xref: /openbsd-src/usr.bin/vi/vi/v_match.c (revision a0b15055027e40896769bb61ce100804e66327ea)
1 /*	$OpenBSD: v_match.c,v 1.9 2016/01/06 22:28:52 millert Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 1992, 1993, 1994, 1995, 1996
7  *	Keith Bostic.  All rights reserved.
8  *
9  * See the LICENSE file for redistribution information.
10  */
11 
12 #include "config.h"
13 
14 #include <sys/types.h>
15 #include <sys/queue.h>
16 #include <sys/time.h>
17 
18 #include <bitstring.h>
19 #include <ctype.h>
20 #include <limits.h>
21 #include <stdio.h>
22 #include <string.h>
23 
24 #include "../common/common.h"
25 #include "vi.h"
26 
27 /*
28  * v_match -- %
29  *	Search to matching character.
30  *
31  * PUBLIC: int v_match(SCR *, VICMD *);
32  */
33 int
v_match(SCR * sp,VICMD * vp)34 v_match(SCR *sp, VICMD *vp)
35 {
36 	VCS cs;
37 	MARK *mp;
38 	size_t cno, len, off;
39 	int cnt, isempty, matchc, startc, (*gc)(SCR *, VCS *);
40 	char *p;
41 
42 	/*
43 	 * !!!
44 	 * Historic practice; ignore the count.
45 	 *
46 	 * !!!
47 	 * Historical practice was to search for the initial character in the
48 	 * forward direction only.
49 	 */
50 	if (db_eget(sp, vp->m_start.lno, &p, &len, &isempty)) {
51 		if (isempty)
52 			goto nomatch;
53 		return (1);
54 	}
55 	for (off = vp->m_start.cno;; ++off) {
56 		if (off >= len) {
57 nomatch:		msgq(sp, M_BERR, "No match character on this line");
58 			return (1);
59 		}
60 		switch (startc = p[off]) {
61 		case '(':
62 			matchc = ')';
63 			gc = cs_next;
64 			break;
65 		case ')':
66 			matchc = '(';
67 			gc = cs_prev;
68 			break;
69 		case '[':
70 			matchc = ']';
71 			gc = cs_next;
72 			break;
73 		case ']':
74 			matchc = '[';
75 			gc = cs_prev;
76 			break;
77 		case '{':
78 			matchc = '}';
79 			gc = cs_next;
80 			break;
81 		case '}':
82 			matchc = '{';
83 			gc = cs_prev;
84 			break;
85 		case '<':
86 			matchc = '>';
87 			gc = cs_next;
88 			break;
89 		case '>':
90 			matchc = '<';
91 			gc = cs_prev;
92 			break;
93 		default:
94 			continue;
95 		}
96 		break;
97 	}
98 
99 	cs.cs_lno = vp->m_start.lno;
100 	cs.cs_cno = off;
101 	if (cs_init(sp, &cs))
102 		return (1);
103 	for (cnt = 1;;) {
104 		if (gc(sp, &cs))
105 			return (1);
106 		if (cs.cs_flags != 0) {
107 			if (cs.cs_flags == CS_EOF || cs.cs_flags == CS_SOF)
108 				break;
109 			continue;
110 		}
111 		if (cs.cs_ch == startc)
112 			++cnt;
113 		else if (cs.cs_ch == matchc && --cnt == 0)
114 			break;
115 	}
116 	if (cnt) {
117 		msgq(sp, M_BERR, "Matching character not found");
118 		return (1);
119 	}
120 
121 	vp->m_stop.lno = cs.cs_lno;
122 	vp->m_stop.cno = cs.cs_cno;
123 
124 	/*
125 	 * If moving right, non-motion commands move to the end of the range.
126 	 * Delete and yank stay at the start.
127 	 *
128 	 * If moving left, all commands move to the end of the range.
129 	 *
130 	 * !!!
131 	 * Don't correct for leftward movement -- historic vi deleted the
132 	 * starting cursor position when deleting to a match.
133 	 */
134 	if (vp->m_start.lno < vp->m_stop.lno ||
135 	    (vp->m_start.lno == vp->m_stop.lno &&
136 	    vp->m_start.cno < vp->m_stop.cno))
137 		vp->m_final = ISMOTION(vp) ? vp->m_start : vp->m_stop;
138 	else
139 		vp->m_final = vp->m_stop;
140 
141 	/*
142 	 * !!!
143 	 * If the motion is across lines, and the earliest cursor position
144 	 * is at or before any non-blank characters in the line, i.e. the
145 	 * movement is cutting all of the line's text, and the later cursor
146 	 * position has nothing other than whitespace characters between it
147 	 * and the end of its line, the buffer is in line mode.
148 	 */
149 	if (!ISMOTION(vp) || vp->m_start.lno == vp->m_stop.lno)
150 		return (0);
151 	mp = vp->m_start.lno < vp->m_stop.lno ? &vp->m_start : &vp->m_stop;
152 	if (mp->cno != 0) {
153 		cno = 0;
154 		if (nonblank(sp, mp->lno, &cno))
155 			return (1);
156 		if (cno < mp->cno)
157 			return (0);
158 	}
159 	mp = vp->m_start.lno < vp->m_stop.lno ? &vp->m_stop : &vp->m_start;
160 	if (db_get(sp, mp->lno, DBG_FATAL, &p, &len))
161 		return (1);
162 	for (p += mp->cno + 1, len -= mp->cno; --len; ++p)
163 		if (!isblank(*p))
164 			return (0);
165 	F_SET(vp, VM_LMODE);
166 	return (0);
167 }
168