84 lines
3.1 KiB
C
84 lines
3.1 KiB
C
/* $OpenBSD: wbuf.c,v 1.9 2005/08/08 08:05:36 espie 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; fflush()
|
|
* 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 (fflush(fp))
|
|
return (EOF);
|
|
n = 0;
|
|
}
|
|
fp->_w--;
|
|
*fp->_p++ = c;
|
|
if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n'))
|
|
if (fflush(fp))
|
|
return (EOF);
|
|
return (c);
|
|
}
|