NetBSD/lib/libc/stdio/fflush.c

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/* $NetBSD: fflush.c,v 1.11 1998/02/03 18:41:07 perry Exp $ */
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/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
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*
* 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>
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#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93";
#else
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__RCSID("$NetBSD: fflush.c,v 1.11 1998/02/03 18:41:07 perry Exp $");
#endif
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#endif /* LIBC_SCCS and not lint */
#include <errno.h>
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#include <stdio.h>
#include "local.h"
#include "reentrant.h"
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#ifdef _REENT
extern rwlock_t __sfp_lock;
#endif
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/* Flush a single file, or (if fp is NULL) all files. */
int
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fflush(fp)
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FILE *fp;
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{
int r;
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if (fp == NULL) {
rwlock_rdlock(&__sfp_lock);
r = _fwalk(__sflush);
rwlock_unlock(&__sfp_lock);
return r;
}
FLOCKFILE(fp);
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if ((fp->_flags & (__SWR | __SRW)) == 0) {
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errno = EBADF;
r = EOF;
} else {
r = __sflush(fp);
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}
FUNLOCKFILE(fp);
return r;
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}
int
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__sflush(fp)
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FILE *fp;
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{
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unsigned char *p;
int n, t;
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t = fp->_flags;
if ((t & __SWR) == 0)
return (0);
if ((p = fp->_bf._base) == NULL)
return (0);
n = fp->_p - p; /* write this much */
/*
* Set these immediately to avoid problems with longjmp and to allow
* exchange buffering (via setvbuf) in user write function.
*/
fp->_p = p;
fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size;
for (; n > 0; n -= t, p += t) {
t = (*fp->_write)(fp->_cookie, (char *)p, n);
if (t <= 0) {
fp->_flags |= __SERR;
return (EOF);
}
}
return (0);
}