3 * Portions Copyright (c) 1990-1999 Nokia Corporation and/or its subsidiary(-ies).
8 * Copyright (c) 1990 The Regents of the University of California.
11 * Redistribution and use in source and binary forms are permitted
12 * provided that the above copyright notice and this paragraph are
13 * duplicated in all such forms and that any documentation,
14 * advertising materials, and other materials related to such
15 * distribution and use acknowledge that the software was developed
16 * by the University of California, Berkeley. The name of the
17 * University may not be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
26 <<setbuf>>---specify full buffering for a file or stream
33 void setbuf(FILE *<[fp]>, char *<[buf]>);
37 void setbuf(<[fp]>, <[buf]>)
42 <<setbuf>> specifies that output to the file or stream identified by <[fp]>
43 should be fully buffered. All output for this file will go to a
44 buffer (of size <<BUFSIZ>>, specified in `<<stdio.h>>'). Output will
45 be passed on to the host system only when the buffer is full, or when
46 an input operation intervenes.
48 You may, if you wish, supply your own buffer by passing a pointer to
49 it as the argument <[buf]>. It must have size <<BUFSIZ>>. You can
50 also use <<NULL>> as the value of <[buf]>, to signal that the
51 <<setbuf>> function is to allocate the buffer.
54 You may only use <<setbuf>> before performing any file operation other
55 than opening the file.
57 If you supply a non-null <[buf]>, you must ensure that the associated
58 storage continues to be available until you close the stream
62 <<setbuf>> does not return a result.
65 Both ANSI C and the System V Interface Definition (Issue 2) require
66 <<setbuf>>. However, they differ on the meaning of a <<NULL>> buffer
67 pointer: the SVID issue 2 specification says that a <<NULL>> buffer
68 pointer requests unbuffered output. For maximum portability, avoid
69 <<NULL>> buffer pointers.
71 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
72 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
79 Change stream buffering.
80 Changes the buffer used for I/O operations with the specified stream, or,
81 if the specified buffer is NULL it disables buffering with the stream.
82 This function should be called once the file associated with the stream
83 has been opened but before any input or output operation has been done.
84 With buffered streams writing operations do not write directly
85 to the device associated with them; the data is accumulated in the buffer
86 and written to the device as a block.
87 All buffers are also flushed when program terminates.
88 @param fp pointer to an open file.
89 @param buf User allocated buffer. Must have a length of BUFSIZ bytes.
91 EXPORT_C void setbuf (FILE * fp, char *buf)
93 (void) setvbuf (fp, buf, buf ? _IOFBF : _IONBF, BUFSIZ);