unsync.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char	*sccsid = "@(#)UNSYNC.c	1.2	(ULTRIX)	1/27/86";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
*
*			Modification History
*
*		David Metsky,	27-Jan-86
*
* 001	Replaced old version with BSD 4.3 version as part of upgrade
*
*	Based on:	UNSYNC.c	1.4 (Berkeley)	10/28/83
*
*************************************************************************/

#include "h00vars.h"

/*
 * push back last char read to prepare for formatted read
 */
UNSYNC(curfile)

	register struct iorec	*curfile;
{
	if (curfile->funit & FWRITE) {
		ERROR("%s: Attempt to read, but open for writing\n",
			curfile->pfname);
		return;
	}
	if (curfile->funit & EOFF) {
		ERROR("%s: Tried to read past end of file\n", curfile->pfname);
		return;
	}
	if ((curfile->funit & SYNC) == 0) {
		ungetc(*curfile->fileptr, curfile->fbuf);
	}
	curfile->funit &= ~EOLN;
	curfile->funit |= SYNC;
}