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
|
/* Copyright (C) 1991, 1993, 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
/* Make STREAM use the buffering method given in MODE.
If MODE indicates full or line buffering, use BUF,
a buffer of SIZE bytes; if BUF is NULL, malloc a buffer. */
int
setvbuf (stream, buf, mode, size)
FILE *stream;
char *buf;
int mode;
size_t size;
{
if (!__validfp (stream))
{
__set_errno (EINVAL);
return EOF;
}
/* The ANSI standard says setvbuf can only be called before any I/O is done,
but we allow it to replace an old buffer, flushing it first. */
if (stream->__buffer != NULL)
{
(void) fflush (stream);
/* Free the old buffer if it was malloc'd. */
if (!stream->__userbuf)
free(stream->__buffer);
}
stream->__get_limit = stream->__put_limit = NULL;
stream->__bufp = stream->__buffer = NULL;
stream->__userbuf = stream->__linebuf = stream->__linebuf_active = 0;
switch (mode)
{
default:
__set_errno (EINVAL);
return EOF;
case _IONBF: /* Unbuffered. */
stream->__buffer = NULL;
stream->__bufsize = 0;
stream->__userbuf = 1;
break;
case _IOLBF: /* Line buffered. */
stream->__linebuf = 1;
case _IOFBF: /* Fully buffered. */
if (size == 0)
{
__set_errno (EINVAL);
return EOF;
}
stream->__bufsize = size;
if (buf != NULL)
stream->__userbuf = 1;
else if ((buf = (char *) malloc (size)) == NULL)
return EOF;
stream->__buffer = buf;
break;
}
stream->__bufp = stream->__buffer;
stream->__get_limit = stream->__buffer;
/* The next output operation will prime the stream for writing. */
stream->__put_limit = stream->__buffer;
return 0;
}
|
