NetBSD/lib/libc/stdio/fpurge.c

79 lines
2.7 KiB
C
Raw Normal View History

/* $NetBSD: fpurge.c,v 1.10 2000/01/21 19:53:03 mycroft Exp $ */
1993-03-21 12:45:37 +03:00
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
1993-03-21 12:45:37 +03:00
*
* 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.
*/
#include <sys/cdefs.h>
1993-03-21 12:45:37 +03:00
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)fpurge.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: fpurge.c,v 1.10 2000/01/21 19:53:03 mycroft Exp $");
#endif
1993-03-21 12:45:37 +03:00
#endif /* LIBC_SCCS and not lint */
#include <assert.h>
1993-03-21 12:45:37 +03:00
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include "local.h"
#include "reentrant.h"
1993-03-21 12:45:37 +03:00
/*
* fpurge: like fflush, but without writing anything: leave the
* given FILE's buffer empty.
*/
int
fpurge(fp)
1998-02-03 21:38:12 +03:00
FILE *fp;
1993-03-21 12:45:37 +03:00
{
_DIAGASSERT(fp != NULL);
if (fp->_flags == 0) {
1993-03-21 12:45:37 +03:00
errno = EBADF;
return (EOF);
1993-03-21 12:45:37 +03:00
}
FLOCKFILE(fp);
1993-03-21 12:45:37 +03:00
if (HASUB(fp))
FREEUB(fp);
fp->_p = fp->_bf._base;
fp->_r = 0;
fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
FUNLOCKFILE(fp);
1993-03-21 12:45:37 +03:00
return (0);
}