summaryrefslogtreecommitdiff
path: root/usr.bin/less/mark.c
blob: 4641a29385bb072b933e3f208a76395f803644d6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
/*	$OpenBSD: mark.c,v 1.3 2001/11/19 19:02:14 mpech Exp $	*/

/*
 * Copyright (c) 1984,1985,1989,1994,1995  Mark Nudelman
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice in the documentation and/or other materials provided with 
 *    the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#include "less.h"
#include "position.h"

extern IFILE curr_ifile;
extern int sc_height;
extern int jump_sline;

/*
 * A mark is an ifile (input file) plus a position within the file.
 */
struct mark {
	IFILE m_ifile;
	struct scrpos m_scrpos;
};

/*
 * The table of marks.
 * Each mark is identified by a lowercase or uppercase letter.
 */
#define	NMARKS		(2*26)		/* a-z, A-Z */
static struct mark marks[NMARKS];

/*
 * Special mark for the "last mark"; addressed by the apostrophe.
 */
static struct mark lmark;

/*
 * Initialize the mark table to show no marks are set.
 */
	public void
init_mark()
{
	int i;

	for (i = 0;  i < NMARKS;  i++)
		marks[i].m_scrpos.pos = NULL_POSITION;
	lmark.m_scrpos.pos = NULL_POSITION;
}

/*
 * See if a mark letter is valid (between a and z).
 */
	static struct mark *
getumark(c)
	int c;
{
	if (c >= 'a' && c <= 'z')
		return (&marks[c-'a']);

	if (c >= 'A' && c <= 'Z')
		return (&marks[c-'A'+26]);

	error("Invalid mark letter", NULL_PARG);
	return (NULL);
}

/*
 * Get the mark structure identified by a character.
 * The mark struct may come either from the mark table
 * or may be constructed on the fly for certain characters like ^, $.
 */
	static struct mark *
getmark(c)
	int c;
{
	struct mark *m;
	static struct mark sm;

	switch (c)
	{
	case '^':
		/*
		 * Beginning of the current file.
		 */
		m = &sm;
		m->m_scrpos.pos = ch_zero();
		m->m_scrpos.ln = 0;
		m->m_ifile = curr_ifile;
		break;
	case '$':
		/*
		 * End of the current file.
		 */
		if (ch_end_seek())
		{
			error("Cannot seek to end of file", NULL_PARG);
			return (NULL);
		}
		m = &sm;
		m->m_scrpos.pos = ch_tell();
		m->m_scrpos.ln = sc_height-1;
		m->m_ifile = curr_ifile;
		break;
	case '.':
		/*
		 * Current position in the current file.
		 */
		m = &sm;
		m->m_scrpos.pos = ch_tell();
		m->m_scrpos.ln = 0;
		m->m_ifile = curr_ifile;
		break;
	case '\'':
		/*
		 * The "last mark".
		 */
		m = &lmark;
		break;
	default:
		/*
		 * Must be a user-defined mark.
		 */
		m = getumark(c);
		if (m == NULL)
			break;
		if (m->m_scrpos.pos == NULL_POSITION)
		{
			error("Mark not set", NULL_PARG);
			return (NULL);
		}
		break;
	}
	return (m);
}

/*
 * Is a mark letter is invalid?
 */
	public int
badmark(c)
	int c;
{
	return (getmark(c) == NULL);
}

/*
 * Set a user-defined mark.
 */
	public void
setmark(c)
	int c;
{
	struct mark *m;
	struct scrpos scrpos;

	m = getumark(c);
	if (m == NULL)
		return;
	get_scrpos(&scrpos);
	m->m_scrpos = scrpos;
	m->m_ifile = curr_ifile;
}

/*
 * Set lmark (the mark named by the apostrophe).
 */
	public void
lastmark()
{
	struct scrpos scrpos;

	get_scrpos(&scrpos);
	if (scrpos.pos == NULL_POSITION)
		return;
	lmark.m_scrpos = scrpos;
	lmark.m_ifile = curr_ifile;
}

/*
 * Go to a mark.
 */
	public void
gomark(c)
	int c;
{
	struct mark *m;
	struct scrpos scrpos;

	m = getmark(c);
	if (m == NULL)
		return;

	/*
	 * If we're trying to go to the lastmark and 
	 * it has not been set to anything yet,
	 * set it to the beginning of the current file.
	 */
	if (m == &lmark && m->m_scrpos.pos == NULL_POSITION)
	{
		m->m_ifile = curr_ifile;
		m->m_scrpos.pos = ch_zero();
		m->m_scrpos.ln = jump_sline;
	}

	/*
	 * If we're using lmark, we must save the screen position now,
	 * because if we call edit_ifile() below, lmark will change.
	 * (We save the screen position even if we're not using lmark.)
	 */
	scrpos = m->m_scrpos;
	if (m->m_ifile != curr_ifile)
	{
		/*
		 * Not in the current file; edit the correct file.
		 */
		if (edit_ifile(m->m_ifile))
			return;
	}

	jump_loc(scrpos.pos, scrpos.ln);
}

/*
 * Return the position associated with a given mark letter.
 *
 * We don't return which screen line the position 
 * is associated with, but this doesn't matter much,
 * because it's always the first non-blank line on the screen.
 */
	public POSITION
markpos(c)
	int c;
{
	struct mark *m;

	m = getmark(c);
	if (m == NULL)
		return (NULL_POSITION);

	if (m->m_ifile != curr_ifile)
	{
		error("Mark not in current file", NULL_PARG);
		return (NULL_POSITION);
	}
	return (m->m_scrpos.pos);
}