[apple/libc.git] / stdio / FreeBSD / fread.c

/*-
 * Copyright (c) 1990, 1993
 *	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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)fread.c	8.2 (Berkeley) 12/11/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/stdio/fread.c,v 1.12 2002/10/12 16:13:37 mike Exp $");

#include "namespace.h"
#include <stdio.h>
#include <string.h>
#include "un-namespace.h"
#include "local.h"
#include "libc_private.h"

size_t
fread(buf, size, count, fp)
	void * __restrict buf;
	size_t size, count;
	FILE * __restrict fp;
{
	size_t resid;
	char *p;
	int r;
	size_t total;

	/*
	 * The ANSI standard requires a return value of 0 for a count
	 * or a size of 0.  Peculiarily, it imposes no such requirements
	 * on fwrite; it only requires fread to be broken.
	 */
	if ((resid = count * size) == 0)
		return (0);
	FLOCKFILE(fp);
	ORIENT(fp, -1);
	if (fp->_r < 0)
		fp->_r = 0;
	total = resid;
	p = buf;
	while (resid > (r = fp->_r)) {
		(void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
		fp->_p += r;
		/* fp->_r = 0 ... done in __srefill */
		p += r;
		resid -= r;
		if (__srefill(fp)) {
			/* no more input: return partial result */
			FUNLOCKFILE(fp);
			return ((total - resid) / size);
		}
	}
	(void)memcpy((void *)p, (void *)fp->_p, resid);
	fp->_r -= resid;
	fp->_p += resid;
	FUNLOCKFILE(fp);
	return (count);
}
Commit	Line	Data
9385eb3d	1	/*-
e9ce8d39 A	2	* Copyright (c) 1990, 1993
	3	* The Regents of the University of California. 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
9385eb3d A	37	#if defined(LIBC_SCCS) && !defined(lint)
	38	static char sccsid[] = "@(#)fread.c 8.2 (Berkeley) 12/11/93";
	39	#endif /* LIBC_SCCS and not lint */
	40	#include <sys/cdefs.h>
	41	__FBSDID("$FreeBSD: src/lib/libc/stdio/fread.c,v 1.12 2002/10/12 16:13:37 mike Exp $");
e9ce8d39	42
9385eb3d	43	#include "namespace.h"
e9ce8d39 A	44	#include <stdio.h>
e9ce8d39 A	45	#include <string.h>
9385eb3d A	46	#include "un-namespace.h"
	47	#include "local.h"
	48	#include "libc_private.h"
e9ce8d39 A	49
	50	size_t
	51	fread(buf, size, count, fp)
9385eb3d	52	void * __restrict buf;
e9ce8d39	53	size_t size, count;
9385eb3d	54	FILE * __restrict fp;
e9ce8d39	55	{
9385eb3d A	56	size_t resid;
	57	char *p;
	58	int r;
e9ce8d39 A	59	size_t total;
	60
	61	/*
	62	* The ANSI standard requires a return value of 0 for a count
	63	* or a size of 0. Peculiarily, it imposes no such requirements
	64	* on fwrite; it only requires fread to be broken.
	65	*/
	66	if ((resid = count * size) == 0)
	67	return (0);
9385eb3d A	68	FLOCKFILE(fp);
9385eb3d A	69	ORIENT(fp, -1);
e9ce8d39 A	70	if (fp->_r < 0)
	71	fp->_r = 0;
	72	total = resid;
	73	p = buf;
	74	while (resid > (r = fp->_r)) {
	75	(void)memcpy((void )p, (void )fp->_p, (size_t)r);
	76	fp->_p += r;
	77	/* fp->_r = 0 ... done in __srefill */
	78	p += r;
	79	resid -= r;
	80	if (__srefill(fp)) {
	81	/* no more input: return partial result */
9385eb3d	82	FUNLOCKFILE(fp);
e9ce8d39 A	83	return ((total - resid) / size);
	84	}
	85	}
	86	(void)memcpy((void )p, (void )fp->_p, resid);
	87	fp->_r -= resid;
	88	fp->_p += resid;
9385eb3d	89	FUNLOCKFILE(fp);
e9ce8d39 A	90	return (count);
e9ce8d39 A	91	}