sl@0: /* SETBUF.C
sl@0:  * 
sl@0:  * Portions Copyright (c) 1990-1999 Nokia Corporation and/or its subsidiary(-ies).
sl@0:  * All rights reserved.
sl@0:  */
sl@0: 
sl@0: /*
sl@0:  * Copyright (c) 1990 The Regents of the University of California.
sl@0:  * All rights reserved.
sl@0:  *
sl@0:  * Redistribution and use in source and binary forms are permitted
sl@0:  * provided that the above copyright notice and this paragraph are
sl@0:  * duplicated in all such forms and that any documentation,
sl@0:  * advertising materials, and other materials related to such
sl@0:  * distribution and use acknowledge that the software was developed
sl@0:  * by the University of California, Berkeley.  The name of the
sl@0:  * University may not be used to endorse or promote products derived
sl@0:  * from this software without specific prior written permission.
sl@0:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
sl@0:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
sl@0:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
sl@0:  */
sl@0: 
sl@0: /*
sl@0: FUNCTION
sl@0: <<setbuf>>---specify full buffering for a file or stream
sl@0: 
sl@0: INDEX
sl@0: 	setbuf
sl@0: 
sl@0: ANSI_SYNOPSIS
sl@0: 	#include <stdio.h>
sl@0: 	void setbuf(FILE *<[fp]>, char *<[buf]>);
sl@0: 
sl@0: TRAD_SYNOPSIS
sl@0: 	#include <stdio.h>
sl@0: 	void setbuf(<[fp]>, <[buf]>)
sl@0: 	FILE *<[fp]>;
sl@0: 	char *<[buf]>;
sl@0: 
sl@0: DESCRIPTION
sl@0: <<setbuf>> specifies that output to the file or stream identified by <[fp]>
sl@0: should be fully buffered.  All output for this file will go to a
sl@0: buffer (of size <<BUFSIZ>>, specified in `<<stdio.h>>').  Output will
sl@0: be passed on to the host system only when the buffer is full, or when
sl@0: an input operation intervenes.
sl@0: 
sl@0: You may, if you wish, supply your own buffer by passing a pointer to
sl@0: it as the argument <[buf]>.  It must have size <<BUFSIZ>>.  You can
sl@0: also use <<NULL>> as the value of <[buf]>, to signal that the
sl@0: <<setbuf>> function is to allocate the buffer.
sl@0: 
sl@0: WARNINGS
sl@0: You may only use <<setbuf>> before performing any file operation other
sl@0: than opening the file.
sl@0: 
sl@0: If you supply a non-null <[buf]>, you must ensure that the associated
sl@0: storage continues to be available until you close the stream
sl@0: identified by <[fp]>.
sl@0: 
sl@0: RETURNS
sl@0: <<setbuf>> does not return a result.
sl@0: 
sl@0: PORTABILITY
sl@0: Both ANSI C and the System V Interface Definition (Issue 2) require
sl@0: <<setbuf>>.  However, they differ on the meaning of a <<NULL>> buffer
sl@0: pointer: the SVID issue 2 specification says that a <<NULL>> buffer
sl@0: pointer requests unbuffered output.  For maximum portability, avoid
sl@0: <<NULL>> buffer pointers.
sl@0: 
sl@0: Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
sl@0: <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
sl@0: */
sl@0: 
sl@0: #include <stdio.h>
sl@0: #include "LOCAL.H"
sl@0: 
sl@0: /**
sl@0: Change stream buffering.
sl@0: Changes the buffer used for I/O operations with the specified stream, or,
sl@0: if the specified buffer is NULL it disables buffering with the stream.
sl@0: This function should be called once the file associated with the stream 
sl@0: has been opened but before any input or output operation has been done.
sl@0: With buffered streams writing operations do not write directly 
sl@0: to the device associated with them; the data is accumulated in the buffer 
sl@0: and written to the device as a block.
sl@0: All buffers are also flushed when program terminates.
sl@0: @param fp pointer to an open file.
sl@0: @param buf User allocated buffer. Must have a length of BUFSIZ bytes.
sl@0: */
sl@0: EXPORT_C void setbuf (FILE * fp, char *buf)
sl@0: {
sl@0:   (void) setvbuf (fp, buf, buf ? _IOFBF : _IONBF, BUFSIZ);
sl@0: }