xref: /freebsd/lib/libc/stdio/stdio.c (revision 41466b50c1d5bfd1cf6adaae547a579a75d7c04e)
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 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
40 #endif
41 static const char rcsid[] =
42   "$FreeBSD$";
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include "namespace.h"
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <limits.h>
49 #include <stdio.h>
50 #include <unistd.h>
51 #include "un-namespace.h"
52 #include "local.h"
53 
54 /*
55  * Small standard I/O/seek/close functions.
56  */
57 int
58 __sread(cookie, buf, n)
59 	void *cookie;
60 	char *buf;
61 	int n;
62 {
63 	register FILE *fp = cookie;
64 
65 	return(_read(fp->_file, buf, (size_t)n));
66 }
67 
68 int
69 __swrite(cookie, buf, n)
70 	void *cookie;
71 	char const *buf;
72 	int n;
73 {
74 	register FILE *fp = cookie;
75 
76 	return (_write(fp->_file, buf, (size_t)n));
77 }
78 
79 fpos_t
80 __sseek(cookie, offset, whence)
81 	void *cookie;
82 	fpos_t offset;
83 	int whence;
84 {
85 	register FILE *fp = cookie;
86 
87 	return (lseek(fp->_file, (off_t)offset, whence));
88 }
89 
90 int
91 __sclose(cookie)
92 	void *cookie;
93 {
94 
95 	return (_close(((FILE *)cookie)->_file));
96 }
97 
98 /*
99  * Higher level wrappers.
100  */
101 int
102 _sread(fp, buf, n)
103 	FILE *fp;
104 	char *buf;
105 	int n;
106 {
107 	int ret;
108 
109 	ret = (*fp->_read)(fp->_cookie, buf, n);
110 	if (ret > 0) {
111 		if (fp->_flags & __SOFF) {
112 			if (fp->_offset <= OFF_MAX - ret)
113 				fp->_offset += ret;
114 			else
115 				fp->_flags &= ~__SOFF;
116 		}
117 	} else if (ret < 0)
118 		fp->_flags &= ~__SOFF;
119 	return (ret);
120 }
121 
122 int
123 _swrite(fp, buf, n)
124 	FILE *fp;
125 	char const *buf;
126 	int n;
127 {
128 	int ret;
129 	int serrno;
130 
131 	if (fp->_flags & __SAPP) {
132 		serrno = errno;
133 		if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
134 		    (fp->_flags & __SOPT))
135 			return (-1);
136 		errno = serrno;
137 	}
138 	ret = (*fp->_write)(fp->_cookie, buf, n);
139 	/* __SOFF removed even on success in case O_APPEND mode is set. */
140 	if (ret >= 0) {
141 		if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
142 		    fp->_offset <= OFF_MAX - ret)
143 			fp->_offset += ret;
144 		else
145 			fp->_flags &= ~__SOFF;
146 
147 	} else if (ret < 0)
148 		fp->_flags &= ~__SOFF;
149 	return (ret);
150 }
151 
152 fpos_t
153 _sseek(fp, offset, whence)
154 	FILE *fp;
155 	fpos_t offset;
156 	int whence;
157 {
158 	fpos_t ret;
159 	int serrno, errret;
160 
161 	serrno = errno;
162 	errno = 0;
163 	ret = (*fp->_seek)(fp->_cookie, offset, whence);
164 	errret = errno;
165 	if (errno == 0)
166 		errno = serrno;
167 	/*
168 	 * Disallow negative seeks per POSIX.
169 	 * It is needed here to help upper level caller
170 	 * in the cases it can't detect.
171 	 */
172 	if (ret < 0) {
173 		if (errret == 0) {
174 			if (offset != 0 || whence != SEEK_CUR) {
175 				if (HASUB(fp))
176 					FREEUB(fp);
177 				fp->_p = fp->_bf._base;
178 				fp->_r = 0;
179 				fp->_flags &= ~__SEOF;
180 			}
181 			fp->_flags |= __SERR;
182 			errno = EINVAL;
183 		} else if (errret == ESPIPE)
184 			fp->_flags &= ~__SAPP;
185 		fp->_flags &= ~__SOFF;
186 		ret = -1;
187 	} else if (fp->_flags & __SOPT) {
188 		fp->_flags |= __SOFF;
189 		fp->_offset = ret;
190 	}
191 	return (ret);
192 }
193