xref: /openbsd-src/usr.bin/less/mark.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*
2  * Copyright (C) 1984-2011  Mark Nudelman
3  *
4  * You may distribute under the terms of either the GNU General Public
5  * License or the Less License, as specified in the README file.
6  *
7  * For more information about less, or for information on how to
8  * contact the author, see the README file.
9  */
10 
11 
12 #include "less.h"
13 
14 extern IFILE curr_ifile;
15 extern int sc_height;
16 extern int jump_sline;
17 
18 /*
19  * A mark is an ifile (input file) plus a position within the file.
20  */
21 struct mark {
22 	IFILE m_ifile;
23 	struct scrpos m_scrpos;
24 };
25 
26 /*
27  * The table of marks.
28  * Each mark is identified by a lowercase or uppercase letter.
29  * The final one is lmark, for the "last mark"; addressed by the apostrophe.
30  */
31 #define	NMARKS		((2*26)+1)	/* a-z, A-Z, lastmark */
32 #define	LASTMARK	(NMARKS-1)
33 static struct mark marks[NMARKS];
34 
35 /*
36  * Initialize the mark table to show no marks are set.
37  */
38 	public void
39 init_mark()
40 {
41 	int i;
42 
43 	for (i = 0;  i < NMARKS;  i++)
44 		marks[i].m_scrpos.pos = NULL_POSITION;
45 }
46 
47 /*
48  * See if a mark letter is valid (between a and z).
49  */
50 	static struct mark *
51 getumark(c)
52 	int c;
53 {
54 	if (c >= 'a' && c <= 'z')
55 		return (&marks[c-'a']);
56 
57 	if (c >= 'A' && c <= 'Z')
58 		return (&marks[c-'A'+26]);
59 
60 	error("Invalid mark letter", NULL_PARG);
61 	return (NULL);
62 }
63 
64 /*
65  * Get the mark structure identified by a character.
66  * The mark struct may come either from the mark table
67  * or may be constructed on the fly for certain characters like ^, $.
68  */
69 	static struct mark *
70 getmark(c)
71 	int c;
72 {
73 	register struct mark *m;
74 	static struct mark sm;
75 
76 	switch (c)
77 	{
78 	case '^':
79 		/*
80 		 * Beginning of the current file.
81 		 */
82 		m = &sm;
83 		m->m_scrpos.pos = ch_zero();
84 		m->m_scrpos.ln = 0;
85 		m->m_ifile = curr_ifile;
86 		break;
87 	case '$':
88 		/*
89 		 * End of the current file.
90 		 */
91 		if (ch_end_seek())
92 		{
93 			error("Cannot seek to end of file", NULL_PARG);
94 			return (NULL);
95 		}
96 		m = &sm;
97 		m->m_scrpos.pos = ch_tell();
98 		m->m_scrpos.ln = sc_height-1;
99 		m->m_ifile = curr_ifile;
100 		break;
101 	case '.':
102 		/*
103 		 * Current position in the current file.
104 		 */
105 		m = &sm;
106 		get_scrpos(&m->m_scrpos);
107 		m->m_ifile = curr_ifile;
108 		break;
109 	case '\'':
110 		/*
111 		 * The "last mark".
112 		 */
113 		m = &marks[LASTMARK];
114 		break;
115 	default:
116 		/*
117 		 * Must be a user-defined mark.
118 		 */
119 		m = getumark(c);
120 		if (m == NULL)
121 			break;
122 		if (m->m_scrpos.pos == NULL_POSITION)
123 		{
124 			error("Mark not set", NULL_PARG);
125 			return (NULL);
126 		}
127 		break;
128 	}
129 	return (m);
130 }
131 
132 #if PIPEC
133 /*
134  * Is a mark letter is invalid?
135  */
136 	public int
137 badmark(c)
138 	int c;
139 {
140 	return (getmark(c) == NULL);
141 }
142 #endif
143 
144 /*
145  * Set a user-defined mark.
146  */
147 	public void
148 setmark(c)
149 	int c;
150 {
151 	register struct mark *m;
152 	struct scrpos scrpos;
153 
154 	m = getumark(c);
155 	if (m == NULL)
156 		return;
157 	get_scrpos(&scrpos);
158 	m->m_scrpos = scrpos;
159 	m->m_ifile = curr_ifile;
160 }
161 
162 /*
163  * Set lmark (the mark named by the apostrophe).
164  */
165 	public void
166 lastmark()
167 {
168 	struct scrpos scrpos;
169 
170 	if (ch_getflags() & CH_HELPFILE)
171 		return;
172 	get_scrpos(&scrpos);
173 	if (scrpos.pos == NULL_POSITION)
174 		return;
175 	marks[LASTMARK].m_scrpos = scrpos;
176 	marks[LASTMARK].m_ifile = curr_ifile;
177 }
178 
179 /*
180  * Go to a mark.
181  */
182 	public void
183 gomark(c)
184 	int c;
185 {
186 	register struct mark *m;
187 	struct scrpos scrpos;
188 
189 	m = getmark(c);
190 	if (m == NULL)
191 		return;
192 
193 	/*
194 	 * If we're trying to go to the lastmark and
195 	 * it has not been set to anything yet,
196 	 * set it to the beginning of the current file.
197 	 */
198 	if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
199 	{
200 		m->m_ifile = curr_ifile;
201 		m->m_scrpos.pos = ch_zero();
202 		m->m_scrpos.ln = jump_sline;
203 	}
204 
205 	/*
206 	 * If we're using lmark, we must save the screen position now,
207 	 * because if we call edit_ifile() below, lmark will change.
208 	 * (We save the screen position even if we're not using lmark.)
209 	 */
210 	scrpos = m->m_scrpos;
211 	if (m->m_ifile != curr_ifile)
212 	{
213 		/*
214 		 * Not in the current file; edit the correct file.
215 		 */
216 		if (edit_ifile(m->m_ifile))
217 			return;
218 	}
219 
220 	jump_loc(scrpos.pos, scrpos.ln);
221 }
222 
223 #if PIPEC
224 /*
225  * Return the position associated with a given mark letter.
226  *
227  * We don't return which screen line the position
228  * is associated with, but this doesn't matter much,
229  * because it's always the first non-blank line on the screen.
230  */
231 	public POSITION
232 markpos(c)
233 	int c;
234 {
235 	register struct mark *m;
236 
237 	m = getmark(c);
238 	if (m == NULL)
239 		return (NULL_POSITION);
240 
241 	if (m->m_ifile != curr_ifile)
242 	{
243 		error("Mark not in current file", NULL_PARG);
244 		return (NULL_POSITION);
245 	}
246 	return (m->m_scrpos.pos);
247 }
248 #endif /* PIPEC */
249 
250 /*
251  * Clear the marks associated with a specified ifile.
252  */
253 	public void
254 unmark(ifile)
255 	IFILE ifile;
256 {
257 	int i;
258 
259 	for (i = 0;  i < NMARKS;  i++)
260 		if (marks[i].m_ifile == ifile)
261 			marks[i].m_scrpos.pos = NULL_POSITION;
262 }
263