xref: /netbsd-src/lib/libc/stdio/stdio.c (revision 6a9b3088d8d2341ca1454531d365c15fe9c1c589)
1 /*	$NetBSD: stdio.c,v 1.16 2009/10/25 20:44:13 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
38 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: stdio.c,v 1.16 2009/10/25 20:44:13 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  */
59 int
60 __sread(cookie, buf, n)
61 	void *cookie;
62 	char *buf;
63 	int n;
64 {
65 	FILE *fp = cookie;
66 	int ret;
67 
68 	_DIAGASSERT(fp != NULL);
69 	_DIAGASSERT(buf != NULL);
70 
71 	ret = read(__sfileno(fp), buf, (size_t)n);
72 	/* if the read succeeded, update the current offset */
73 	if (ret >= 0)
74 		fp->_offset += ret;
75 	else
76 		fp->_flags &= ~__SOFF;	/* paranoia */
77 	return (ret);
78 }
79 
80 int
81 __swrite(cookie, buf, n)
82 	void *cookie;
83 	char const *buf;
84 	int n;
85 {
86 	FILE *fp = cookie;
87 
88 	_DIAGASSERT(cookie != NULL);
89 	_DIAGASSERT(buf != NULL);
90 
91 	if (fp->_flags & __SAPP)
92 		(void) lseek(__sfileno(fp), (off_t)0, SEEK_END);
93 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
94 	return write(__sfileno(fp), buf, (size_t)n);
95 }
96 
97 fpos_t
98 __sseek(cookie, offset, whence)
99 	void *cookie;
100 	fpos_t offset;
101 	int whence;
102 {
103 	FILE *fp = cookie;
104 	off_t ret;
105 
106 	_DIAGASSERT(fp != NULL);
107 
108 	ret = lseek(__sfileno(fp), (off_t)offset, whence);
109 	if (ret == -1L)
110 		fp->_flags &= ~__SOFF;
111 	else {
112 		fp->_flags |= __SOFF;
113 		fp->_offset = ret;
114 	}
115 	return (ret);
116 }
117 
118 int
119 __sclose(cookie)
120 	void *cookie;
121 {
122 
123 	_DIAGASSERT(cookie != NULL);
124 
125 	return close(__sfileno((FILE *)cookie));
126 }
127