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/* $OpenBSD: fpurge.c,v 1.10 2015/08/31 02:53:57 guenther Exp $ */ |
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/*- |
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* Copyright (c) 1990, 1993 |
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* The Regents of the University of California. All rights reserved. |
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* |
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* This code is derived from software contributed to Berkeley by |
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* Chris Torek. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of the University nor the names of its contributors |
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* may be used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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*/ |
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#include <errno.h> |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include "local.h" |
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/* |
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* fpurge: like fflush, but without writing anything: leave the |
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* given FILE's buffer empty. |
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*/ |
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int |
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fpurge(FILE *fp) |
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{ |
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FLOCKFILE(fp); |
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if (!fp->_flags) { |
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FUNLOCKFILE(fp); |
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errno = EBADF; |
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return(EOF); |
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} |
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if (HASUB(fp)) |
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FREEUB(fp); |
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WCIO_FREE(fp); |
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fp->_p = fp->_bf._base; |
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fp->_r = 0; |
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fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : fp->_bf._size; |
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FUNLOCKFILE(fp); |
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return (0); |
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} |
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DEF_WEAK(fpurge); |