104 lines
3.0 KiB
C
104 lines
3.0 KiB
C
/*-
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* Copyright (c) 1992, 1993, 1994
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)ex_undo.c 8.9 (Berkeley) 8/17/94";
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#endif /* not lint */
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#include <sys/types.h>
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#include <sys/queue.h>
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#include <sys/time.h>
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#include <bitstring.h>
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#include <limits.h>
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#include <signal.h>
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#include <stdio.h>
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#include <termios.h>
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#include "compat.h"
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#include <db.h>
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#include <regex.h>
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#include "vi.h"
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#include "excmd.h"
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/*
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* ex_undo -- u
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* Undo the last change.
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*/
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int
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ex_undo(sp, ep, cmdp)
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SCR *sp;
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EXF *ep;
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EXCMDARG *cmdp;
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{
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MARK m;
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/*
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* !!!
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* Historic undo always set the previous context mark.
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*/
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m.lno = sp->lno;
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m.cno = sp->cno;
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if (mark_set(sp, ep, ABSMARK1, &m, 1))
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return (1);
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/*
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* !!!
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* Multiple undo isn't available in ex, as there's no '.' command.
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* Whether 'u' is undo or redo is toggled each time, unless there
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* was a change since the last undo, in which case it's an undo.
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*/
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if (!F_ISSET(ep, F_UNDO)) {
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F_SET(ep, F_UNDO);
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ep->lundo = FORWARD;
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}
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switch (ep->lundo) {
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case BACKWARD:
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if (log_forward(sp, ep, &m))
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return (1);
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ep->lundo = FORWARD;
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break;
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case FORWARD:
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if (log_backward(sp, ep, &m))
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return (1);
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ep->lundo = BACKWARD;
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break;
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case NOTSET:
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abort();
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}
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sp->lno = m.lno;
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sp->cno = m.cno;
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return (0);
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}
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