1/*	$OpenBSD: stdio.c,v 1.10 2016/09/21 04:38:56 guenther Exp $ */
2/*-
3 * Copyright (c) 1990, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Chris Torek.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <stdio.h>
35#include <unistd.h>
36#include "local.h"
37
38/*
39 * Small standard I/O/seek/close functions.
40 * These maintain the `known seek offset' for seek optimisation.
41 */
42int
43__sread(void *cookie, char *buf, int n)
44{
45	FILE *fp = cookie;
46	int ret;
47
48	ret = read(fp->_file, buf, n);
49	/* if the read succeeded, update the current offset */
50	if (ret >= 0)
51		fp->_offset += ret;
52	else
53		fp->_flags &= ~__SOFF;	/* paranoia */
54	return (ret);
55}
56
57int
58__swrite(void *cookie, const char *buf, int n)
59{
60	FILE *fp = cookie;
61
62	if (fp->_flags & __SAPP)
63		(void) lseek(fp->_file, 0, SEEK_END);
64	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
65	return (write(fp->_file, buf, n));
66}
67
68fpos_t
69__sseek(void *cookie, fpos_t offset, int whence)
70{
71	FILE *fp = cookie;
72	off_t ret;
73
74	ret = lseek(fp->_file, offset, whence);
75	if (ret == -1)
76		fp->_flags &= ~__SOFF;
77	else {
78		fp->_flags |= __SOFF;
79		fp->_offset = ret;
80	}
81	return (ret);
82}
83
84int
85__sclose(void *cookie)
86{
87	return (close(((FILE *)cookie)->_file));
88}
89