/* fread.c - read a file. stdio.h *//* Copyright 1992-2002 Wind River Systems, Inc. *//*modification history--------------------01f,21jan02,jkf  SPR#72774, fread is checking for NULL on wrong arg01e,12dec01,jkf  fixing SPR#72128, fread should check for NULL before bcopy01d,10nov01,jkf  SPR#70967, fread returns wrong value when 3rd arg == 001c,05mar93,jdi  documentation cleanup for 5.1.01b,20sep92,smb  documentation additions01a,29jul92,jcf  Added OBJ_VERIFY	    smb  taken from UCB stdio*//*DESCRIPTION * 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. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in the *    documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software *    must display the following acknowledgement: *	This product includes software developed by the University of *	California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors *    may be used to endorse or promote products derived from this software *    without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE.INCLUDE FILE: stdio.h, string.hSEE ALSO: American National Standard X3.159-1989NOMANUAL*/#include "vxWorks.h"#include "stdio.h"#include "string.h"#include "objLib.h"#include "private/stdioP.h"/******************************************************************************** fread - read data into an array (ANSI)** This routine reads, into the array <buf>, up to <count> elements of size* <size>, from a specified stream <fp>.  The file position indicator for the* stream (if defined) is advanced by the number of characters successfully* read.  If an error occurs, the resulting value of the file position* indicator for the stream is indeterminate.  If a partial element is read,* its value is indeterminate.* * INCLUDE FILES: stdio.h ** RETURNS:* The number of elements successfully read, which may be less than <count>* if a read error or end-of-file is encountered; or zero if <size> or* <count> is zero, with the contents of the array and the state of the* stream remaining unchanged.*/int fread    (    void *	buf,	/* where to copy data */    size_t	size, 	/* element size */    size_t	count,	/* no. of elements */    FAST FILE *	fp	/* stream to read from */    )    {    FAST size_t resid;    FAST char *	p;    FAST int	r;    size_t	total;    /* SPR#72128, check for NULL args before bcopy */    if ((NULL == fp) || (NULL == buf))	{        return (0);	}    if (OBJ_VERIFY (fp, fpClassId) != OK)	return (0);    /*      * SPR#70967: fread returns wrong value when 3rd arg == 0      *     * ANSI specification declares fread() returns zero if size      * _or_ count is zero.  But the vxWorks implementation returned      * non-zero given the following input case:     *     * fread ( buf , 0 ,1 ,fp );     *     * Old (broken) code:     *     * if ((resid = (count * size)) == 0)     *     return (count);          *     * New (fixed) code:     *     * if (0 == (resid = (count * size)))     *     return (0);          */    if (0 == (resid = (count * size)))	return (0);    if (fp->_r < 0)	fp->_r = 0;    total = resid;    p	  = buf;    while (resid > (r = fp->_r)) 	{	(void) bcopy ((void *)fp->_p, (void *)p, (size_t)r);	fp->_p	+= r;	p	+= r;	resid	-= r;	if (__srefill (fp))				/* fp->_r = 0 is done */		return ((total - resid) / size);	/* partial result */	}    (void) bcopy ((void *)fp->_p, (void *)p, resid);    fp->_r	-= resid;    fp->_p	+= resid;    return (count);    }