1 /* $OpenBSD: db_input.c,v 1.19 2020/10/15 03:14:00 deraadt Exp $ */
2 /* $NetBSD: db_input.c,v 1.7 1996/02/05 01:57:02 christos Exp $ */
3
4 /*
5 * Mach Operating System
6 * Copyright (c) 1993,1992,1991,1990 Carnegie Mellon University
7 * All Rights Reserved.
8 *
9 * Permission to use, copy, modify and distribute this software and its
10 * documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation.
14 *
15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
17 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 *
19 * Carnegie Mellon requests users of this software to return to
20 *
21 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
22 * School of Computer Science
23 * Carnegie Mellon University
24 * Pittsburgh PA 15213-3890
25 *
26 * any improvements or extensions that they make and grant Carnegie Mellon
27 * the rights to redistribute these changes.
28 *
29 * Author: David B. Golub, Carnegie Mellon University
30 * Date: 7/90
31 */
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35
36 #include <machine/db_machdep.h>
37
38 #include <ddb/db_var.h>
39 #include <ddb/db_output.h>
40 #include <ddb/db_sym.h>
41 #include <ddb/db_extern.h>
42
43 #include <dev/cons.h>
44
45 /*
46 * Character input and editing.
47 */
48
49 void db_putstring(char *, int);
50 void db_putnchars(int, int);
51 void db_delete(int, int);
52 void db_delete_line(void);
53 int db_inputchar(int);
54
55 /*
56 * We don't track output position while editing input,
57 * since input always ends with a new-line. We just
58 * reset the line position at the end.
59 */
60 char * db_lbuf_start; /* start of input line buffer */
61 char * db_lbuf_end; /* end of input line buffer */
62 char * db_lc; /* current character */
63 char * db_le; /* one past last character */
64 #if DB_HISTORY_SIZE != 0
65 char db_history[DB_HISTORY_SIZE]; /* start of history buffer */
66 int db_history_size = DB_HISTORY_SIZE;/* size of history buffer */
67 char * db_history_curr = db_history; /* start of current line */
68 char * db_history_last = db_history; /* start of last line */
69 char * db_history_prev = (char *) 0; /* start of previous line */
70 #endif
71
72
73 #define CTRL(c) ((c) & 0x1f)
74 #define isspace(c) ((c) == ' ' || (c) == '\t')
75 #define BLANK ' '
76 #define BACKUP '\b'
77
78 void
db_putstring(char * s,int count)79 db_putstring(char *s, int count)
80 {
81 while (--count >= 0)
82 cnputc(*s++);
83 }
84
85 void
db_putnchars(int c,int count)86 db_putnchars(int c, int count)
87 {
88 while (--count >= 0)
89 cnputc(c);
90 }
91
92 /*
93 * Delete N characters, forward or backward
94 */
95 #define DEL_FWD 0
96 #define DEL_BWD 1
97 void
db_delete(int n,int bwd)98 db_delete(int n, int bwd)
99 {
100 char *p;
101
102 if (bwd) {
103 db_lc -= n;
104 db_putnchars(BACKUP, n);
105 }
106 for (p = db_lc; p < db_le-n; p++) {
107 *p = *(p+n);
108 cnputc(*p);
109 }
110 db_putnchars(BLANK, n);
111 db_putnchars(BACKUP, db_le - db_lc);
112 db_le -= n;
113 }
114
115 void
db_delete_line(void)116 db_delete_line(void)
117 {
118 db_delete(db_le - db_lc, DEL_FWD);
119 db_delete(db_lc - db_lbuf_start, DEL_BWD);
120 db_le = db_lc = db_lbuf_start;
121 }
122
123 #if DB_HISTORY_SIZE != 0
124 #define INC_DB_CURR() \
125 do { \
126 db_history_curr++; \
127 if (db_history_curr > \
128 db_history + db_history_size - 1) \
129 db_history_curr = db_history; \
130 } while (0)
131 #define DEC_DB_CURR() \
132 do { \
133 db_history_curr--; \
134 if (db_history_curr < db_history) \
135 db_history_curr = db_history + \
136 db_history_size - 1; \
137 } while (0)
138 #endif
139
140 /* returns `1' at end-of-line */
141 int
db_inputchar(int c)142 db_inputchar(int c)
143 {
144 switch (c) {
145 case CTRL('b'):
146 /* back up one character */
147 if (db_lc > db_lbuf_start) {
148 cnputc(BACKUP);
149 db_lc--;
150 }
151 break;
152 case CTRL('f'):
153 /* forward one character */
154 if (db_lc < db_le) {
155 cnputc(*db_lc);
156 db_lc++;
157 }
158 break;
159 case CTRL('a'):
160 /* beginning of line */
161 while (db_lc > db_lbuf_start) {
162 cnputc(BACKUP);
163 db_lc--;
164 }
165 break;
166 case CTRL('e'):
167 /* end of line */
168 while (db_lc < db_le) {
169 cnputc(*db_lc);
170 db_lc++;
171 }
172 break;
173 case CTRL('w'):
174 /* erase word back */
175 while (db_lc > db_lbuf_start && db_lc[-1] != BLANK)
176 db_delete(1, DEL_BWD);
177 break;
178 case CTRL('h'):
179 case 0177:
180 /* erase previous character */
181 if (db_lc > db_lbuf_start)
182 db_delete(1, DEL_BWD);
183 break;
184 case CTRL('d'):
185 /* erase next character */
186 if (db_lc < db_le)
187 db_delete(1, DEL_FWD);
188 break;
189 case CTRL('k'):
190 /* delete to end of line */
191 if (db_lc < db_le)
192 db_delete(db_le - db_lc, DEL_FWD);
193 break;
194 case CTRL('u'):
195 /* delete line */
196 db_delete_line();
197 break;
198 case CTRL('t'):
199 /* twiddle last 2 characters */
200 if (db_lc >= db_lbuf_start + 2) {
201 c = db_lc[-2];
202 db_lc[-2] = db_lc[-1];
203 db_lc[-1] = c;
204 cnputc(BACKUP);
205 cnputc(BACKUP);
206 cnputc(db_lc[-2]);
207 cnputc(db_lc[-1]);
208 }
209 break;
210 #if DB_HISTORY_SIZE != 0
211 case CTRL('p'):
212 DEC_DB_CURR();
213 while (db_history_curr != db_history_last) {
214 DEC_DB_CURR();
215 if (*db_history_curr == '\0')
216 break;
217 }
218 db_delete_line();
219 if (db_history_curr == db_history_last) {
220 INC_DB_CURR();
221 db_le = db_lc = db_lbuf_start;
222 } else {
223 char *p;
224 INC_DB_CURR();
225 for (p = db_history_curr,
226 db_le = db_lbuf_start;*p; ) {
227 *db_le++ = *p++;
228 if (p == db_history + db_history_size)
229 p = db_history;
230 }
231 db_lc = db_le;
232 }
233 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
234 break;
235 case CTRL('n'):
236 while (db_history_curr != db_history_last) {
237 if (*db_history_curr == '\0')
238 break;
239 INC_DB_CURR();
240 }
241 if (db_history_curr != db_history_last) {
242 INC_DB_CURR();
243 db_delete_line();
244 if (db_history_curr != db_history_last) {
245 char *p;
246 for (p = db_history_curr,
247 db_le = db_lbuf_start; *p;) {
248 *db_le++ = *p++;
249 if (p == db_history + db_history_size)
250 p = db_history;
251 }
252 db_lc = db_le;
253 }
254 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
255 }
256 break;
257 #endif
258 case CTRL('r'):
259 db_putstring("^R\n", 3);
260 if (db_le > db_lbuf_start) {
261 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
262 db_putnchars(BACKUP, db_le - db_lc);
263 }
264 break;
265 case '\n':
266 case '\r':
267 #if DB_HISTORY_SIZE != 0
268 /*
269 * Check whether current line is the same
270 * as previous saved line. If it is, don`t
271 * save it.
272 */
273 if (db_history_curr == db_history_prev) {
274 char *pp, *pc;
275
276 /*
277 * Is it the same?
278 */
279 for (pp = db_history_prev, pc = db_lbuf_start;
280 pc != db_le && *pp; ) {
281 if (*pp != *pc)
282 break;
283 if (++pp == db_history + db_history_size)
284 pp = db_history;
285 pc++;
286 }
287 if (!*pp && pc == db_le) {
288 /*
289 * Repeated previous line. Don`t save.
290 */
291 db_history_curr = db_history_last;
292 *db_le++ = c;
293 return 1;
294 }
295 }
296 if (db_le != db_lbuf_start) {
297 char *p;
298 db_history_prev = db_history_last;
299 for (p = db_lbuf_start; p != db_le; p++) {
300 *db_history_last++ = *p;
301 if (db_history_last ==
302 db_history + db_history_size)
303 db_history_last = db_history;
304 }
305 *db_history_last++ = '\0';
306 if (db_history_last == db_history + db_history_size)
307 db_history_last = db_history;
308 }
309 db_history_curr = db_history_last;
310 #endif
311 *db_le++ = c;
312 return 1;
313 default:
314 if (db_le == db_lbuf_end) {
315 cnputc('\007');
316 } else if (c >= ' ' && c <= '~') {
317 char *p;
318
319 for (p = db_le; p > db_lc; p--)
320 *p = *(p-1);
321 *db_lc++ = c;
322 db_le++;
323 cnputc(c);
324 db_putstring(db_lc, db_le - db_lc);
325 db_putnchars(BACKUP, db_le - db_lc);
326 }
327 break;
328 }
329 return 0;
330 }
331
332 int
db_readline(char * lstart,int lsize)333 db_readline(char *lstart, int lsize)
334 {
335 db_force_whitespace(); /* synch output position */
336
337 db_lbuf_start = lstart;
338 db_lbuf_end = lstart + lsize - 1;
339 db_lc = lstart;
340 db_le = lstart;
341
342 while (!db_inputchar(cngetc()))
343 continue;
344
345 db_putchar('\n'); /* synch output position */
346
347 *db_le = 0;
348 return (db_le - db_lbuf_start);
349 }
350