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40a55d20 UD |
1 | /* Copyright (C) 1993, 1996, 1997 Free Software Foundation, Inc. |
2 | This file is part of the GNU IO Library. | |
96aa2d94 | 3 | |
40a55d20 UD |
4 | This library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU General Public License as | |
6 | published by the Free Software Foundation; either version 2, or (at | |
7 | your option) any later version. | |
96aa2d94 | 8 | |
40a55d20 UD |
9 | This library is distributed in the hope that it will be useful, but |
10 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | General Public License for more details. | |
96aa2d94 | 13 | |
40a55d20 UD |
14 | You should have received a copy of the GNU General Public License |
15 | along with this library; see the file COPYING. If not, write to | |
16 | the Free Software Foundation, 59 Temple Place - Suite 330, Boston, | |
17 | MA 02111-1307, USA. | |
96aa2d94 | 18 | |
40a55d20 UD |
19 | As a special exception, if you link this library with files |
20 | compiled with a GNU compiler to produce an executable, this does | |
21 | not cause the resulting executable to be covered by the GNU General | |
22 | Public License. This exception does not however invalidate any | |
23 | other reasons why the executable file might be covered by the GNU | |
24 | General Public License. */ | |
96aa2d94 RM |
25 | |
26 | #include "libioP.h" | |
27 | ||
28 | #define _IOFBF 0 /* Fully buffered. */ | |
29 | #define _IOLBF 1 /* Line buffered. */ | |
30 | #define _IONBF 2 /* No buffering. */ | |
31 | ||
32 | int | |
33 | _IO_setvbuf (fp, buf, mode, size) | |
40a55d20 UD |
34 | _IO_FILE *fp; |
35 | char *buf; | |
96aa2d94 RM |
36 | int mode; |
37 | _IO_size_t size; | |
38 | { | |
7c713e28 | 39 | int result; |
96aa2d94 | 40 | CHECK_FILE (fp, EOF); |
68dbb3a6 | 41 | _IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp); |
7c713e28 | 42 | _IO_flockfile (fp); |
96aa2d94 RM |
43 | switch (mode) |
44 | { | |
45 | case _IOFBF: | |
a18f587d | 46 | fp->_IO_file_flags &= ~_IO_LINE_BUF|_IO_UNBUFFERED; |
96aa2d94 RM |
47 | if (buf == NULL) |
48 | { | |
49 | if (fp->_IO_buf_base == NULL) | |
50 | { | |
51 | /* There is no flag to distinguish between "fully buffered | |
52 | mode has been explicitly set" as opposed to "line | |
53 | buffering has not been explicitly set". In both | |
54 | cases, _IO_LINE_BUF is off. If this is a tty, and | |
55 | _IO_filedoalloc later gets called, it cannot know if | |
56 | it should set the _IO_LINE_BUF flag (because that is | |
57 | the default), or not (because we have explicitly asked | |
58 | for fully buffered mode). So we make sure a buffer | |
59 | gets allocated now, and explicitly turn off line | |
60 | buffering. | |
61 | ||
62 | A possibly cleaner alternative would be to add an | |
63 | extra flag, but then flags are a finite resource. */ | |
64 | if (_IO_DOALLOCATE (fp) < 0) | |
7c713e28 RM |
65 | { |
66 | result = EOF; | |
67 | goto unlock_return; | |
68 | } | |
96aa2d94 RM |
69 | fp->_IO_file_flags &= ~_IO_LINE_BUF; |
70 | } | |
7c713e28 RM |
71 | result = 0; |
72 | goto unlock_return; | |
96aa2d94 RM |
73 | } |
74 | break; | |
75 | case _IOLBF: | |
a18f587d | 76 | fp->_IO_file_flags &= ~_IO_UNBUFFERED; |
96aa2d94 RM |
77 | fp->_IO_file_flags |= _IO_LINE_BUF; |
78 | if (buf == NULL) | |
7c713e28 RM |
79 | { |
80 | result = 0; | |
81 | goto unlock_return; | |
82 | } | |
96aa2d94 RM |
83 | break; |
84 | case _IONBF: | |
85 | buf = NULL; | |
86 | size = 0; | |
87 | break; | |
88 | default: | |
7c713e28 RM |
89 | result = EOF; |
90 | goto unlock_return; | |
96aa2d94 | 91 | } |
7c713e28 RM |
92 | result = _IO_SETBUF (fp, buf, size) == NULL ? EOF : 0; |
93 | unlock_return: | |
68dbb3a6 | 94 | _IO_cleanup_region_end (1); |
7c713e28 | 95 | return result; |
96aa2d94 | 96 | } |
d3b7d2ac | 97 | |
ca34d7a7 | 98 | #ifdef weak_alias |
d3b7d2ac | 99 | weak_alias (_IO_setvbuf, setvbuf) |
ca34d7a7 | 100 | #endif |