1 /* $NetBSD: stdio.c,v 1.22 2013/05/19 17:07:04 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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/cdefs.h>
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)stdio.c 8.1 (Berkeley) 6/4/93";
39 #else
40 __RCSID("$NetBSD: stdio.c,v 1.22 2013/05/19 17:07:04 christos Exp $");
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43
44 #include "namespace.h"
45
46 #include <assert.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <stdio.h>
50 #include <unistd.h>
51
52 #include "reentrant.h"
53 #include "local.h"
54
55 /*
56 * Small standard I/O/seek/close functions.
57 * These maintain the `known seek offset' for seek optimisation.
58 */
59 ssize_t
__sread(void * cookie,void * buf,size_t n)60 __sread(void *cookie, void *buf, size_t n)
61 {
62 FILE *fp = cookie;
63 ssize_t ret;
64
65 _DIAGASSERT(cookie != NULL);
66 _DIAGASSERT(cookie == fp->_cookie);
67 _DIAGASSERT(buf != NULL);
68
69 ret = read(__sfileno(fp), buf, n);
70 /* if the read succeeded, update the current offset */
71 if (ret >= 0)
72 fp->_offset += ret;
73 else
74 fp->_flags &= ~__SOFF; /* paranoia */
75
76 return ret;
77 }
78
79 ssize_t
__swrite(void * cookie,const void * buf,size_t n)80 __swrite(void *cookie, const void *buf, size_t n)
81 {
82 FILE *fp = cookie;
83
84 _DIAGASSERT(cookie != NULL);
85 _DIAGASSERT(cookie == fp->_cookie);
86 _DIAGASSERT(buf != NULL);
87
88 if (fp->_flags & __SAPP)
89 if (lseek(__sfileno(fp), (off_t)0, SEEK_END) == (off_t)-1) {
90 if (errno == ESPIPE) /* if unseekable, OK, */
91 fp->_flags &= ~__SAPP; /* all writes append. */
92 else
93 return -1;
94 }
95 fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */
96 return write(__sfileno(fp), buf, n);
97 }
98
99 off_t
__sseek(void * cookie,off_t offset,int whence)100 __sseek(void *cookie, off_t offset, int whence)
101 {
102 FILE *fp = cookie;
103 off_t ret;
104
105 _DIAGASSERT(cookie != NULL);
106 _DIAGASSERT(cookie == fp->_cookie);
107
108 ret = lseek(__sfileno(fp), offset, whence);
109 if (ret == (off_t)-1L)
110 fp->_flags &= ~__SOFF;
111 else {
112 fp->_flags |= __SOFF;
113 fp->_offset = ret;
114 }
115 return ret;
116 }
117
118 int
__sclose(void * cookie)119 __sclose(void *cookie)
120 {
121 FILE *fp = cookie;
122
123 _DIAGASSERT(cookie != NULL);
124 _DIAGASSERT(cookie == fp->_cookie);
125
126 return close(__sfileno(fp));
127 }
128