freebsd-skq/contrib/nvi/ex/ex_undo.c
Peter Wemm f0957ccae4 Update nvi-1.79 to 2.1.1-4334a8297f
This is the gsoc-2011 project to clean up and backport multibyte support
from other nvi forks in a form we can use.

USE_WIDECHAR is on unless building for the rescue crunchgen. This should
allow editing in the native locale encoding.

USE_ICONV depends on make.conf having 'WITH_ICONV=YES' for now.  This
adds the ability to do things like edit a KOI8-R file while having $LANG
set to (say) en_US.UTF-8.  iconv is used to transcode the characters for
display.

Other points:
* It uses gencat and catopen/etc instead of homegrown msg catalog stuff.
* A lot of stuff has been trimmed out, eg: the perl and tcl bindings which
  we could never use in base anyway.
* It uses ncursesw when in widechar mode.  This could be interesting.

GSoC info: http://www.google-melange.com/gsoc/proposal/review/google/gsoc2011/zy/1
Repo at: https://github.com/lichray/nvi2

Obtained from:  Zhihao Yuan <lichray@gmail.com>
2013-08-11 20:03:12 +00:00

77 lines
1.5 KiB
C

/*-
* 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"
#ifndef lint
static const char sccsid[] = "$Id: ex_undo.c,v 10.7 2001/06/25 15:19:21 skimo Exp $";
#endif /* not lint */
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.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 __P((SCR *, EXCMD *));
*/
int
ex_undo(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);
}