xref: /netbsd-src/lib/libc/stdio/stdio.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: stdio.c,v 1.5 1996/03/29 23:29:25 jtc 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 #if defined(LIBC_SCCS) && !defined(lint)
40 #if 0
41 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
42 #endif
43 static char rcsid[] = "$NetBSD: stdio.c,v 1.5 1996/03/29 23:29:25 jtc Exp $";
44 #endif /* LIBC_SCCS and not lint */
45 
46 #include <fcntl.h>
47 #include <unistd.h>
48 #include <stdio.h>
49 #include "local.h"
50 
51 /*
52  * Small standard I/O/seek/close functions.
53  * These maintain the `known seek offset' for seek optimisation.
54  */
55 int
56 __sread(cookie, buf, n)
57 	void *cookie;
58 	char *buf;
59 	int n;
60 {
61 	register FILE *fp = cookie;
62 	register int ret;
63 
64 	ret = read(fp->_file, buf, n);
65 	/* if the read succeeded, update the current offset */
66 	if (ret >= 0)
67 		fp->_offset += ret;
68 	else
69 		fp->_flags &= ~__SOFF;	/* paranoia */
70 	return (ret);
71 }
72 
73 int
74 __swrite(cookie, buf, n)
75 	void *cookie;
76 	char const *buf;
77 	int n;
78 {
79 	register FILE *fp = cookie;
80 
81 	if (fp->_flags & __SAPP)
82 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
83 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
84 	return (write(fp->_file, buf, n));
85 }
86 
87 fpos_t
88 __sseek(cookie, offset, whence)
89 	void *cookie;
90 	fpos_t offset;
91 	int whence;
92 {
93 	register FILE *fp = cookie;
94 	register off_t ret;
95 
96 	ret = lseek(fp->_file, (off_t)offset, whence);
97 	if (ret == -1L)
98 		fp->_flags &= ~__SOFF;
99 	else {
100 		fp->_flags |= __SOFF;
101 		fp->_offset = ret;
102 	}
103 	return (ret);
104 }
105 
106 int
107 __sclose(cookie)
108 	void *cookie;
109 {
110 
111 	return (close(((FILE *)cookie)->_file));
112 }
113