h"
     45 
     46 /*
     47  * Write `count' objects (each size `size') from memory to the given file.
     48  * Return the number of whole objects written.
     49  */
     50 size_t
     51 fwrite(buf, size, count, fp)
     52 	const void *buf;
     53 	size_t size, count;
     54 	FILE *fp;
     55 {
     56 	size_t n;
     57 	struct __suio uio;
     58 	struct __siov iov;
     59 
     60 	iov.iov_base = (void *)buf;
     61 	uio.uio_resid = iov.iov_len = n = count * size;
     62 	uio.uio_iov = &iov;
     63 	uio.uio_iovcnt = 1;
     64 
     65 	/*
     66 	 * The usual case is success (__sfvwrite returns 0);
     67 	 * skip the divide if this happens, since divides are
     68 	 * generally slow and since this occurs whenever size==0.
     69 	 */
     70 	if (__sfvwrite(fp, &uio) == 0)
     71 		return (count);
     72 	return ((n - uio.uio_resid) / size);
     73 }
     74