/*
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/*
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* Copyright (c) 1990 The Regents of the University of California.
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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* All rights reserved.
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*
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*
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* Redistribution and use in source and binary forms are permitted
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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*/
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/*
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/*
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FUNCTION
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FUNCTION
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<<setvbuf>>---specify file or stream buffering
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<<setvbuf>>---specify file or stream buffering
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INDEX
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INDEX
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setvbuf
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setvbuf
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ANSI_SYNOPSIS
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ANSI_SYNOPSIS
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#include <stdio.h>
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#include <stdio.h>
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int setvbuf(FILE *<[fp]>, char *<[buf]>,
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int setvbuf(FILE *<[fp]>, char *<[buf]>,
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int <[mode]>, size_t <[size]>);
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int <[mode]>, size_t <[size]>);
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TRAD_SYNOPSIS
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TRAD_SYNOPSIS
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#include <stdio.h>
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#include <stdio.h>
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int setvbuf(<[fp]>, <[buf]>, <[mode]>, <[size]>)
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int setvbuf(<[fp]>, <[buf]>, <[mode]>, <[size]>)
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FILE *<[fp]>;
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FILE *<[fp]>;
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char *<[buf]>;
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char *<[buf]>;
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int <[mode]>;
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int <[mode]>;
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size_t <[size]>;
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size_t <[size]>;
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DESCRIPTION
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DESCRIPTION
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Use <<setvbuf>> to specify what kind of buffering you want for the
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Use <<setvbuf>> to specify what kind of buffering you want for the
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file or stream identified by <[fp]>, by using one of the following
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file or stream identified by <[fp]>, by using one of the following
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values (from <<stdio.h>>) as the <[mode]> argument:
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values (from <<stdio.h>>) as the <[mode]> argument:
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o+
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o+
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o _IONBF
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o _IONBF
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Do not use a buffer: send output directly to the host system for the
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Do not use a buffer: send output directly to the host system for the
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file or stream identified by <[fp]>.
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file or stream identified by <[fp]>.
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o _IOFBF
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o _IOFBF
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Use full output buffering: output will be passed on to the host system
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Use full output buffering: output will be passed on to the host system
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only when the buffer is full, or when an input operation intervenes.
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only when the buffer is full, or when an input operation intervenes.
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o _IOLBF
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o _IOLBF
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Use line buffering: pass on output to the host system at every
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Use line buffering: pass on output to the host system at every
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newline, as well as when the buffer is full, or when an input
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newline, as well as when the buffer is full, or when an input
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operation intervenes.
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operation intervenes.
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o-
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o-
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Use the <[size]> argument to specify how large a buffer you wish. You
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Use the <[size]> argument to specify how large a buffer you wish. You
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can supply the buffer itself, if you wish, by passing a pointer to a
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can supply the buffer itself, if you wish, by passing a pointer to a
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suitable area of memory as <[buf]>. Otherwise, you may pass <<NULL>>
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suitable area of memory as <[buf]>. Otherwise, you may pass <<NULL>>
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as the <[buf]> argument, and <<setvbuf>> will allocate the buffer.
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as the <[buf]> argument, and <<setvbuf>> will allocate the buffer.
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WARNINGS
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WARNINGS
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You may only use <<setvbuf>> before performing any file operation other
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You may only use <<setvbuf>> before performing any file operation other
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than opening the file.
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than opening the file.
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If you supply a non-null <[buf]>, you must ensure that the associated
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If you supply a non-null <[buf]>, you must ensure that the associated
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storage continues to be available until you close the stream
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storage continues to be available until you close the stream
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identified by <[fp]>.
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identified by <[fp]>.
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RETURNS
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RETURNS
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A <<0>> result indicates success, <<EOF>> failure (invalid <[mode]> or
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A <<0>> result indicates success, <<EOF>> failure (invalid <[mode]> or
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<[size]> can cause failure).
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<[size]> can cause failure).
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PORTABILITY
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PORTABILITY
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Both ANSI C and the System V Interface Definition (Issue 2) require
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Both ANSI C and the System V Interface Definition (Issue 2) require
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<<setvbuf>>. However, they differ on the meaning of a <<NULL>> buffer
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<<setvbuf>>. However, they differ on the meaning of a <<NULL>> buffer
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pointer: the SVID issue 2 specification says that a <<NULL>> buffer
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pointer: the SVID issue 2 specification says that a <<NULL>> buffer
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pointer requests unbuffered output. For maximum portability, avoid
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pointer requests unbuffered output. For maximum portability, avoid
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<<NULL>> buffer pointers.
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<<NULL>> buffer pointers.
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Both specifications describe the result on failure only as a
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Both specifications describe the result on failure only as a
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nonzero value.
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nonzero value.
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Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
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Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
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<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
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<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
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*/
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*/
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#include <_ansi.h>
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#include <_ansi.h>
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#include <stdio.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdlib.h>
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#include "local.h"
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#include "local.h"
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/*
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/*
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* Set one of the three kinds of buffering, optionally including a buffer.
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* Set one of the three kinds of buffering, optionally including a buffer.
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*/
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*/
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int
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int
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_DEFUN (setvbuf, (fp, buf, mode, size),
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_DEFUN (setvbuf, (fp, buf, mode, size),
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register FILE * fp _AND
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register FILE * fp _AND
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char *buf _AND
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char *buf _AND
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register int mode _AND
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register int mode _AND
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register size_t size)
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register size_t size)
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{
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{
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int ret = 0;
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int ret = 0;
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CHECK_INIT (fp);
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CHECK_INIT (fp);
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/*
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/*
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* Verify arguments. The `int' limit on `size' is due to this
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* Verify arguments. The `int' limit on `size' is due to this
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* particular implementation.
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* particular implementation.
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*/
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*/
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if ((mode != _IOFBF && mode != _IOLBF && mode != _IONBF) || (int)(_POINTER_INT) size < 0)
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if ((mode != _IOFBF && mode != _IOLBF && mode != _IONBF) || (int)(_POINTER_INT) size < 0)
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return (EOF);
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return (EOF);
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/*
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/*
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* Write current buffer, if any; drop read count, if any.
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* Write current buffer, if any; drop read count, if any.
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* Make sure putc() will not think fp is line buffered.
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* Make sure putc() will not think fp is line buffered.
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* Free old buffer if it was from malloc(). Clear line and
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* Free old buffer if it was from malloc(). Clear line and
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* non buffer flags, and clear malloc flag.
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* non buffer flags, and clear malloc flag.
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*/
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*/
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(void) fflush (fp);
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(void) fflush (fp);
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fp->_r = 0;
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fp->_r = 0;
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fp->_lbfsize = 0;
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fp->_lbfsize = 0;
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if (fp->_flags & __SMBF)
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if (fp->_flags & __SMBF)
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_free_r (fp->_data, (void *) fp->_bf._base);
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_free_r (fp->_data, (void *) fp->_bf._base);
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fp->_flags &= ~(__SLBF | __SNBF | __SMBF);
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fp->_flags &= ~(__SLBF | __SNBF | __SMBF);
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if (mode == _IONBF)
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if (mode == _IONBF)
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goto nbf;
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goto nbf;
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/*
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/*
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* Allocate buffer if needed. */
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* Allocate buffer if needed. */
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if (buf == NULL)
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if (buf == NULL)
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{
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{
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/* we need this here because malloc() may return a pointer
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/* we need this here because malloc() may return a pointer
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even if size == 0 */
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even if size == 0 */
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if (!size) size = BUFSIZ;
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if (!size) size = BUFSIZ;
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if ((buf = malloc (size)) == NULL)
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if ((buf = malloc (size)) == NULL)
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{
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{
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ret = EOF;
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ret = EOF;
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/* Try another size... */
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/* Try another size... */
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buf = malloc (BUFSIZ);
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buf = malloc (BUFSIZ);
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size = BUFSIZ;
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size = BUFSIZ;
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}
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}
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if (buf == NULL)
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if (buf == NULL)
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{
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{
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/* Can't allocate it, let's try another approach */
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/* Can't allocate it, let's try another approach */
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nbf:
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nbf:
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fp->_flags |= __SNBF;
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fp->_flags |= __SNBF;
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fp->_w = 0;
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fp->_w = 0;
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fp->_bf._base = fp->_p = fp->_nbuf;
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fp->_bf._base = fp->_p = fp->_nbuf;
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fp->_bf._size = 1;
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fp->_bf._size = 1;
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return (ret);
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return (ret);
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}
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}
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fp->_flags |= __SMBF;
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fp->_flags |= __SMBF;
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}
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}
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/*
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/*
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* Now put back whichever flag is needed, and fix _lbfsize
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* Now put back whichever flag is needed, and fix _lbfsize
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* if line buffered. Ensure output flush on exit if the
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* if line buffered. Ensure output flush on exit if the
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* stream will be buffered at all.
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* stream will be buffered at all.
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* If buf is NULL then make _lbfsize 0 to force the buffer
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* If buf is NULL then make _lbfsize 0 to force the buffer
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* to be flushed and hence malloced on first use
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* to be flushed and hence malloced on first use
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*/
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*/
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switch (mode)
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switch (mode)
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{
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{
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case _IOLBF:
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case _IOLBF:
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fp->_flags |= __SLBF;
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fp->_flags |= __SLBF;
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fp->_lbfsize = buf ? -size : 0;
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fp->_lbfsize = buf ? -size : 0;
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/* FALLTHROUGH */
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/* FALLTHROUGH */
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case _IOFBF:
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case _IOFBF:
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/* no flag */
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/* no flag */
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fp->_data->__cleanup = _cleanup_r;
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fp->_data->__cleanup = _cleanup_r;
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fp->_bf._base = fp->_p = (unsigned char *) buf;
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fp->_bf._base = fp->_p = (unsigned char *) buf;
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fp->_bf._size = size;
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fp->_bf._size = size;
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break;
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break;
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}
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}
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/*
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/*
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* Patch up write count if necessary.
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* Patch up write count if necessary.
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*/
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*/
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if (fp->_flags & __SWR)
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if (fp->_flags & __SWR)
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fp->_w = fp->_flags & (__SLBF | __SNBF) ? 0 : size;
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fp->_w = fp->_flags & (__SLBF | __SNBF) ? 0 : size;
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return 0;
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return 0;
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}
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}
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