1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)setvbuf.c 8.2 (Berkeley) 11/16/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <stdio.h>
#include <stdlib.h>
#include "un-namespace.h"
#include "local.h"
#include "libc_private.h"
/*
* Set one of the three kinds of buffering, optionally including
* a buffer.
*/
int
setvbuf(FILE * __restrict fp, char * __restrict buf, int mode, size_t size)
{
int ret, flags;
size_t iosize;
int ttyflag;
/*
* Verify arguments. The `int' limit on `size' is due to this
* particular implementation. Note, buf and size are ignored
* when setting _IONBF.
*/
if (mode != _IONBF)
if ((mode != _IOFBF && mode != _IOLBF) || (int)size < 0)
return (EOF);
FLOCKFILE(fp);
/*
* Write current buffer, if any. Discard unread input (including
* ungetc data), cancel line buffering, and free old buffer if
* malloc()ed. We also clear any eof condition, as if this were
* a seek.
*/
ret = 0;
(void)__sflush(fp);
if (HASUB(fp))
FREEUB(fp);
fp->_r = fp->_lbfsize = 0;
flags = fp->_flags;
if (flags & __SMBF)
free((void *)fp->_bf._base);
flags &= ~(__SLBF | __SNBF | __SMBF | __SOPT | __SOFF | __SNPT | __SEOF);
/* If setting unbuffered mode, skip all the hard work. */
if (mode == _IONBF)
goto nbf;
/*
* Find optimal I/O size for seek optimization. This also returns
* a `tty flag' to suggest that we check isatty(fd), but we do not
* care since our caller told us how to buffer.
*/
flags |= __swhatbuf(fp, &iosize, &ttyflag);
if (size == 0) {
buf = NULL; /* force local allocation */
size = iosize;
}
/* Allocate buffer if needed. */
if (buf == NULL) {
if ((buf = malloc(size)) == NULL) {
/*
* Unable to honor user's request. We will return
* failure, but try again with file system size.
*/
ret = EOF;
if (size != iosize) {
size = iosize;
buf = malloc(size);
}
}
if (buf == NULL) {
/* No luck; switch to unbuffered I/O. */
nbf:
fp->_flags = flags | __SNBF;
fp->_w = 0;
fp->_bf._base = fp->_p = fp->_nbuf;
fp->_bf._size = 1;
FUNLOCKFILE(fp);
return (ret);
}
flags |= __SMBF;
}
/*
* Kill any seek optimization if the buffer is not the
* right size.
*
* SHOULD WE ALLOW MULTIPLES HERE (i.e., ok iff (size % iosize) == 0)?
*/
if (size != iosize)
flags |= __SNPT;
/*
* Fix up the FILE fields, and set __cleanup for output flush on
* exit (since we are buffered in some way).
*/
if (mode == _IOLBF)
flags |= __SLBF;
fp->_flags = flags;
fp->_bf._base = fp->_p = (unsigned char *)buf;
fp->_bf._size = size;
/* fp->_lbfsize is still 0 */
if (flags & __SWR) {
/*
* Begin or continue writing: see __swsetup(). Note
* that __SNBF is impossible (it was handled earlier).
*/
if (flags & __SLBF) {
fp->_w = 0;
fp->_lbfsize = -fp->_bf._size;
} else
fp->_w = size;
} else {
/* begin/continue reading, or stay in intermediate state */
fp->_w = 0;
}
__cleanup = _cleanup;
FUNLOCKFILE(fp);
return (ret);
}
|
