1 /*
2 * Copyright (C) 1984-2012 Mark Nudelman
3 * Modified for use with illumos by Garrett D'Amore.
4 * Copyright 2014 Garrett D'Amore <garrett@damore.org>
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Less License, as specified in the README file.
8 *
9 * For more information, see the README file.
10 */
11
12 /*
13 * Routines to perform bracket matching functions.
14 */
15
16 #include "less.h"
17 #include "position.h"
18
19 /*
20 * Try to match the n-th open bracket
21 * which appears in the top displayed line (forwdir),
22 * or the n-th close bracket
23 * which appears in the bottom displayed line (!forwdir).
24 * The characters which serve as "open bracket" and
25 * "close bracket" are given.
26 */
27 void
match_brac(int obrac,int cbrac,int forwdir,int n)28 match_brac(int obrac, int cbrac, int forwdir, int n)
29 {
30 int c;
31 int nest;
32 off_t pos;
33 int (*chget)(void);
34
35 /*
36 * Seek to the line containing the open bracket.
37 * This is either the top or bottom line on the screen,
38 * depending on the type of bracket.
39 */
40 pos = position((forwdir) ? TOP : BOTTOM);
41 if (pos == -1 || ch_seek(pos)) {
42 if (forwdir)
43 error("Nothing in top line", NULL);
44 else
45 error("Nothing in bottom line", NULL);
46 return;
47 }
48
49 /*
50 * Look thru the line to find the open bracket to match.
51 */
52 do {
53 if ((c = ch_forw_get()) == '\n' || c == EOI) {
54 if (forwdir)
55 error("No bracket in top line", NULL);
56 else
57 error("No bracket in bottom line", NULL);
58 return;
59 }
60 } while (c != obrac || --n > 0);
61
62 /*
63 * Position the file just "after" the open bracket
64 * (in the direction in which we will be searching).
65 * If searching forward, we are already after the bracket.
66 * If searching backward, skip back over the open bracket.
67 */
68 if (!forwdir)
69 (void) ch_back_get();
70
71 /*
72 * Search the file for the matching bracket.
73 */
74 chget = (forwdir) ? ch_forw_get : ch_back_get;
75 nest = 0;
76 while ((c = (*chget)()) != EOI) {
77 if (c == obrac) {
78 if (nest == INT_MAX)
79 break;
80 nest++;
81 } else if (c == cbrac && --nest < 0) {
82 /*
83 * Found the matching bracket.
84 * If searching backward, put it on the top line.
85 * If searching forward, put it on the bottom line.
86 */
87 jump_line_loc(ch_tell(), forwdir ? -1 : 1);
88 return;
89 }
90 }
91 error("No matching bracket", NULL);
92 }
93