1 /*	$OpenBSD: stdio.c,v 1.9 2005/08/08 08:05:36 espie 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 <errno.h>
35 #include <fcntl.h>
36 #include <unistd.h>
37 #include <stdio.h>
38 #include "local.h"
39 
40 /*
41  * Small standard I/O/seek/close functions.
42  * These maintain the `known seek offset' for seek optimisation.
43  */
44 int
__sread(void * cookie,char * buf,int n)45 __sread(void *cookie, char *buf, int n)
46 {
47 	FILE *fp = cookie;
48 	int ret;
49 
50 	ret = TEMP_FAILURE_RETRY(read(fp->_file, buf, n));
51 	/* if the read succeeded, update the current offset */
52 	if (ret >= 0)
53 		fp->_offset += ret;
54 	else
55 		fp->_flags &= ~__SOFF;	/* paranoia */
56 	return (ret);
57 }
58 
59 int
__swrite(void * cookie,const char * buf,int n)60 __swrite(void *cookie, const char *buf, int n)
61 {
62 	FILE *fp = cookie;
63 
64 	if (fp->_flags & __SAPP)
65 		(void) TEMP_FAILURE_RETRY(lseek(fp->_file, (off_t)0, SEEK_END));
66 	fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */
67 	return TEMP_FAILURE_RETRY(write(fp->_file, buf, n));
68 }
69 
70 fpos_t
__sseek(void * cookie,fpos_t offset,int whence)71 __sseek(void *cookie, fpos_t offset, int whence)
72 {
73 	FILE *fp = cookie;
74 	off_t ret;
75 
76 	ret = TEMP_FAILURE_RETRY(lseek(fp->_file, (off_t)offset, whence));
77 	if (ret == (off_t)-1)
78 		fp->_flags &= ~__SOFF;
79 	else {
80 		fp->_flags |= __SOFF;
81 		fp->_offset = ret;
82 	}
83 	return (ret);
84 }
85 
86 int
__sclose(void * cookie)87 __sclose(void *cookie)
88 {
89 	return close(((FILE *)cookie)->_file);
90 }
91