xref: /freebsd/lib/libc/stdio/stdio.c (revision 5cd19a3cfd1ca09f228df51c1e50d31a9a11c65d)
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 static char sccsid[] = "@(#)stdio.c	8.1 (Berkeley) 6/4/93";
39 #endif /* LIBC_SCCS and not lint */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include "namespace.h"
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <limits.h>
47 #include <stdio.h>
48 #include <unistd.h>
49 #include "un-namespace.h"
50 #include "local.h"
51 
52 /*
53  * Small standard I/O/seek/close functions.
54  */
55 int
56 __sread(cookie, buf, n)
57 	void *cookie;
58 	char *buf;
59 	int n;
60 {
61 	FILE *fp = cookie;
62 
63 	return(_read(fp->_file, buf, (size_t)n));
64 }
65 
66 int
67 __swrite(cookie, buf, n)
68 	void *cookie;
69 	char const *buf;
70 	int n;
71 {
72 	FILE *fp = cookie;
73 
74 	return (_write(fp->_file, buf, (size_t)n));
75 }
76 
77 fpos_t
78 __sseek(cookie, offset, whence)
79 	void *cookie;
80 	fpos_t offset;
81 	int whence;
82 {
83 	FILE *fp = cookie;
84 
85 	return (lseek(fp->_file, (off_t)offset, whence));
86 }
87 
88 int
89 __sclose(cookie)
90 	void *cookie;
91 {
92 
93 	return (_close(((FILE *)cookie)->_file));
94 }
95 
96 /*
97  * Higher level wrappers.
98  */
99 int
100 _sread(fp, buf, n)
101 	FILE *fp;
102 	char *buf;
103 	int n;
104 {
105 	int ret;
106 
107 	ret = (*fp->_read)(fp->_cookie, buf, n);
108 	if (ret > 0) {
109 		if (fp->_flags & __SOFF) {
110 			if (fp->_offset <= OFF_MAX - ret)
111 				fp->_offset += ret;
112 			else
113 				fp->_flags &= ~__SOFF;
114 		}
115 	} else if (ret < 0)
116 		fp->_flags &= ~__SOFF;
117 	return (ret);
118 }
119 
120 int
121 _swrite(fp, buf, n)
122 	FILE *fp;
123 	char const *buf;
124 	int n;
125 {
126 	int ret;
127 	int serrno;
128 
129 	if (fp->_flags & __SAPP) {
130 		serrno = errno;
131 		if (_sseek(fp, (fpos_t)0, SEEK_END) == -1 &&
132 		    (fp->_flags & __SOPT))
133 			return (-1);
134 		errno = serrno;
135 	}
136 	ret = (*fp->_write)(fp->_cookie, buf, n);
137 	/* __SOFF removed even on success in case O_APPEND mode is set. */
138 	if (ret >= 0) {
139 		if ((fp->_flags & (__SAPP|__SOFF)) == (__SAPP|__SOFF) &&
140 		    fp->_offset <= OFF_MAX - ret)
141 			fp->_offset += ret;
142 		else
143 			fp->_flags &= ~__SOFF;
144 
145 	} else if (ret < 0)
146 		fp->_flags &= ~__SOFF;
147 	return (ret);
148 }
149 
150 fpos_t
151 _sseek(fp, offset, whence)
152 	FILE *fp;
153 	fpos_t offset;
154 	int whence;
155 {
156 	fpos_t ret;
157 	int serrno, errret;
158 
159 	serrno = errno;
160 	errno = 0;
161 	ret = (*fp->_seek)(fp->_cookie, offset, whence);
162 	errret = errno;
163 	if (errno == 0)
164 		errno = serrno;
165 	/*
166 	 * Disallow negative seeks per POSIX.
167 	 * It is needed here to help upper level caller
168 	 * in the cases it can't detect.
169 	 */
170 	if (ret < 0) {
171 		if (errret == 0) {
172 			if (offset != 0 || whence != SEEK_CUR) {
173 				if (HASUB(fp))
174 					FREEUB(fp);
175 				fp->_p = fp->_bf._base;
176 				fp->_r = 0;
177 				fp->_flags &= ~__SEOF;
178 			}
179 			fp->_flags |= __SERR;
180 			errno = EINVAL;
181 		} else if (errret == ESPIPE)
182 			fp->_flags &= ~__SAPP;
183 		fp->_flags &= ~__SOFF;
184 		ret = -1;
185 	} else if (fp->_flags & __SOPT) {
186 		fp->_flags |= __SOFF;
187 		fp->_offset = ret;
188 	}
189 	return (ret);
190 }
191