NetBSD/lib/libc/stdio/setvbuf.c

111 lines
3.5 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)setvbuf.c 5.2 (Berkeley) 2/1/91";
#endif /* LIBC_SCCS and not lint */
#include <stdio.h>
#include <stdlib.h>
#include "local.h"
/*
* Set one of the three kinds of buffering, optionally including
* a buffer.
*/
setvbuf(fp, buf, mode, size)
register FILE *fp;
char *buf;
register int mode;
register size_t size;
{
/*
* Verify arguments. The `int' limit on `size' is due to this
* particular implementation.
*/
if ((mode != _IOFBF && mode != _IOLBF && mode != _IONBF) ||
(int)size < 0)
return (EOF);
/*
* Write current buffer, if any; drop read count, if any.
* Make sure putc() will not think fp is line buffered.
* Free old buffer if it was from malloc(). Clear line and
* non buffer flags, and clear malloc flag.
*/
(void) __sflush(fp);
fp->_r = 0;
fp->_lbfsize = 0;
if (fp->_flags & __SMBF)
free((void *)fp->_bf._base);
fp->_flags &= ~(__SLBF|__SNBF|__SMBF);
/*
* Now put back whichever flag is needed, and fix _lbfsize
* if line buffered. Ensure output flush on exit if the
* stream will be buffered at all.
*/
switch (mode) {
case _IONBF:
fp->_flags |= __SNBF;
fp->_bf._base = fp->_p = fp->_nbuf;
fp->_bf._size = 1;
break;
case _IOLBF:
fp->_flags |= __SLBF;
fp->_lbfsize = -size;
/* FALLTHROUGH */
case _IOFBF:
/* no flag */
__cleanup = _cleanup;
fp->_bf._base = fp->_p = (unsigned char *)buf;
fp->_bf._size = size;
break;
}
/*
* Patch up write count if necessary.
*/
if (fp->_flags & __SWR)
fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : size;
return (0);
}