xref: /netbsd-src/lib/libc/stdio/stdio.c (revision 1ffa7b76c40339c17a0fb2a09fac93f287cfc046)
1 /*	$NetBSD: stdio.c,v 1.12 2003/01/18 11:29:58 thorpej 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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
43 #else
44 __RCSID("$NetBSD: stdio.c,v 1.12 2003/01/18 11:29:58 thorpej Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47 
48 #include "namespace.h"
49 
50 #include <assert.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <stdio.h>
54 #include <unistd.h>
55 
56 #include "reentrant.h"
57 #include "local.h"
58 
59 /*
60  * Small standard I/O/seek/close functions.
61  * These maintain the `known seek offset' for seek optimisation.
62  */
63 int
64 __sread(cookie, buf, n)
65 	void *cookie;
66 	char *buf;
67 	int n;
68 {
69 	FILE *fp = cookie;
70 	int ret;
71 
72 	_DIAGASSERT(fp != NULL);
73 	_DIAGASSERT(buf != NULL);
74 
75 	ret = read(fp->_file, buf, (size_t)n);
76 	/* if the read succeeded, update the current offset */
77 	if (ret >= 0)
78 		fp->_offset += ret;
79 	else
80 		fp->_flags &= ~__SOFF;	/* paranoia */
81 	return (ret);
82 }
83 
84 int
85 __swrite(cookie, buf, n)
86 	void *cookie;
87 	char const *buf;
88 	int n;
89 {
90 	FILE *fp = cookie;
91 
92 	_DIAGASSERT(cookie != NULL);
93 	_DIAGASSERT(buf != NULL);
94 
95 	if (fp->_flags & __SAPP)
96 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
97 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
98 	return (write(fp->_file, buf, (size_t)n));
99 }
100 
101 fpos_t
102 __sseek(cookie, offset, whence)
103 	void *cookie;
104 	fpos_t offset;
105 	int whence;
106 {
107 	FILE *fp = cookie;
108 	off_t ret;
109 
110 	_DIAGASSERT(fp != NULL);
111 
112 	ret = lseek(fp->_file, (off_t)offset, whence);
113 	if (ret == -1L)
114 		fp->_flags &= ~__SOFF;
115 	else {
116 		fp->_flags |= __SOFF;
117 		fp->_offset = ret;
118 	}
119 	return (ret);
120 }
121 
122 int
123 __sclose(cookie)
124 	void *cookie;
125 {
126 
127 	_DIAGASSERT(cookie != NULL);
128 
129 	return (close(((FILE *)cookie)->_file));
130 }
131