xref: /minix/external/bsd/less/dist/mark.c (revision 84d9c625)
1 /*	$NetBSD: mark.c,v 1.3 2013/09/04 19:44:21 tron Exp $	*/
2 
3 /*
4  * Copyright (C) 1984-2012  Mark Nudelman
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 #include "less.h"
14 
15 extern IFILE curr_ifile;
16 extern int sc_height;
17 extern int jump_sline;
18 
19 /*
20  * A mark is an ifile (input file) plus a position within the file.
21  */
22 struct mark {
23 	IFILE m_ifile;
24 	struct scrpos m_scrpos;
25 };
26 
27 /*
28  * The table of marks.
29  * Each mark is identified by a lowercase or uppercase letter.
30  * The final one is lmark, for the "last mark"; addressed by the apostrophe.
31  */
32 #define	NMARKS		((2*26)+1)	/* a-z, A-Z, lastmark */
33 #define	LASTMARK	(NMARKS-1)
34 static struct mark marks[NMARKS];
35 
36 /*
37  * Initialize the mark table to show no marks are set.
38  */
39 	public void
init_mark()40 init_mark()
41 {
42 	int i;
43 
44 	for (i = 0;  i < NMARKS;  i++)
45 		marks[i].m_scrpos.pos = NULL_POSITION;
46 }
47 
48 /*
49  * See if a mark letter is valid (between a and z).
50  */
51 	static struct mark *
getumark(c)52 getumark(c)
53 	int c;
54 {
55 	if (c >= 'a' && c <= 'z')
56 		return (&marks[c-'a']);
57 
58 	if (c >= 'A' && c <= 'Z')
59 		return (&marks[c-'A'+26]);
60 
61 	error("Invalid mark letter", NULL_PARG);
62 	return (NULL);
63 }
64 
65 /*
66  * Get the mark structure identified by a character.
67  * The mark struct may come either from the mark table
68  * or may be constructed on the fly for certain characters like ^, $.
69  */
70 	static struct mark *
getmark(c)71 getmark(c)
72 	int c;
73 {
74 	register struct mark *m;
75 	static struct mark sm;
76 
77 	switch (c)
78 	{
79 	case '^':
80 		/*
81 		 * Beginning of the current file.
82 		 */
83 		m = &sm;
84 		m->m_scrpos.pos = ch_zero();
85 		m->m_scrpos.ln = 0;
86 		m->m_ifile = curr_ifile;
87 		break;
88 	case '$':
89 		/*
90 		 * End of the current file.
91 		 */
92 		if (ch_end_seek())
93 		{
94 			error("Cannot seek to end of file", NULL_PARG);
95 			return (NULL);
96 		}
97 		m = &sm;
98 		m->m_scrpos.pos = ch_tell();
99 		m->m_scrpos.ln = sc_height-1;
100 		m->m_ifile = curr_ifile;
101 		break;
102 	case '.':
103 		/*
104 		 * Current position in the current file.
105 		 */
106 		m = &sm;
107 		get_scrpos(&m->m_scrpos);
108 		m->m_ifile = curr_ifile;
109 		break;
110 	case '\'':
111 		/*
112 		 * The "last mark".
113 		 */
114 		m = &marks[LASTMARK];
115 		break;
116 	default:
117 		/*
118 		 * Must be a user-defined mark.
119 		 */
120 		m = getumark(c);
121 		if (m == NULL)
122 			break;
123 		if (m->m_scrpos.pos == NULL_POSITION)
124 		{
125 			error("Mark not set", NULL_PARG);
126 			return (NULL);
127 		}
128 		break;
129 	}
130 	return (m);
131 }
132 
133 /*
134  * Is a mark letter is invalid?
135  */
136 	public int
badmark(c)137 badmark(c)
138 	int c;
139 {
140 	return (getmark(c) == NULL);
141 }
142 
143 /*
144  * Set a user-defined mark.
145  */
146 	public void
setmark(c)147 setmark(c)
148 	int c;
149 {
150 	register struct mark *m;
151 	struct scrpos scrpos;
152 
153 	m = getumark(c);
154 	if (m == NULL)
155 		return;
156 	get_scrpos(&scrpos);
157 	m->m_scrpos = scrpos;
158 	m->m_ifile = curr_ifile;
159 }
160 
161 /*
162  * Set lmark (the mark named by the apostrophe).
163  */
164 	public void
lastmark()165 lastmark()
166 {
167 	struct scrpos scrpos;
168 
169 	if (ch_getflags() & CH_HELPFILE)
170 		return;
171 	get_scrpos(&scrpos);
172 	if (scrpos.pos == NULL_POSITION)
173 		return;
174 	marks[LASTMARK].m_scrpos = scrpos;
175 	marks[LASTMARK].m_ifile = curr_ifile;
176 }
177 
178 /*
179  * Go to a mark.
180  */
181 	public void
gomark(c)182 gomark(c)
183 	int c;
184 {
185 	register struct mark *m;
186 	struct scrpos scrpos;
187 
188 	m = getmark(c);
189 	if (m == NULL)
190 		return;
191 
192 	/*
193 	 * If we're trying to go to the lastmark and
194 	 * it has not been set to anything yet,
195 	 * set it to the beginning of the current file.
196 	 */
197 	if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
198 	{
199 		m->m_ifile = curr_ifile;
200 		m->m_scrpos.pos = ch_zero();
201 		m->m_scrpos.ln = jump_sline;
202 	}
203 
204 	/*
205 	 * If we're using lmark, we must save the screen position now,
206 	 * because if we call edit_ifile() below, lmark will change.
207 	 * (We save the screen position even if we're not using lmark.)
208 	 */
209 	scrpos = m->m_scrpos;
210 	if (m->m_ifile != curr_ifile)
211 	{
212 		/*
213 		 * Not in the current file; edit the correct file.
214 		 */
215 		if (edit_ifile(m->m_ifile))
216 			return;
217 	}
218 
219 	jump_loc(scrpos.pos, scrpos.ln);
220 }
221 
222 /*
223  * Return the position associated with a given mark letter.
224  *
225  * We don't return which screen line the position
226  * is associated with, but this doesn't matter much,
227  * because it's always the first non-blank line on the screen.
228  */
229 	public POSITION
markpos(c)230 markpos(c)
231 	int c;
232 {
233 	register struct mark *m;
234 
235 	m = getmark(c);
236 	if (m == NULL)
237 		return (NULL_POSITION);
238 
239 	if (m->m_ifile != curr_ifile)
240 	{
241 		error("Mark not in current file", NULL_PARG);
242 		return (NULL_POSITION);
243 	}
244 	return (m->m_scrpos.pos);
245 }
246 
247 /*
248  * Clear the marks associated with a specified ifile.
249  */
250 	public void
unmark(ifile)251 unmark(ifile)
252 	IFILE ifile;
253 {
254 	int i;
255 
256 	for (i = 0;  i < NMARKS;  i++)
257 		if (marks[i].m_ifile == ifile)
258 			marks[i].m_scrpos.pos = NULL_POSITION;
259 }
260