xref: /netbsd-src/lib/libc/stdio/stdio.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Chris Torek.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 /*static char *sccsid = "from: @(#)stdio.c	5.3 (Berkeley) 2/24/91";*/
39 static char *rcsid = "$Id: stdio.c,v 1.3 1993/08/26 00:47:27 jtc Exp $";
40 #endif /* LIBC_SCCS and not lint */
41 
42 #include <fcntl.h>
43 #include <unistd.h>
44 #include <stdio.h>
45 #include "local.h"
46 
47 /*
48  * Small standard I/O/seek/close functions.
49  * These maintain the `known seek offset' for seek optimisation.
50  */
51 __sread(cookie, buf, n)
52 	void *cookie;
53 	char *buf;
54 	int n;
55 {
56 	register FILE *fp = cookie;
57 	register int ret;
58 
59 	ret = read(fp->_file, buf, n);
60 	/* if the read succeeded, update the current offset */
61 	if (ret >= 0)
62 		fp->_offset += ret;
63 	else
64 		fp->_flags &= ~__SOFF;	/* paranoia */
65 	return (ret);
66 }
67 
68 __swrite(cookie, buf, n)
69 	void *cookie;
70 	char const *buf;
71 	int n;
72 {
73 	register FILE *fp = cookie;
74 
75 	if (fp->_flags & __SAPP)
76 		(void) lseek(fp->_file, (off_t)0, SEEK_END);
77 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
78 	return (write(fp->_file, buf, n));
79 }
80 
81 fpos_t
82 __sseek(cookie, offset, whence)
83 	void *cookie;
84 	fpos_t offset;
85 	int whence;
86 {
87 	register FILE *fp = cookie;
88 	register off_t ret;
89 
90 	ret = lseek(fp->_file, (off_t)offset, whence);
91 	if (ret == -1L)
92 		fp->_flags &= ~__SOFF;
93 	else {
94 		fp->_flags |= __SOFF;
95 		fp->_offset = ret;
96 	}
97 	return (ret);
98 }
99 
100 __sclose(cookie)
101 	void *cookie;
102 {
103 
104 	return (close(((FILE *)cookie)->_file));
105 }
106