1/*	$OpenBSD: stdio.c,v 1.9 2005/08/08 08:05:36 espie 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 <fcntl.h>
35#include <unistd.h>
36#include <stdio.h>
37#include "local.h"
38
39/*
40 * Small standard I/O/seek/close functions.
41 * These maintain the `known seek offset' for seek optimisation.
42 */
43int
44__sread(void *cookie, char *buf, int n)
45{
46	FILE *fp = cookie;
47	int ret;
48
49	ret = read(fp->_file, buf, n);
50	/* if the read succeeded, update the current offset */
51	if (ret >= 0)
52		fp->_offset += ret;
53	else
54		fp->_flags &= ~__SOFF;	/* paranoia */
55	return (ret);
56}
57
58int
59__swrite(void *cookie, const char *buf, int n)
60{
61	FILE *fp = cookie;
62
63	if (fp->_flags & __SAPP)
64		(void) lseek(fp->_file, (off_t)0, SEEK_END);
65	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
66	return (write(fp->_file, buf, n));
67}
68
69fpos_t
70__sseek(void *cookie, fpos_t offset, int whence)
71{
72	FILE *fp = cookie;
73	off_t ret;
74
75	ret = lseek(fp->_file, (off_t)offset, whence);
76	if (ret == (off_t)-1)
77		fp->_flags &= ~__SOFF;
78	else {
79		fp->_flags |= __SOFF;
80		fp->_offset = ret;
81	}
82	return (ret);
83}
84
85int
86__sclose(void *cookie)
87{
88	return (close(((FILE *)cookie)->_file));
89}
90