stdio.c revision 56698 
1/*-
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
37#if defined(LIBC_SCCS) && !defined(lint)
38#if 0
39static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
40#endif
41static const char rcsid[] =
42  "$FreeBSD: head/lib/libc/stdio/stdio.c 56698 2000-01-27 23:07:25Z jasone $";
43#endif /* LIBC_SCCS and not lint */
44
45#include <fcntl.h>
46#include <unistd.h>
47#include <stdio.h>
48#include "local.h"
49
50/*
51 * Small standard I/O/seek/close functions.
52 * These maintain the `known seek offset' for seek optimisation.
53 */
54int
55__sread(cookie, buf, n)
56	void *cookie;
57	char *buf;
58	int n;
59{
60	register FILE *fp = cookie;
61	register int ret;
62
63	ret = _read(fp->_file, buf, (size_t)n);
64	/* if the read succeeded, update the current offset */
65	if (ret >= 0)
66		fp->_offset += ret;
67	else
68		fp->_flags &= ~__SOFF;	/* paranoia */
69	return (ret);
70}
71
72int
73__swrite(cookie, buf, n)
74	void *cookie;
75	char const *buf;
76	int n;
77{
78	register FILE *fp = cookie;
79
80	if (fp->_flags & __SAPP)
81		(void) lseek(fp->_file, (off_t)0, SEEK_END);
82	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
83	return (_write(fp->_file, buf, (size_t)n));
84}
85
86fpos_t
87__sseek(cookie, offset, whence)
88	void *cookie;
89	fpos_t offset;
90	int whence;
91{
92	register FILE *fp = cookie;
93	register off_t ret;
94
95	ret = lseek(fp->_file, (off_t)offset, whence);
96	if (ret == -1)
97		fp->_flags &= ~__SOFF;
98	else {
99		fp->_flags |= __SOFF;
100		fp->_offset = ret;
101	}
102	return (ret);
103}
104
105int
106__sclose(cookie)
107	void *cookie;
108{
109
110	return (_close(((FILE *)cookie)->_file));
111}
112