/* stdio.c - internal misc. routines for stdio.h *//* Copyright 1992 Wind River Systems, Inc. *//*modification history--------------------01b,20sep92,smb  documentation additions01a,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. * *DESCRIPTION OF STDIO STATE VARIABLES * * stdio state variables. * * The following always hold: * *      if (_flags&(__SLBF|__SWR)) == (__SLBF|__SWR), *              _lbfsize is -_bf._size, else _lbfsize is 0 *      if _flags&__SRD, _w is 0 *      if _flags&__SWR, _r is 0 * * This ensures that the getc and putc macros (or inline functions) never * try to write or read from a file that is in `read' or `write' mode. * (Moreover, they can, and do, automatically switch from read mode to * write mode, and back, on "r+" and "w+" files.) * * _lbfsize is used only to make the inline line-buffered output stream * code as compact as possible. * * _ub, _up, and _ur are used when ungetc() pushes back more characters * than fit in the current _bf, or when ungetc() pushes back a character * that does not match the previous one in _bf.  When this happens, * _ub._base becomes non-nil (i.e., a stream has ungetc() data iff * _ub._base!=NULL) and _up and _ur save the current values of _p and _r.INCLUDE FILE: stdio.h, fcntl.h, unistd.hSEE ALSO: American National Standard X3.159-1989NOMANUAL*/#include "vxWorks.h"#include "stdio.h"#include "fcntl.h"#include "unistd.h"#include "private/stdioP.h"/******************************************************************************** __sread - internal routine* * INCLUDE: stdio.h ** RETURNS: * NOMANUAL*/int __sread    (    FAST FILE *	fp,    char *	buf,    int		n    )    {    FAST int ret;        ret = read (fp->_file, buf, n);    if (ret >= 0)		/* if read succeeded, update current offset */	fp->_offset += ret;    else	fp->_flags &= ~__SOFF;	/* paranoia */    return (ret);    }/******************************************************************************** __swrite - internal routine* * INCLUDE: stdio.h ** RETURNS: * NOMANUAL*/int __swrite    (    register FILE * fp,    char const *    buf,    int             n    )    {    if (fp->_flags & __SAPP)	(void) lseek (fp->_file, (off_t)0, SEEK_END);    fp->_flags &= ~__SOFF;	/* in case FAPPEND mode is set */    return (write (fp->_file, CHAR_FROM_CONST(buf), n));    }/******************************************************************************** __sseek - internal routine* * INCLUDE: stdio.h ** RETURNS: * NOMANUAL*/fpos_t __sseek    (    FAST FILE *	fp,    fpos_t	offset,    int		whence    )    {    FAST off_t ret;        ret = lseek (fp->_file, (off_t)offset, whence);    if (ret == -1L)	fp->_flags &= ~__SOFF;    else 	{	fp->_flags |= __SOFF;	fp->_offset = ret;	}    return (ret);    }/******************************************************************************** __sclose - internal routine* * INCLUDE: stdio.h ** RETURNS: * NOMANUAL*/int __sclose    (    FILE * fp    )    {    int result	= 0;    int fd	= fp->_file;    if ((fd >= 0) && (fd < 3))		/* careful of closing standard fds! */	result = 0;    else if (close (fd) < 0)	result = EOF;    return (result);    }