xref: /openbsd/usr.bin/vi/common/cut.c (revision a0242ada)
1 /*	$OpenBSD: cut.c,v 1.17 2017/04/18 01:45:35 deraadt 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 
17 #include <bitstring.h>
18 #include <ctype.h>
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <limits.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
26 #include "common.h"
27 
28 static void	cb_rotate(SCR *);
29 
30 /*
31  * cut --
32  *	Put a range of lines/columns into a TEXT buffer.
33  *
34  * There are two buffer areas, both found in the global structure.  The first
35  * is the linked list of all the buffers the user has named, the second is the
36  * unnamed buffer storage.  There is a pointer, too, which is the current
37  * default buffer, i.e. it may point to the unnamed buffer or a named buffer
38  * depending on into what buffer the last text was cut.  Logically, in both
39  * delete and yank operations, if the user names a buffer, the text is cut
40  * into it.  If it's a delete of information on more than a single line, the
41  * contents of the numbered buffers are rotated up one, the contents of the
42  * buffer named '9' are discarded, and the text is cut into the buffer named
43  * '1'.  The text is always cut into the unnamed buffer.
44  *
45  * In all cases, upper-case buffer names are the same as lower-case names,
46  * with the exception that they cause the buffer to be appended to instead
47  * of replaced.  Note, however, that if text is appended to a buffer, the
48  * default buffer only contains the appended text, not the entire contents
49  * of the buffer.
50  *
51  * !!!
52  * The contents of the default buffer would disappear after most operations
53  * in historic vi.  It's unclear that this is useful, so we don't bother.
54  *
55  * When users explicitly cut text into the numeric buffers, historic vi became
56  * genuinely strange.  I've never been able to figure out what was supposed to
57  * happen.  It behaved differently if you deleted text than if you yanked text,
58  * and, in the latter case, the text was appended to the buffer instead of
59  * replacing the contents.  Hopefully it's not worth getting right, and here
60  * we just treat the numeric buffers like any other named buffer.
61  *
62  * PUBLIC: int cut(SCR *, CHAR_T *, MARK *, MARK *, int);
63  */
64 int
cut(SCR * sp,CHAR_T * namep,MARK * fm,MARK * tm,int flags)65 cut(SCR *sp, CHAR_T *namep, MARK *fm, MARK *tm, int flags)
66 {
67 	CB *cbp;
68 	CHAR_T name = '1';	/* default numeric buffer */
69 	recno_t lno;
70 	int append, copy_one, copy_def;
71 
72 	/*
73 	 * If the user specified a buffer, put it there.  (This may require
74 	 * a copy into the numeric buffers.  We do the copy so that we don't
75 	 * have to reference count and so we don't have to deal with things
76 	 * like appends to buffers that are used multiple times.)
77 	 *
78 	 * Otherwise, if it's supposed to be put in a numeric buffer (usually
79 	 * a delete) put it there.  The rules for putting things in numeric
80 	 * buffers were historically a little strange.  There were three cases.
81 	 *
82 	 *	1: Some motions are always line mode motions, which means
83 	 *	   that the cut always goes into the numeric buffers.
84 	 *	2: Some motions aren't line mode motions, e.g. d10w, but
85 	 *	   can cross line boundaries.  For these commands, if the
86 	 *	   cut crosses a line boundary, it goes into the numeric
87 	 *	   buffers.  This includes most of the commands.
88 	 *	3: Some motions aren't line mode motions, e.g. d`<char>,
89 	 *	   but always go into the numeric buffers, regardless.  This
90 	 *	   was the commands: % ` / ? ( ) N n { } -- and nvi adds ^A.
91 	 *
92 	 * Otherwise, put it in the unnamed buffer.
93 	 */
94 	append = copy_one = copy_def = 0;
95 	if (namep != NULL) {
96 		name = *namep;
97 		if (LF_ISSET(CUT_NUMREQ) || (LF_ISSET(CUT_NUMOPT) &&
98 		    (LF_ISSET(CUT_LINEMODE) || fm->lno != tm->lno))) {
99 			copy_one = 1;
100 			cb_rotate(sp);
101 		}
102 		if ((append = isupper(name)) == 1) {
103 			if (!copy_one)
104 				copy_def = 1;
105 			name = tolower(name);
106 		}
107 namecb:		CBNAME(sp, cbp, name);
108 	} else if (LF_ISSET(CUT_NUMREQ) || (LF_ISSET(CUT_NUMOPT) &&
109 	    (LF_ISSET(CUT_LINEMODE) || fm->lno != tm->lno))) {
110 		/* Copy into numeric buffer 1. */
111 		cb_rotate(sp);
112 		goto namecb;
113 	} else
114 		cbp = &sp->gp->dcb_store;
115 
116 copyloop:
117 	/*
118 	 * If this is a new buffer, create it and add it into the list.
119 	 * Otherwise, if it's not an append, free its current contents.
120 	 */
121 	if (cbp == NULL) {
122 		CALLOC_RET(sp, cbp, 1, sizeof(CB));
123 		cbp->name = name;
124 		TAILQ_INIT(&cbp->textq);
125 		LIST_INSERT_HEAD(&sp->gp->cutq, cbp, q);
126 	} else if (!append) {
127 		text_lfree(&cbp->textq);
128 		cbp->len = 0;
129 		cbp->flags = 0;
130 	}
131 
132 
133 	/* In line mode, it's pretty easy, just cut the lines. */
134 	if (LF_ISSET(CUT_LINEMODE)) {
135 		cbp->flags |= CB_LMODE;
136 		for (lno = fm->lno; lno <= tm->lno; ++lno)
137 			if (cut_line(sp, lno, 0, CUT_LINE_TO_EOL, cbp))
138 				goto cut_line_err;
139 	} else {
140 		/*
141 		 * Get the first line.  A length of CUT_LINE_TO_EOL causes
142 		 * cut_line() to cut from the MARK to the end of the line.
143 		 */
144 		if (cut_line(sp, fm->lno, fm->cno, fm->lno != tm->lno ?
145 		    CUT_LINE_TO_EOL : (tm->cno - fm->cno) + 1, cbp))
146 			goto cut_line_err;
147 
148 		/* Get the intermediate lines. */
149 		for (lno = fm->lno; ++lno < tm->lno;)
150 			if (cut_line(sp, lno, 0, CUT_LINE_TO_EOL, cbp))
151 				goto cut_line_err;
152 
153 		/* Get the last line. */
154 		if (tm->lno != fm->lno &&
155 		    cut_line(sp, lno, 0, tm->cno + 1, cbp))
156 			goto cut_line_err;
157 	}
158 
159 	append = 0;		/* Only append to the named buffer. */
160 	sp->gp->dcbp = cbp;	/* Repoint the default buffer on each pass. */
161 
162 	if (copy_one) {		/* Copy into numeric buffer 1. */
163 		CBNAME(sp, cbp, name);
164 		copy_one = 0;
165 		goto copyloop;
166 	}
167 	if (copy_def) {		/* Copy into the default buffer. */
168 		cbp = &sp->gp->dcb_store;
169 		copy_def = 0;
170 		goto copyloop;
171 	}
172 	return (0);
173 
174 cut_line_err:
175 	text_lfree(&cbp->textq);
176 	cbp->len = 0;
177 	cbp->flags = 0;
178 	return (1);
179 }
180 
181 /*
182  * cb_rotate --
183  *	Rotate the numbered buffers up one.
184  */
185 static void
cb_rotate(SCR * sp)186 cb_rotate(SCR *sp)
187 {
188 	CB *cbp, *del_cbp;
189 
190 	del_cbp = NULL;
191 	LIST_FOREACH(cbp, &sp->gp->cutq, q)
192 		switch(cbp->name) {
193 		case '1':
194 			cbp->name = '2';
195 			break;
196 		case '2':
197 			cbp->name = '3';
198 			break;
199 		case '3':
200 			cbp->name = '4';
201 			break;
202 		case '4':
203 			cbp->name = '5';
204 			break;
205 		case '5':
206 			cbp->name = '6';
207 			break;
208 		case '6':
209 			cbp->name = '7';
210 			break;
211 		case '7':
212 			cbp->name = '8';
213 			break;
214 		case '8':
215 			cbp->name = '9';
216 			break;
217 		case '9':
218 			del_cbp = cbp;
219 			break;
220 		}
221 	if (del_cbp != NULL) {
222 		LIST_REMOVE(del_cbp, q);
223 		text_lfree(&del_cbp->textq);
224 		free(del_cbp);
225 	}
226 }
227 
228 /*
229  * cut_line --
230  *	Cut a portion of a single line.
231  *
232  * PUBLIC: int cut_line(SCR *, recno_t, size_t, size_t, CB *);
233  */
234 int
cut_line(SCR * sp,recno_t lno,size_t fcno,size_t clen,CB * cbp)235 cut_line(SCR *sp, recno_t lno, size_t fcno, size_t clen, CB *cbp)
236 {
237 	TEXT *tp;
238 	size_t len;
239 	char *p;
240 
241 	/* Get the line. */
242 	if (db_get(sp, lno, DBG_FATAL, &p, &len))
243 		return (1);
244 
245 	/* Create a TEXT structure that can hold the entire line. */
246 	if ((tp = text_init(sp, NULL, 0, len)) == NULL)
247 		return (1);
248 
249 	/*
250 	 * If the line isn't empty and it's not the entire line,
251 	 * copy the portion we want, and reset the TEXT length.
252 	 */
253 	if (len != 0) {
254 		if (clen == CUT_LINE_TO_EOL)
255 			clen = len - fcno;
256 		memcpy(tp->lb, p + fcno, clen);
257 		tp->len = clen;
258 	}
259 
260 	/* Append to the end of the cut buffer. */
261 	TAILQ_INSERT_TAIL(&cbp->textq, tp, q);
262 	cbp->len += tp->len;
263 
264 	return (0);
265 }
266 
267 /*
268  * cut_close --
269  *	Discard all cut buffers.
270  *
271  * PUBLIC: void cut_close(GS *);
272  */
273 void
cut_close(GS * gp)274 cut_close(GS *gp)
275 {
276 	CB *cbp;
277 
278 	/* Free cut buffer list. */
279 	while ((cbp = LIST_FIRST(&gp->cutq)) != NULL) {
280 		if (!TAILQ_EMPTY(&cbp->textq))
281 			text_lfree(&cbp->textq);
282 		LIST_REMOVE(cbp, q);
283 		free(cbp);
284 	}
285 
286 	/* Free default cut storage. */
287 	cbp = &gp->dcb_store;
288 	if (!TAILQ_EMPTY(&cbp->textq))
289 		text_lfree(&cbp->textq);
290 }
291 
292 /*
293  * text_init --
294  *	Allocate a new TEXT structure.
295  *
296  * PUBLIC: TEXT *text_init(SCR *, const char *, size_t, size_t);
297  */
298 TEXT *
text_init(SCR * sp,const char * p,size_t len,size_t total_len)299 text_init(SCR *sp, const char *p, size_t len, size_t total_len)
300 {
301 	TEXT *tp;
302 
303 	CALLOC(sp, tp, 1, sizeof(TEXT));
304 	if (tp == NULL)
305 		return (NULL);
306 	/* ANSI C doesn't define a call to malloc(3) for 0 bytes. */
307 	if ((tp->lb_len = total_len) != 0) {
308 		MALLOC(sp, tp->lb, tp->lb_len);
309 		if (tp->lb == NULL) {
310 			free(tp);
311 			return (NULL);
312 		}
313 		if (p != NULL && len != 0)
314 			memcpy(tp->lb, p, len);
315 	}
316 	tp->len = len;
317 	return (tp);
318 }
319 
320 /*
321  * text_lfree --
322  *	Free a chain of text structures.
323  *
324  * PUBLIC: void text_lfree(TEXTH *);
325  */
326 void
text_lfree(TEXTH * headp)327 text_lfree(TEXTH *headp)
328 {
329 	TEXT *tp;
330 
331 	while ((tp = TAILQ_FIRST(headp))) {
332 		TAILQ_REMOVE(headp, tp, q);
333 		text_free(tp);
334 	}
335 }
336 
337 /*
338  * text_free --
339  *	Free a text structure.
340  *
341  * PUBLIC: void text_free(TEXT *);
342  */
343 void
text_free(TEXT * tp)344 text_free(TEXT *tp)
345 {
346 	free(tp->lb);
347 	free(tp);
348 }
349