85 lines
3.1 KiB
C
85 lines
3.1 KiB
C
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/* $OpenBSD: wbuf.c,v 1.9 2005/08/08 08:05:36 espie 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 <stdio.h>
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#include <errno.h>
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#include "local.h"
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/*
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* Write the given character into the (probably full) buffer for
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* the given file. Flush the buffer out if it is or becomes full,
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* or if c=='\n' and the file is line buffered.
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*/
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int
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__swbuf(int c, FILE *fp)
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{
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int n;
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_SET_ORIENTATION(fp, -1);
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/*
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* In case we cannot write, or longjmp takes us out early,
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* make sure _w is 0 (if fully- or un-buffered) or -_bf._size
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* (if line buffered) so that we will get called again.
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* If we did not do this, a sufficient number of putc()
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* calls might wrap _w from negative to positive.
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*/
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fp->_w = fp->_lbfsize;
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if (cantwrite(fp)) {
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errno = EBADF;
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return (EOF);
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}
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c = (unsigned char)c;
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/*
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* If it is completely full, flush it out. Then, in any case,
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* stuff c into the buffer. If this causes the buffer to fill
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* completely, or if c is '\n' and the file is line buffered,
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* flush it (perhaps a second time). The second flush will always
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* happen on unbuffered streams, where _bf._size==1; fflush()
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* guarantees that putc() will always call wbuf() by setting _w
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* to 0, so we need not do anything else.
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*/
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n = fp->_p - fp->_bf._base;
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if (n >= fp->_bf._size) {
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if (fflush(fp))
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return (EOF);
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n = 0;
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}
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fp->_w--;
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*fp->_p++ = c;
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if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n'))
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if (fflush(fp))
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return (EOF);
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return (c);
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}
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