1*e0b8e63eSJohn Marino /*-
2*e0b8e63eSJohn Marino * Copyright (c) 1992, 1993, 1994
3*e0b8e63eSJohn Marino * The Regents of the University of California. All rights reserved.
4*e0b8e63eSJohn Marino * Copyright (c) 1992, 1993, 1994, 1995, 1996
5*e0b8e63eSJohn Marino * Keith Bostic. All rights reserved.
6*e0b8e63eSJohn Marino *
7*e0b8e63eSJohn Marino * See the LICENSE file for redistribution information.
8*e0b8e63eSJohn Marino */
9*e0b8e63eSJohn Marino
10*e0b8e63eSJohn Marino #include "config.h"
11*e0b8e63eSJohn Marino
12*e0b8e63eSJohn Marino #include <sys/types.h>
13*e0b8e63eSJohn Marino #include <sys/queue.h>
14*e0b8e63eSJohn Marino #include <sys/time.h>
15*e0b8e63eSJohn Marino
16*e0b8e63eSJohn Marino #include <bitstring.h>
17*e0b8e63eSJohn Marino #include <limits.h>
18*e0b8e63eSJohn Marino #include <stdio.h>
19*e0b8e63eSJohn Marino #include <stdlib.h>
20*e0b8e63eSJohn Marino
21*e0b8e63eSJohn Marino #include "../common/common.h"
22*e0b8e63eSJohn Marino
23*e0b8e63eSJohn Marino /*
24*e0b8e63eSJohn Marino * ex_undo -- u
25*e0b8e63eSJohn Marino * Undo the last change.
26*e0b8e63eSJohn Marino *
27*e0b8e63eSJohn Marino * PUBLIC: int ex_undo(SCR *, EXCMD *);
28*e0b8e63eSJohn Marino */
29*e0b8e63eSJohn Marino int
ex_undo(SCR * sp,EXCMD * cmdp)30*e0b8e63eSJohn Marino ex_undo(SCR *sp, EXCMD *cmdp)
31*e0b8e63eSJohn Marino {
32*e0b8e63eSJohn Marino EXF *ep;
33*e0b8e63eSJohn Marino MARK m;
34*e0b8e63eSJohn Marino
35*e0b8e63eSJohn Marino /*
36*e0b8e63eSJohn Marino * !!!
37*e0b8e63eSJohn Marino * Historic undo always set the previous context mark.
38*e0b8e63eSJohn Marino */
39*e0b8e63eSJohn Marino m.lno = sp->lno;
40*e0b8e63eSJohn Marino m.cno = sp->cno;
41*e0b8e63eSJohn Marino if (mark_set(sp, ABSMARK1, &m, 1))
42*e0b8e63eSJohn Marino return (1);
43*e0b8e63eSJohn Marino
44*e0b8e63eSJohn Marino /*
45*e0b8e63eSJohn Marino * !!!
46*e0b8e63eSJohn Marino * Multiple undo isn't available in ex, as there's no '.' command.
47*e0b8e63eSJohn Marino * Whether 'u' is undo or redo is toggled each time, unless there
48*e0b8e63eSJohn Marino * was a change since the last undo, in which case it's an undo.
49*e0b8e63eSJohn Marino */
50*e0b8e63eSJohn Marino ep = sp->ep;
51*e0b8e63eSJohn Marino if (!F_ISSET(ep, F_UNDO)) {
52*e0b8e63eSJohn Marino F_SET(ep, F_UNDO);
53*e0b8e63eSJohn Marino ep->lundo = FORWARD;
54*e0b8e63eSJohn Marino }
55*e0b8e63eSJohn Marino switch (ep->lundo) {
56*e0b8e63eSJohn Marino case BACKWARD:
57*e0b8e63eSJohn Marino if (log_forward(sp, &m))
58*e0b8e63eSJohn Marino return (1);
59*e0b8e63eSJohn Marino ep->lundo = FORWARD;
60*e0b8e63eSJohn Marino break;
61*e0b8e63eSJohn Marino case FORWARD:
62*e0b8e63eSJohn Marino if (log_backward(sp, &m))
63*e0b8e63eSJohn Marino return (1);
64*e0b8e63eSJohn Marino ep->lundo = BACKWARD;
65*e0b8e63eSJohn Marino break;
66*e0b8e63eSJohn Marino case NOTSET:
67*e0b8e63eSJohn Marino abort();
68*e0b8e63eSJohn Marino }
69*e0b8e63eSJohn Marino sp->lno = m.lno;
70*e0b8e63eSJohn Marino sp->cno = m.cno;
71*e0b8e63eSJohn Marino return (0);
72*e0b8e63eSJohn Marino }
73