xref: /openbsd-src/usr.bin/vi/common/cut.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: cut.c,v 1.10 2006/01/08 21:09:13 miod 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 #ifndef lint
15 static const char sccsid[] = "@(#)cut.c	10.10 (Berkeley) 9/15/96";
16 #endif /* not lint */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 
21 #include <bitstring.h>
22 #include <ctype.h>
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <limits.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 
30 #include "common.h"
31 
32 static void	cb_rotate(SCR *);
33 
34 /*
35  * cut --
36  *	Put a range of lines/columns into a TEXT buffer.
37  *
38  * There are two buffer areas, both found in the global structure.  The first
39  * is the linked list of all the buffers the user has named, the second is the
40  * unnamed buffer storage.  There is a pointer, too, which is the current
41  * default buffer, i.e. it may point to the unnamed buffer or a named buffer
42  * depending on into what buffer the last text was cut.  Logically, in both
43  * delete and yank operations, if the user names a buffer, the text is cut
44  * into it.  If it's a delete of information on more than a single line, the
45  * contents of the numbered buffers are rotated up one, the contents of the
46  * buffer named '9' are discarded, and the text is cut into the buffer named
47  * '1'.  The text is always cut into the unnamed buffer.
48  *
49  * In all cases, upper-case buffer names are the same as lower-case names,
50  * with the exception that they cause the buffer to be appended to instead
51  * of replaced.  Note, however, that if text is appended to a buffer, the
52  * default buffer only contains the appended text, not the entire contents
53  * of the buffer.
54  *
55  * !!!
56  * The contents of the default buffer would disappear after most operations
57  * in historic vi.  It's unclear that this is useful, so we don't bother.
58  *
59  * When users explicitly cut text into the numeric buffers, historic vi became
60  * genuinely strange.  I've never been able to figure out what was supposed to
61  * happen.  It behaved differently if you deleted text than if you yanked text,
62  * and, in the latter case, the text was appended to the buffer instead of
63  * replacing the contents.  Hopefully it's not worth getting right, and here
64  * we just treat the numeric buffers like any other named buffer.
65  *
66  * PUBLIC: int cut(SCR *, CHAR_T *, MARK *, MARK *, int);
67  */
68 int
69 cut(sp, namep, fm, tm, flags)
70 	SCR *sp;
71 	CHAR_T *namep;
72 	MARK *fm, *tm;
73 	int flags;
74 {
75 	CB *cbp;
76 	CHAR_T name = '1';	/* default numeric buffer */
77 	recno_t lno;
78 	int append, copy_one, copy_def;
79 
80 	/*
81 	 * If the user specified a buffer, put it there.  (This may require
82 	 * a copy into the numeric buffers.  We do the copy so that we don't
83 	 * have to reference count and so we don't have to deal with things
84 	 * like appends to buffers that are used multiple times.)
85 	 *
86 	 * Otherwise, if it's supposed to be put in a numeric buffer (usually
87 	 * a delete) put it there.  The rules for putting things in numeric
88 	 * buffers were historically a little strange.  There were three cases.
89 	 *
90 	 *	1: Some motions are always line mode motions, which means
91 	 *	   that the cut always goes into the numeric buffers.
92 	 *	2: Some motions aren't line mode motions, e.g. d10w, but
93 	 *	   can cross line boundaries.  For these commands, if the
94 	 *	   cut crosses a line boundary, it goes into the numeric
95 	 *	   buffers.  This includes most of the commands.
96 	 *	3: Some motions aren't line mode motions, e.g. d`<char>,
97 	 *	   but always go into the numeric buffers, regardless.  This
98 	 *	   was the commands: % ` / ? ( ) N n { } -- and nvi adds ^A.
99 	 *
100 	 * Otherwise, put it in the unnamed buffer.
101 	 */
102 	append = copy_one = copy_def = 0;
103 	if (namep != NULL) {
104 		name = *namep;
105 		if (LF_ISSET(CUT_NUMREQ) || (LF_ISSET(CUT_NUMOPT) &&
106 		    (LF_ISSET(CUT_LINEMODE) || fm->lno != tm->lno))) {
107 			copy_one = 1;
108 			cb_rotate(sp);
109 		}
110 		if ((append = isupper(name)) == 1) {
111 			if (!copy_one)
112 				copy_def = 1;
113 			name = tolower(name);
114 		}
115 namecb:		CBNAME(sp, cbp, name);
116 	} else if (LF_ISSET(CUT_NUMREQ) || (LF_ISSET(CUT_NUMOPT) &&
117 	    (LF_ISSET(CUT_LINEMODE) || fm->lno != tm->lno))) {
118 		/* Copy into numeric buffer 1. */
119 		cb_rotate(sp);
120 		goto namecb;
121 	} else
122 		cbp = &sp->gp->dcb_store;
123 
124 copyloop:
125 	/*
126 	 * If this is a new buffer, create it and add it into the list.
127 	 * Otherwise, if it's not an append, free its current contents.
128 	 */
129 	if (cbp == NULL) {
130 		CALLOC_RET(sp, cbp, CB *, 1, sizeof(CB));
131 		cbp->name = name;
132 		CIRCLEQ_INIT(&cbp->textq);
133 		LIST_INSERT_HEAD(&sp->gp->cutq, cbp, q);
134 	} else if (!append) {
135 		text_lfree(&cbp->textq);
136 		cbp->len = 0;
137 		cbp->flags = 0;
138 	}
139 
140 
141 	/* In line mode, it's pretty easy, just cut the lines. */
142 	if (LF_ISSET(CUT_LINEMODE)) {
143 		cbp->flags |= CB_LMODE;
144 		for (lno = fm->lno; lno <= tm->lno; ++lno)
145 			if (cut_line(sp, lno, 0, CUT_LINE_TO_EOL, cbp))
146 				goto cut_line_err;
147 	} else {
148 		/*
149 		 * Get the first line.  A length of CUT_LINE_TO_EOL causes
150 		 * cut_line() to cut from the MARK to the end of the line.
151 		 */
152 		if (cut_line(sp, fm->lno, fm->cno, fm->lno != tm->lno ?
153 		    CUT_LINE_TO_EOL : (tm->cno - fm->cno) + 1, cbp))
154 			goto cut_line_err;
155 
156 		/* Get the intermediate lines. */
157 		for (lno = fm->lno; ++lno < tm->lno;)
158 			if (cut_line(sp, lno, 0, CUT_LINE_TO_EOL, cbp))
159 				goto cut_line_err;
160 
161 		/* Get the last line. */
162 		if (tm->lno != fm->lno &&
163 		    cut_line(sp, lno, 0, tm->cno + 1, cbp))
164 			goto cut_line_err;
165 	}
166 
167 	append = 0;		/* Only append to the named buffer. */
168 	sp->gp->dcbp = cbp;	/* Repoint the default buffer on each pass. */
169 
170 	if (copy_one) {		/* Copy into numeric buffer 1. */
171 		CBNAME(sp, cbp, name);
172 		copy_one = 0;
173 		goto copyloop;
174 	}
175 	if (copy_def) {		/* Copy into the default buffer. */
176 		cbp = &sp->gp->dcb_store;
177 		copy_def = 0;
178 		goto copyloop;
179 	}
180 	return (0);
181 
182 cut_line_err:
183 	text_lfree(&cbp->textq);
184 	cbp->len = 0;
185 	cbp->flags = 0;
186 	return (1);
187 }
188 
189 /*
190  * cb_rotate --
191  *	Rotate the numbered buffers up one.
192  */
193 static void
194 cb_rotate(sp)
195 	SCR *sp;
196 {
197 	CB *cbp, *del_cbp;
198 
199 	del_cbp = NULL;
200 	LIST_FOREACH(cbp, &sp->gp->cutq, q)
201 		switch(cbp->name) {
202 		case '1':
203 			cbp->name = '2';
204 			break;
205 		case '2':
206 			cbp->name = '3';
207 			break;
208 		case '3':
209 			cbp->name = '4';
210 			break;
211 		case '4':
212 			cbp->name = '5';
213 			break;
214 		case '5':
215 			cbp->name = '6';
216 			break;
217 		case '6':
218 			cbp->name = '7';
219 			break;
220 		case '7':
221 			cbp->name = '8';
222 			break;
223 		case '8':
224 			cbp->name = '9';
225 			break;
226 		case '9':
227 			del_cbp = cbp;
228 			break;
229 		}
230 	if (del_cbp != NULL) {
231 		LIST_REMOVE(del_cbp, q);
232 		text_lfree(&del_cbp->textq);
233 		free(del_cbp);
234 	}
235 }
236 
237 /*
238  * cut_line --
239  *	Cut a portion of a single line.
240  *
241  * PUBLIC: int cut_line(SCR *, recno_t, size_t, size_t, CB *);
242  */
243 int
244 cut_line(sp, lno, fcno, clen, cbp)
245 	SCR *sp;
246 	recno_t lno;
247 	size_t fcno, clen;
248 	CB *cbp;
249 {
250 	TEXT *tp;
251 	size_t len;
252 	char *p;
253 
254 	/* Get the line. */
255 	if (db_get(sp, lno, DBG_FATAL, &p, &len))
256 		return (1);
257 
258 	/* Create a TEXT structure that can hold the entire line. */
259 	if ((tp = text_init(sp, NULL, 0, len)) == NULL)
260 		return (1);
261 
262 	/*
263 	 * If the line isn't empty and it's not the entire line,
264 	 * copy the portion we want, and reset the TEXT length.
265 	 */
266 	if (len != 0) {
267 		if (clen == CUT_LINE_TO_EOL)
268 			clen = len - fcno;
269 		memcpy(tp->lb, p + fcno, clen);
270 		tp->len = clen;
271 	}
272 
273 	/* Append to the end of the cut buffer. */
274 	CIRCLEQ_INSERT_TAIL(&cbp->textq, tp, q);
275 	cbp->len += tp->len;
276 
277 	return (0);
278 }
279 
280 /*
281  * cut_close --
282  *	Discard all cut buffers.
283  *
284  * PUBLIC: void cut_close(GS *);
285  */
286 void
287 cut_close(gp)
288 	GS *gp;
289 {
290 	CB *cbp;
291 
292 	/* Free cut buffer list. */
293 	while ((cbp = LIST_FIRST(&gp->cutq)) != NULL) {
294 		if (CIRCLEQ_FIRST(&cbp->textq) != CIRCLEQ_END(&cbp->textq))
295 			text_lfree(&cbp->textq);
296 		LIST_REMOVE(cbp, q);
297 		free(cbp);
298 	}
299 
300 	/* Free default cut storage. */
301 	cbp = &gp->dcb_store;
302 	if (CIRCLEQ_FIRST(&cbp->textq) != CIRCLEQ_END(&cbp->textq))
303 		text_lfree(&cbp->textq);
304 }
305 
306 /*
307  * text_init --
308  *	Allocate a new TEXT structure.
309  *
310  * PUBLIC: TEXT *text_init(SCR *, const char *, size_t, size_t);
311  */
312 TEXT *
313 text_init(sp, p, len, total_len)
314 	SCR *sp;
315 	const char *p;
316 	size_t len, total_len;
317 {
318 	TEXT *tp;
319 
320 	CALLOC(sp, tp, TEXT *, 1, sizeof(TEXT));
321 	if (tp == NULL)
322 		return (NULL);
323 	/* ANSI C doesn't define a call to malloc(3) for 0 bytes. */
324 	if ((tp->lb_len = total_len) != 0) {
325 		MALLOC(sp, tp->lb, CHAR_T *, tp->lb_len);
326 		if (tp->lb == NULL) {
327 			free(tp);
328 			return (NULL);
329 		}
330 		if (p != NULL && len != 0)
331 			memcpy(tp->lb, p, len);
332 	}
333 	tp->len = len;
334 	return (tp);
335 }
336 
337 /*
338  * text_lfree --
339  *	Free a chain of text structures.
340  *
341  * PUBLIC: void text_lfree(TEXTH *);
342  */
343 void
344 text_lfree(headp)
345 	TEXTH *headp;
346 {
347 	TEXT *tp;
348 
349 	while ((tp = CIRCLEQ_FIRST(headp)) != CIRCLEQ_END(headp)) {
350 		CIRCLEQ_REMOVE(headp, tp, q);
351 		text_free(tp);
352 	}
353 }
354 
355 /*
356  * text_free --
357  *	Free a text structure.
358  *
359  * PUBLIC: void text_free(TEXT *);
360  */
361 void
362 text_free(tp)
363 	TEXT *tp;
364 {
365 	if (tp->lb != NULL)
366 		free(tp->lb);
367 	free(tp);
368 }
369