1/*	$NetBSD: stdio.c,v 1.21 2012/03/27 15:05:42 christos Exp $	*/
2
3/*-
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36#if defined(LIBC_SCCS) && !defined(lint)
37#if 0
38static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
39#else
40__RCSID("$NetBSD: stdio.c,v 1.21 2012/03/27 15:05:42 christos Exp $");
41#endif
42#endif /* LIBC_SCCS and not lint */
43
44#include "namespace.h"
45
46#include <assert.h>
47#include <errno.h>
48#include <fcntl.h>
49#include <stdio.h>
50#include <unistd.h>
51
52#include "reentrant.h"
53#include "local.h"
54
55/*
56 * Small standard I/O/seek/close functions.
57 * These maintain the `known seek offset' for seek optimisation.
58 */
59ssize_t
60__sread(void *cookie, void *buf, size_t n)
61{
62	FILE *fp = cookie;
63	ssize_t ret;
64
65	_DIAGASSERT(cookie != NULL);
66	_DIAGASSERT(cookie == fp->_cookie);
67	_DIAGASSERT(buf != NULL);
68
69	ret = read(__sfileno(fp), buf, n);
70	/* if the read succeeded, update the current offset */
71	if (ret >= 0)
72		fp->_offset += ret;
73	else
74		fp->_flags &= ~__SOFF;	/* paranoia */
75
76	return ret;
77}
78
79ssize_t
80__swrite(void *cookie, const void *buf, size_t n)
81{
82	FILE *fp = cookie;
83
84	_DIAGASSERT(cookie != NULL);
85	_DIAGASSERT(cookie == fp->_cookie);
86	_DIAGASSERT(buf != NULL);
87
88	if (fp->_flags & __SAPP)
89		if (lseek(__sfileno(fp), (off_t)0, SEEK_END) == (off_t)-1) {
90			if (errno == ESPIPE)            /* if unseekable, OK, */
91				fp->_flags &= ~__SAPP;  /* all writes append. */
92			else
93				return -1;
94		}
95	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
96	return write(__sfileno(fp), buf, n);
97}
98
99off_t
100__sseek(void *cookie, off_t offset, int whence)
101{
102	FILE *fp = cookie;
103	off_t ret;
104
105	_DIAGASSERT(cookie != NULL);
106	_DIAGASSERT(cookie == fp->_cookie);
107
108	ret = lseek(__sfileno(fp), offset, whence);
109	if (ret == (off_t)-1L)
110		fp->_flags &= ~__SOFF;
111	else {
112		fp->_flags |= __SOFF;
113		fp->_offset = ret;
114	}
115	return ret;
116}
117
118int
119__sclose(void *cookie)
120{
121	FILE *fp = cookie;
122
123	_DIAGASSERT(cookie != NULL);
124	_DIAGASSERT(cookie == fp->_cookie);
125
126	return close(__sfileno(fp));
127}
128