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/* $OpenBSD: wbuf.c,v 1.13 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 <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; __sflush() |
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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 (__sflush(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 (__sflush(fp)) |
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return (EOF); |
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return (c); |
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} |
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DEF_STRONG(__swbuf); |