1 /* $OpenBSD: stdio.c,v 1.10 2016/09/21 04:38:56 guenther Exp $ */
2 /*-
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Chris Torek.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <stdio.h>
35 #include <unistd.h>
36 #include "local.h"
37
38 /*
39 * Small standard I/O/seek/close functions.
40 * These maintain the `known seek offset' for seek optimisation.
41 */
42 int
__sread(void * cookie,char * buf,int n)43 __sread(void *cookie, char *buf, int n)
44 {
45 FILE *fp = cookie;
46 int ret;
47
48 ret = read(fp->_file, buf, n);
49 /* if the read succeeded, update the current offset */
50 if (ret >= 0)
51 fp->_offset += ret;
52 else
53 fp->_flags &= ~__SOFF; /* paranoia */
54 return (ret);
55 }
56
57 int
__swrite(void * cookie,const char * buf,int n)58 __swrite(void *cookie, const char *buf, int n)
59 {
60 FILE *fp = cookie;
61
62 if (fp->_flags & __SAPP)
63 (void) lseek(fp->_file, 0, SEEK_END);
64 fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */
65 return (write(fp->_file, buf, n));
66 }
67
68 fpos_t
__sseek(void * cookie,fpos_t offset,int whence)69 __sseek(void *cookie, fpos_t offset, int whence)
70 {
71 FILE *fp = cookie;
72 off_t ret;
73
74 ret = lseek(fp->_file, offset, whence);
75 if (ret == -1)
76 fp->_flags &= ~__SOFF;
77 else {
78 fp->_flags |= __SOFF;
79 fp->_offset = ret;
80 }
81 return (ret);
82 }
83
84 int
__sclose(void * cookie)85 __sclose(void *cookie)
86 {
87 return (close(((FILE *)cookie)->_file));
88 }
89