HAMMER 60F/Many: Mirroring
[dragonfly.git] / lib / libc / stdio / fpurge.c
blob54e3333f5e1772396b1aa08639570c45013fa0ab
1 /*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
36 * @(#)fpurge.c 8.1 (Berkeley) 6/4/93
37 * $FreeBSD: src/lib/libc/stdio/fpurge.c,v 1.7 1999/08/28 00:01:02 peter Exp $
38 * $DragonFly: src/lib/libc/stdio/fpurge.c,v 1.6 2005/07/23 20:23:06 joerg Exp $
41 #include "namespace.h"
42 #include <errno.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include "un-namespace.h"
47 #include "local.h"
48 #include "libc_private.h"
49 #include "priv_stdio.h"
52 * fpurge: like fflush, but without writing anything: leave the
53 * given FILE's buffer empty.
55 int
56 fpurge(FILE *fp)
58 int retval;
59 FLOCKFILE(fp);
60 if (!fp->pub._flags) {
61 errno = EBADF;
62 retval = EOF;
63 } else {
64 if (HASUB(fp))
65 FREEUB(fp);
66 fp->pub._p = fp->_bf._base;
67 fp->pub._r = 0;
68 fp->pub._w = fp->pub._flags & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
69 retval = 0;
71 FUNLOCKFILE(fp);
72 return (retval);