usr/src/lib/libc/stdio/fwrite.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)fwrite.c    5.5 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <stdio.h>
#include "local.h"
#include "fvwrite.h"

/*
 * Write `count' objects (each size `size') from memory to the given file.
 * Return the number of whole objects written.
 */
fwrite(buf, size, count, fp)
        const void *buf;
        size_t size, count;
        FILE *fp;
{
        size_t n;
        struct __suio uio;
        struct __siov iov;

        iov.iov_base = (void *)buf;
        uio.uio_resid = iov.iov_len = n = count * size;
        uio.uio_iov = &iov;
        uio.uio_iovcnt = 1;

        /*
         * The usual case is success (__sfvwrite returns 0);
         * skip the divide if this happens, since divides are
         * generally slow and since this occurs whenever size==0.
         */
        if (__sfvwrite(fp, &uio) == 0)
                return (count);
        return ((n - uio.uio_resid) / size);
}