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/* $OpenBSD: refill.c,v 1.11 2009/11/09 00:18:27 kurt 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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static int |
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lflush(FILE *fp) |
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{ |
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if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR)) |
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return (__sflush_locked(fp)); /* ignored... */ |
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return (0); |
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} |
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/* |
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* Refill a stdio buffer. |
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* Return EOF on eof or error, 0 otherwise. |
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*/ |
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int |
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__srefill(FILE *fp) |
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{ |
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/* make sure stdio is set up */ |
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if (!__sdidinit) |
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__sinit(); |
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fp->_r = 0; /* largely a convenience for callers */ |
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/* SysV does not make this test; take it out for compatibility */ |
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if (fp->_flags & __SEOF) |
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return (EOF); |
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/* if not already reading, have to be reading and writing */ |
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if ((fp->_flags & __SRD) == 0) { |
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if ((fp->_flags & __SRW) == 0) { |
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errno = EBADF; |
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fp->_flags |= __SERR; |
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return (EOF); |
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} |
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/* switch to reading */ |
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if (fp->_flags & __SWR) { |
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if (__sflush(fp)) |
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return (EOF); |
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fp->_flags &= ~__SWR; |
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fp->_w = 0; |
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fp->_lbfsize = 0; |
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} |
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fp->_flags |= __SRD; |
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} else { |
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/* |
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* We were reading. If there is an ungetc buffer, |
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* we must have been reading from that. Drop it, |
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* restoring the previous buffer (if any). If there |
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* is anything in that buffer, return. |
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*/ |
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if (HASUB(fp)) { |
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FREEUB(fp); |
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if ((fp->_r = fp->_ur) != 0) { |
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fp->_p = fp->_up; |
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return (0); |
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} |
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} |
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} |
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if (fp->_bf._base == NULL) |
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__smakebuf(fp); |
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/* |
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* Before reading from a line buffered or unbuffered file, |
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* flush all line buffered output files, per the ANSI C |
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* standard. |
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*/ |
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if (fp->_flags & (__SLBF|__SNBF)) { |
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/* Ignore this file in _fwalk to avoid potential deadlock. */ |
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fp->_flags |= __SIGN; |
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(void) _fwalk(lflush); |
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fp->_flags &= ~__SIGN; |
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/* Now flush this file without locking it. */ |
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if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR)) |
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__sflush(fp); |
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} |
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fp->_p = fp->_bf._base; |
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fp->_r = (*fp->_read)(fp->_cookie, (char *)fp->_p, fp->_bf._size); |
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fp->_flags &= ~__SMOD; /* buffer contents are again pristine */ |
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if (fp->_r <= 0) { |
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if (fp->_r == 0) |
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fp->_flags |= __SEOF; |
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else { |
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fp->_r = 0; |
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fp->_flags |= __SERR; |
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} |
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return (EOF); |
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} |
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return (0); |
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} |