xref: /netbsd-src/lib/libc/stdio/stdio.c (revision e7f7fdba9a2ceba2e63bb84ca8a38c2624b7bf1c)
1 /*	$NetBSD: stdio.c,v 1.9 1998/11/15 17:19:53 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. 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 1.9 1998/11/15 17:19:53 christos Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47 
48 #include "namespace.h"
49 #include <fcntl.h>
50 #include <unistd.h>
51 #include <stdio.h>
52 #include "local.h"
53 
54 /*
55  * Small standard I/O/seek/close functions.
56  * These maintain the `known seek offset' for seek optimisation.
57  */
58 int
59 __sread(cookie, buf, n)
60 	void *cookie;
61 	char *buf;
62 	int n;
63 {
64 	FILE *fp = cookie;
65 	int ret;
66 
67 	ret = read(fp->_file, buf, (size_t)n);
68 	/* if the read succeeded, update the current offset */
69 	if (ret >= 0)
70 		fp->_offset += ret;
71 	else
72 		fp->_flags &= ~__SOFF;	/* paranoia */
73 	return (ret);
74 }
75 
76 int
77 __swrite(cookie, buf, n)
78 	void *cookie;
79 	char const *buf;
80 	int n;
81 {
82 	FILE *fp = cookie;
83 
84 	if (fp->_flags & __SAPP)
85 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
86 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
87 	return (write(fp->_file, buf, (size_t)n));
88 }
89 
90 fpos_t
91 __sseek(cookie, offset, whence)
92 	void *cookie;
93 	fpos_t offset;
94 	int whence;
95 {
96 	FILE *fp = cookie;
97 	off_t ret;
98 
99 	ret = lseek(fp->_file, (off_t)offset, whence);
100 	if (ret == -1L)
101 		fp->_flags &= ~__SOFF;
102 	else {
103 		fp->_flags |= __SOFF;
104 		fp->_offset = ret;
105 	}
106 	return (ret);
107 }
108 
109 int
110 __sclose(cookie)
111 	void *cookie;
112 {
113 
114 	return (close(((FILE *)cookie)->_file));
115 }
116