/* freopen.c - reopen a file. stdio.h *//* Copyright 1992-1993 Wind River Systems, Inc. *//*modification history--------------------01c,05mar93,jdi  documentation cleanup for 5.1.01b,20sep92,smb  documentation additions01a,29jul92,jcf  added memory reclaimation.	   +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, sys/types.h, sys/stat.h, fcntl.h, error.h, unistd.h, 	      stdlib.hSEE ALSO: American National Standard X3.159-1989NOMANUAL*/#include "vxWorks.h"#include "stdio.h"#include "ioLib.h"#include "sys/types.h"#include "sys/stat.h"#include "fcntl.h"#include "errno.h"#include "unistd.h"#include "stdlib.h"#include "objLib.h"#include "private/stdioP.h"/******************************************************************************** freopen - open a file specified by name (ANSI)** This routine opens a file whose name is the string pointed to by <file>* and associates it with a specified stream <fp>.* The <mode> argument is used just as in the fopen() function.** This routine first attempts to close any file that is associated* with the specified stream.  Failure to close the file successfully is* ignored. The error and end-of-file indicators for the stream are cleared.** Typically, freopen() is used to attach the already-open streams* `stdin', `stdout', and `stderr' to other files.* * INCLUDE FILES: stdio.h ** RETURNS:* The value of <fp>, or a null pointer if the open operation fails.** SEE ALSO: fopen()*/FILE * freopen    (    const char *  file,		/* name of file */    const char *  mode,		/* mode */    FAST FILE *	  fp		/* stream */    )    {    FAST int	f;    int		flags;    int		oflags;    int		sverrno;    BOOL	isopen = TRUE;			/* its already open */    if (OBJ_VERIFY (fp, fpClassId) != OK)	return (NULL);    if ((flags = __sflags (mode, &oflags)) == 0) 	{	(void) fclose (fp);	return (NULL);	}    /*     * There are actually programs that depend on being able to "freopen"     * descriptors that weren't originally open.  Keep this from breaking.     * Remember whether the stream was open to begin with, and which file     * descriptor (if any) was associated with it.  If it was attached to     * a descriptor, defer closing it; freopen("/dev/stdin", "r", stdin)     * should work.  This is unnecessary if it was not a Unix file.     */    if (fp->_flags & __SWR)			/* flush the stream though */	(void) __sflush(fp); 			/* ANSI doesn't require this */    if (fp->_file < 0)				/* need to close the fp? */	{	(void) __sclose (fp);	isopen = FALSE;	}    /* Get a new descriptor to refer to the new file. */    f = open (file, oflags, DEFFILEMODE);    if ((f < 0) && isopen)	{	/* If out of fd's close the old one and try again. */	if ((errno == ENFILE) || (errno == EMFILE))	    {	    (void) __sclose (fp);	    isopen = FALSE;	    f = open (file, oflags, DEFFILEMODE);	    }	}    sverrno = errno;    /*     * Finish closing fp.  Even if the open succeeded above, we cannot     * keep fp->_base: it may be the wrong size.  This loses the effect     * of any setbuffer calls, but stdio has always done this before.     */    if (isopen)	(void) __sclose (fp);    if (fp->_flags & __SMBF)	free ((char *)fp->_bf._base);    fp->_w		= 0;    fp->_r		= 0;    fp->_p		= NULL;    fp->_bf._base	= NULL;    fp->_bf._size	= 0;    fp->_lbfsize	= 0;    if (HASUB(fp))	FREEUB(fp);    fp->_ub._size	= 0;    if (HASLB(fp))	FREELB(fp);    fp->_lb._size	= 0;    if ((f < 0) && (fp->_flags != 0))	{				/* did not get it after all */	fp->_flags = 0;			/* set it free */	stdioFpDestroy (fp);		/* destroy file pointer */	errno = sverrno;		/* restore in case _close clobbered */	return (NULL);	}    fp->_flags	= flags;    fp->_file	= f;    return (fp);    }