wsetup.c

VXWORKS源代码

/* wsetbuf.c - file for stdio.h */

/* Copyright 1992 Wind River Systems, Inc. */

/*
modification history
--------------------
01b,20sep92,smb  documentation additions
01a,29jul92,smb  taken from UCB stdio
*/

/*
DESCRIPTION
 * Copyright (c) 1990 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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 FILE: stdio.h, stdlib.h

SEE ALSO: American National Standard X3.159-1989

NOMANUAL
*/

#include "vxWorks.h"
#include "stdio.h"
#include "stdlib.h"
#include "private/stdioP.h"


/******************************************************************************
*
* __swsetup - 
*
* Various output routines call wsetup to be sure it is safe to write,
* because either _flags does not include __SWR, or _buf is NULL.
* _wsetup returns 0 if OK to write, nonzero otherwise.
*
* 
* INCLUDE: stdio.h 
*
* RETURNS: 
* NOMANUAL
*/

int __swsetup
    (
    FAST FILE *fp
    )
    {
    /* If we are not writing, we had better be reading and writing */

    if ((fp->_flags & __SWR) == 0) 
	{
	if ((fp->_flags & __SRW) == 0)
	    return (EOF);

	if (fp->_flags & __SRD) 
	    {
	    /* clobber any ungetc data */
	    if (HASUB(fp))
		FREEUB(fp);

	    fp->_flags &= ~(__SRD|__SEOF);
	    fp->_r = 0;
	    fp->_p = fp->_bf._base;
	    }

	fp->_flags |= __SWR;
	}

    /* Make a buffer if necessary, then set _w */

    if (fp->_bf._base == NULL)
	__smakebuf (fp);

    if (fp->_flags & __SLBF) 
	{
	/*
	 * It is line buffered, so make _lbfsize be -_bufsize
	 * for the putc() macro.  We will change _lbfsize back
	 * to 0 whenever we turn off __SWR.
	 */
	fp->_w = 0;
	fp->_lbfsize = -fp->_bf._size;
	}
    else
	fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size;

    return (0);
    }