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File: [local] / src / usr.bin / vi / ex / ex_undo.c (download)

Revision 1.5, Tue Oct 27 23:59:47 2009 UTC (14 years, 7 months ago) by deraadt
Branch: MAIN
CVS Tags: OPENBSD_5_6_BASE, OPENBSD_5_6, OPENBSD_5_5_BASE, OPENBSD_5_5, OPENBSD_5_4_BASE, OPENBSD_5_4, OPENBSD_5_3_BASE, OPENBSD_5_3, OPENBSD_5_2_BASE, OPENBSD_5_2, OPENBSD_5_1_BASE, OPENBSD_5_1, OPENBSD_5_0_BASE, OPENBSD_5_0, OPENBSD_4_9_BASE, OPENBSD_4_9, OPENBSD_4_8_BASE, OPENBSD_4_8, OPENBSD_4_7_BASE, OPENBSD_4_7
Changes since 1.4: +1 -5 lines 

rcsid[] and sccsid[] and copyright[] are essentially unmaintained (and
unmaintainable).  these days, people use source.  these id's do not provide
any benefit, and do hurt the small install media
(the 33,000 line diff is essentially mechanical)
ok with the idea millert, ok dms

/*	$OpenBSD: ex_undo.c,v 1.5 2009/10/27 23:59:47 deraadt Exp $	*/

/*-
 * Copyright (c) 1992, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *	Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>

#include <bitstring.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>

#include "../common/common.h"

/*
 * ex_undo -- u
 *	Undo the last change.
 *
 * PUBLIC: int ex_undo(SCR *, EXCMD *);
 */
int
ex_undo(sp, cmdp)
	SCR *sp;
	EXCMD *cmdp;
{
	EXF *ep;
	MARK m;

	/*
	 * !!!
	 * Historic undo always set the previous context mark.
	 */
	m.lno = sp->lno;
	m.cno = sp->cno;
	if (mark_set(sp, ABSMARK1, &m, 1))
		return (1);

	/*
	 * !!!
	 * Multiple undo isn't available in ex, as there's no '.' command.
	 * Whether 'u' is undo or redo is toggled each time, unless there
	 * was a change since the last undo, in which case it's an undo.
	 */
	ep = sp->ep;
	if (!F_ISSET(ep, F_UNDO)) {
		F_SET(ep, F_UNDO);
		ep->lundo = FORWARD;
	}
	switch (ep->lundo) {
	case BACKWARD:
		if (log_forward(sp, &m))
			return (1);
		ep->lundo = FORWARD;
		break;
	case FORWARD:
		if (log_backward(sp, &m))
			return (1);
		ep->lundo = BACKWARD;
		break;
	case NOTSET:
		abort();
	}
	sp->lno = m.lno;
	sp->cno = m.cno;
	return (0);
}