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/* $OpenBSD: wbuf.c,v 1.10 2009/10/21 16:04:23 guenther Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* 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. 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 <stdio.h>
#include <errno.h>
#include "local.h"
/*
* Write the given character into the (probably full) buffer for
* the given file. Flush the buffer out if it is or becomes full,
* or if c=='\n' and the file is line buffered.
*/
int
__swbuf(int c, FILE *fp)
{
int n;
_SET_ORIENTATION(fp, -1);
/*
* In case we cannot write, or longjmp takes us out early,
* make sure _w is 0 (if fully- or un-buffered) or -_bf._size
* (if line buffered) so that we will get called again.
* If we did not do this, a sufficient number of putc()
* calls might wrap _w from negative to positive.
*/
fp->_w = fp->_lbfsize;
if (cantwrite(fp)) {
errno = EBADF;
return (EOF);
}
c = (unsigned char)c;
/*
* If it is completely full, flush it out. Then, in any case,
* stuff c into the buffer. If this causes the buffer to fill
* completely, or if c is '\n' and the file is line buffered,
* flush it (perhaps a second time). The second flush will always
* happen on unbuffered streams, where _bf._size==1; __sflush()
* guarantees that putc() will always call wbuf() by setting _w
* to 0, so we need not do anything else.
*/
n = fp->_p - fp->_bf._base;
if (n >= fp->_bf._size) {
if (__sflush(fp))
return (EOF);
n = 0;
}
fp->_w--;
*fp->_p++ = c;
if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n'))
if (__sflush(fp))
return (EOF);
return (c);
}
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