(M68*:*:R3V[567]*:*): Use uppercase 'M'.
[glibc.git] / libio / iosetvbuf.c
blob0bd6025128a0cdcc2bb99900c0fd41e1291bdca5
1 /*
2 Copyright (C) 1993, 1996 Free Software Foundation, Inc.
4 This file is part of the GNU IO Library. This library is free
5 software; you can redistribute it and/or modify it under the
6 terms of the GNU General Public License as published by the
7 Free Software Foundation; either version 2, or (at your option)
8 any later version.
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this library; see the file COPYING. If not, write to the Free
17 Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 As a special exception, if you link this library with files
20 compiled with a GNU compiler to produce an executable, this does not cause
21 the resulting executable to be covered by the GNU General Public License.
22 This exception does not however invalidate any other reasons why
23 the executable file might be covered by the GNU General Public License. */
25 #include "libioP.h"
27 #define _IOFBF 0 /* Fully buffered. */
28 #define _IOLBF 1 /* Line buffered. */
29 #define _IONBF 2 /* No buffering. */
31 int
32 _IO_setvbuf (fp, buf, mode, size)
33 _IO_FILE* fp;
34 char* buf;
35 int mode;
36 _IO_size_t size;
38 int result;
39 CHECK_FILE (fp, EOF);
40 _IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp);
41 _IO_flockfile (fp);
42 switch (mode)
44 case _IOFBF:
45 fp->_IO_file_flags &= ~_IO_LINE_BUF|_IO_UNBUFFERED;
46 if (buf == NULL)
48 if (fp->_IO_buf_base == NULL)
50 /* There is no flag to distinguish between "fully buffered
51 mode has been explicitly set" as opposed to "line
52 buffering has not been explicitly set". In both
53 cases, _IO_LINE_BUF is off. If this is a tty, and
54 _IO_filedoalloc later gets called, it cannot know if
55 it should set the _IO_LINE_BUF flag (because that is
56 the default), or not (because we have explicitly asked
57 for fully buffered mode). So we make sure a buffer
58 gets allocated now, and explicitly turn off line
59 buffering.
61 A possibly cleaner alternative would be to add an
62 extra flag, but then flags are a finite resource. */
63 if (_IO_DOALLOCATE (fp) < 0)
65 result = EOF;
66 goto unlock_return;
68 fp->_IO_file_flags &= ~_IO_LINE_BUF;
70 result = 0;
71 goto unlock_return;
73 break;
74 case _IOLBF:
75 fp->_IO_file_flags &= ~_IO_UNBUFFERED;
76 fp->_IO_file_flags |= _IO_LINE_BUF;
77 if (buf == NULL)
79 result = 0;
80 goto unlock_return;
82 break;
83 case _IONBF:
84 buf = NULL;
85 size = 0;
86 break;
87 default:
88 result = EOF;
89 goto unlock_return;
91 result = _IO_SETBUF (fp, buf, size) == NULL ? EOF : 0;
92 unlock_return:
93 _IO_cleanup_region_end (1);
94 return result;
97 weak_alias (_IO_setvbuf, setvbuf)