/*
 *  fwrite.c
 *
 *    (c)Copyright 1992-1997 Obvious Implementations Corp.  Redistribution and
 *    use is allowed under the terms of the DICE-LICENSE FILE,
 *    DICE-LICENSE.TXT.
 */

#include <fcntl.h>
#include <stdio.h>
#include <string.h>

#define buf ((const char *)vbuf)

size_t
fwrite(vbuf, elmsize, elms, fi)
const void *vbuf;
size_t elmsize;
size_t elms;
FILE *fi;
{
    int n = EOF;
    int bytes;

    if (elmsize == 1)
	bytes = elms;
    else if (elms == 1)
	bytes = elmsize;
    else
	bytes = elms * elmsize;

    if (fi == NULL)
	return(-1);
    if (fi->sd_Flags & __SIF_WRITE) {
	if (bytes > fi->sd_WLeft)
	    fflush(fi);             /*  also puts us into 'write' mode */

	if (bytes <= fi->sd_WLeft) {
	    movmem(buf, fi->sd_WPtr, bytes);
	    fi->sd_WLeft -= bytes;
	    fi->sd_WPtr += bytes;
	    n = bytes;

	    if ((fi->sd_Flags & __SIF_IOLBF) && bytes && buf[bytes-1] == '\n')
		fflush(fi);
	} else {
	    long w = bytes;

	    while (w > 0) {
		n = write(fi->sd_Fd, buf, w);
		if (n <= 0)
		    break;
		fi->sd_Offset += n;
		vbuf = buf + n;
		w -= n;
	    }
	}
    }
    if (n < 0)
	fi->sd_Error = EOF;
    if (fi->sd_Error)
	return(fi->sd_Error);
    if (n == bytes)
	return(elms);
    return(n / elmsize);
}