1 /*
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * and/or other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Berkeley. The name of the
11 * University may not be used to endorse or promote products derived
12 * from this software without specific prior written permission.
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16 */
17
18 /*
19 FUNCTION
20 <<setbuf>>---specify full buffering for a file or stream
21
22 INDEX
23 setbuf
24
25 SYNOPSIS
26 #include <stdio.h>
27 void setbuf(FILE *<[fp]>, char *<[buf]>);
28
29 DESCRIPTION
30 <<setbuf>> specifies that output to the file or stream identified by <[fp]>
31 should be fully buffered. All output for this file will go to a
32 buffer (of size <<BUFSIZ>>, specified in `<<stdio.h>>'). Output will
33 be passed on to the host system only when the buffer is full, or when
34 an input operation intervenes.
35
36 You may, if you wish, supply your own buffer by passing a pointer to
37 it as the argument <[buf]>. It must have size <<BUFSIZ>>. You can
38 also use <<NULL>> as the value of <[buf]>, to signal that the
39 <<setbuf>> function is to allocate the buffer.
40
41 WARNINGS
42 You may only use <<setbuf>> before performing any file operation other
43 than opening the file.
44
45 If you supply a non-null <[buf]>, you must ensure that the associated
46 storage continues to be available until you close the stream
47 identified by <[fp]>.
48
49 RETURNS
50 <<setbuf>> does not return a result.
51
52 PORTABILITY
53 Both ANSI C and the System V Interface Definition (Issue 2) require
54 <<setbuf>>. However, they differ on the meaning of a <<NULL>> buffer
55 pointer: the SVID issue 2 specification says that a <<NULL>> buffer
56 pointer requests unbuffered output. For maximum portability, avoid
57 <<NULL>> buffer pointers.
58
59 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
60 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
61 */
62
63 #define _DEFAULT_SOURCE
64 #include <_ansi.h>
65 #include <stdio.h>
66 #include "local.h"
67
68 void
setbuf(FILE * __restrict fp,char * __restrict buf)69 setbuf (FILE *__restrict fp,
70 char *__restrict buf)
71 {
72 (void) setvbuf (fp, buf, buf ? _IOFBF : _IONBF, BUFSIZ);
73 }
74
