xref: /netbsd-src/lib/libc/stdio/stdio.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: stdio.c,v 1.6 1997/07/13 20:15:30 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 1.6 1997/07/13 20:15:30 christos Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47 
48 #include <fcntl.h>
49 #include <unistd.h>
50 #include <stdio.h>
51 #include "local.h"
52 
53 /*
54  * Small standard I/O/seek/close functions.
55  * These maintain the `known seek offset' for seek optimisation.
56  */
57 int
58 __sread(cookie, buf, n)
59 	void *cookie;
60 	char *buf;
61 	int n;
62 {
63 	register FILE *fp = cookie;
64 	register int ret;
65 
66 	ret = read(fp->_file, buf, n);
67 	/* if the read succeeded, update the current offset */
68 	if (ret >= 0)
69 		fp->_offset += ret;
70 	else
71 		fp->_flags &= ~__SOFF;	/* paranoia */
72 	return (ret);
73 }
74 
75 int
76 __swrite(cookie, buf, n)
77 	void *cookie;
78 	char const *buf;
79 	int n;
80 {
81 	register FILE *fp = cookie;
82 
83 	if (fp->_flags & __SAPP)
84 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
85 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
86 	return (write(fp->_file, buf, n));
87 }
88 
89 fpos_t
90 __sseek(cookie, offset, whence)
91 	void *cookie;
92 	fpos_t offset;
93 	int whence;
94 {
95 	register FILE *fp = cookie;
96 	register off_t ret;
97 
98 	ret = lseek(fp->_file, (off_t)offset, whence);
99 	if (ret == -1L)
100 		fp->_flags &= ~__SOFF;
101 	else {
102 		fp->_flags |= __SOFF;
103 		fp->_offset = ret;
104 	}
105 	return (ret);
106 }
107 
108 int
109 __sclose(cookie)
110 	void *cookie;
111 {
112 
113 	return (close(((FILE *)cookie)->_file));
114 }
115