NetBSD/usr.bin/vi/ex/ex_undo.c

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/*-
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*/
#ifndef lint
static char sccsid[] = "@(#)ex_undo.c 8.4 (Berkeley) 12/29/93";
#endif /* not lint */
#include <sys/types.h>
#include "vi.h"
#include "excmd.h"
/*
* ex_undol -- U
* Undo changes to this line.
*/
int
ex_undol(sp, ep, cmdp)
SCR *sp;
EXF *ep;
EXCMDARG *cmdp;
{
if (log_setline(sp, ep))
return (1);
sp->cno = 0;
return (0);
}
/*
* ex_undo -- u
* Undo the last change.
*/
int
ex_undo(sp, ep, cmdp)
SCR *sp;
EXF *ep;
EXCMDARG *cmdp;
{
MARK m;
/*
* !!!
* 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.
*/
if (!F_ISSET(ep, F_UNDO)) {
F_SET(ep, F_UNDO);
ep->lundo = FORWARD;
}
switch (ep->lundo) {
case BACKWARD:
if (log_forward(sp, ep, &m))
return (1);
ep->lundo = FORWARD;
break;
case FORWARD:
if (log_backward(sp, ep, &m))
return (1);
ep->lundo = BACKWARD;
break;
case NOTSET:
abort();
}
sp->lno = m.lno;
sp->cno = m.cno;
return (0);
}