xref: /dragonfly/lib/libc/stdio/stdio.c (revision 19fe1c42)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  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  * @(#)stdio.c	8.1 (Berkeley) 6/4/93
37  * $FreeBSD: src/lib/libc/stdio/stdio.c,v 1.9 2000/01/27 23:06:46 jasone Exp $
38  * $DragonFly: src/lib/libc/stdio/stdio.c,v 1.7 2005/11/20 11:07:30 swildner Exp $
39  */
40 
41 #include "namespace.h"
42 #include <fcntl.h>
43 #include <unistd.h>
44 #include <stdio.h>
45 #include "un-namespace.h"
46 
47 #include "local.h"
48 #include "priv_stdio.h"
49 
50 /*
51  * Small standard I/O/seek/close functions.
52  * These maintain the `known seek offset' for seek optimisation.
53  */
54 int
55 __sread(void *cookie, char *buf, int n)
56 {
57 	FILE *fp = cookie;
58 	int ret;
59 
60 	ret = _read(fp->pub._fileno, buf, (size_t)n);
61 	/* if the read succeeded, update the current offset */
62 	if (ret >= 0)
63 		fp->_offset += ret;
64 	else
65 		fp->pub._flags &= ~__SOFF;	/* paranoia */
66 	return (ret);
67 }
68 
69 int
70 __swrite(void *cookie, char const *buf, int n)
71 {
72 	FILE *fp = cookie;
73 
74 	if (fp->pub._flags & __SAPP)
75 		lseek(fp->pub._fileno, (off_t)0, SEEK_END);
76 	fp->pub._flags &= ~__SOFF;	/* in case FAPPEND mode is set */
77 	return (_write(fp->pub._fileno, buf, (size_t)n));
78 }
79 
80 fpos_t
81 __sseek(void *cookie, fpos_t offset, int whence)
82 {
83 	FILE *fp = cookie;
84 	off_t ret;
85 
86 	ret = lseek(fp->pub._fileno, (off_t)offset, whence);
87 	if (ret == -1)
88 		fp->pub._flags &= ~__SOFF;
89 	else {
90 		fp->pub._flags |= __SOFF;
91 		fp->_offset = ret;
92 	}
93 	return (ret);
94 }
95 
96 int
97 __sclose(void *cookie)
98 {
99 
100 	return (_close(((FILE *)cookie)->pub._fileno));
101 }
102