FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_input.c
1 /* $NetBSD: db_input.c,v 1.19 2002/11/04 06:24:41 itohy Exp $ */
2
3 /*
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * All Rights Reserved.
7 *
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
27 *
28 * Author: David B. Golub, Carnegie Mellon University
29 * Date: 7/90
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: db_input.c,v 1.19 2002/11/04 06:24:41 itohy Exp $");
34
35 #include "opt_ddbparam.h"
36
37 #include <sys/param.h>
38 #include <sys/proc.h>
39
40 #include <machine/db_machdep.h>
41
42 #include <ddb/db_output.h>
43 #include <ddb/db_command.h>
44 #include <ddb/db_sym.h>
45 #include <ddb/db_extern.h>
46
47 #include <dev/cons.h>
48
49 #ifndef DDB_HISTORY_SIZE
50 #define DDB_HISTORY_SIZE 0
51 #endif /* DDB_HISTORY_SIZE */
52
53 /*
54 * Character input and editing.
55 */
56
57 /*
58 * We don't track output position while editing input,
59 * since input always ends with a new-line. We just
60 * reset the line position at the end.
61 */
62 static char *db_lbuf_start; /* start of input line buffer */
63 static char *db_lbuf_end; /* end of input line buffer */
64 static char *db_lc; /* current character */
65 static char *db_le; /* one past last character */
66 #if DDB_HISTORY_SIZE != 0
67 static char db_history[DDB_HISTORY_SIZE]; /* start of history buffer */
68 static int db_history_size = DDB_HISTORY_SIZE;/* size of history buffer */
69 static char *db_history_curr = db_history; /* start of current line */
70 static char *db_history_last = db_history; /* start of last line */
71 static char *db_history_prev = (char *) 0; /* start of previous line */
72 #endif
73
74
75 #define CTRL(c) ((c) & 0x1f)
76 #define isspace(c) ((c) == ' ' || (c) == '\t')
77 #define BLANK ' '
78 #define BACKUP '\b'
79
80 static int cnmaygetc(void);
81 static void db_putstring(char *, int);
82 static void db_putnchars(int, int);
83 static void db_delete(int, int);
84 static void db_delete_line(void);
85 static int db_inputchar(int);
86
87 static void
88 db_putstring(char *s, int count)
89 {
90
91 while (--count >= 0)
92 cnputc(*s++);
93 }
94
95 static void
96 db_putnchars(int c, int count)
97 {
98
99 while (--count >= 0)
100 cnputc(c);
101 }
102
103 /*
104 * Delete N characters, forward or backward
105 */
106 #define DEL_FWD 0
107 #define DEL_BWD 1
108 static void
109 db_delete(int n, int bwd)
110 {
111 char *p;
112
113 if (bwd) {
114 db_lc -= n;
115 db_putnchars(BACKUP, n);
116 }
117 for (p = db_lc; p < db_le-n; p++) {
118 *p = *(p+n);
119 cnputc(*p);
120 }
121 db_putnchars(BLANK, n);
122 db_putnchars(BACKUP, db_le - db_lc);
123 db_le -= n;
124 }
125
126 static void
127 db_delete_line(void)
128 {
129
130 db_delete(db_le - db_lc, DEL_FWD);
131 db_delete(db_lc - db_lbuf_start, DEL_BWD);
132 db_le = db_lc = db_lbuf_start;
133 }
134
135 #if DDB_HISTORY_SIZE != 0
136 #define INC_DB_CURR() \
137 do { \
138 db_history_curr++; \
139 if (db_history_curr > db_history + db_history_size - 1) \
140 db_history_curr = db_history; \
141 } while (/*CONSTCOND*/ 0)
142 #define DEC_DB_CURR() \
143 do { \
144 db_history_curr--; \
145 if (db_history_curr < db_history) \
146 db_history_curr = db_history + \
147 db_history_size - 1; \
148 } while (/*CONSTCOND*/ 0)
149 #endif
150
151 /* returns TRUE at end-of-line */
152 static int
153 db_inputchar(int c)
154 {
155 switch (c) {
156 case CTRL('b'):
157 /* back up one character */
158 if (db_lc > db_lbuf_start) {
159 cnputc(BACKUP);
160 db_lc--;
161 }
162 break;
163 case CTRL('f'):
164 /* forward one character */
165 if (db_lc < db_le) {
166 cnputc(*db_lc);
167 db_lc++;
168 }
169 break;
170 case CTRL('a'):
171 /* beginning of line */
172 while (db_lc > db_lbuf_start) {
173 cnputc(BACKUP);
174 db_lc--;
175 }
176 break;
177 case CTRL('e'):
178 /* end of line */
179 while (db_lc < db_le) {
180 cnputc(*db_lc);
181 db_lc++;
182 }
183 break;
184 case CTRL('h'):
185 case 0177:
186 /* erase previous character */
187 if (db_lc > db_lbuf_start)
188 db_delete(1, DEL_BWD);
189 break;
190 case CTRL('d'):
191 /* erase next character */
192 if (db_lc < db_le)
193 db_delete(1, DEL_FWD);
194 break;
195 case CTRL('k'):
196 /* delete to end of line */
197 if (db_lc < db_le)
198 db_delete(db_le - db_lc, DEL_FWD);
199 break;
200 case CTRL('u'):
201 /* delete line */
202 db_delete_line();
203 break;
204 case CTRL('t'):
205 /* twiddle last 2 characters */
206 if (db_lc >= db_lbuf_start + 1) {
207 if (db_lc < db_le) {
208 c = db_lc[-1];
209 db_lc[-1] = db_lc[0];
210 db_lc[0] = c;
211 cnputc(BACKUP);
212 cnputc(db_lc[-1]);
213 cnputc(db_lc[0]);
214 db_lc++;
215 } else if (db_lc >= db_lbuf_start + 2) {
216 c = db_lc[-2];
217 db_lc[-2] = db_lc[-1];
218 db_lc[-1] = c;
219 cnputc(BACKUP);
220 cnputc(BACKUP);
221 cnputc(db_lc[-2]);
222 cnputc(db_lc[-1]);
223 }
224 }
225 break;
226 #if DDB_HISTORY_SIZE != 0
227 case CTRL('p'):
228 DEC_DB_CURR();
229 while (db_history_curr != db_history_last) {
230 DEC_DB_CURR();
231 if (*db_history_curr == '\0')
232 break;
233 }
234 db_delete_line();
235 if (db_history_curr == db_history_last) {
236 INC_DB_CURR();
237 db_le = db_lc = db_lbuf_start;
238 } else {
239 char *p;
240 INC_DB_CURR();
241 for (p = db_history_curr, db_le = db_lbuf_start;
242 *p; ) {
243 *db_le++ = *p++;
244 if (p == db_history + db_history_size) {
245 p = db_history;
246 }
247 }
248 db_lc = db_le;
249 }
250 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
251 break;
252 case CTRL('n'):
253 while (db_history_curr != db_history_last) {
254 if (*db_history_curr == '\0')
255 break;
256 INC_DB_CURR();
257 }
258 if (db_history_curr != db_history_last) {
259 INC_DB_CURR();
260 db_delete_line();
261 if (db_history_curr != db_history_last) {
262 char *p;
263 for (p = db_history_curr,
264 db_le = db_lbuf_start; *p;) {
265 *db_le++ = *p++;
266 if (p == db_history +
267 db_history_size) {
268 p = db_history;
269 }
270 }
271 db_lc = db_le;
272 }
273 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
274 }
275 break;
276 #endif
277 case CTRL('r'):
278 db_putstring("^R\n", 3);
279 if (db_le > db_lbuf_start) {
280 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
281 db_putnchars(BACKUP, db_le - db_lc);
282 }
283 break;
284 case '\n':
285 case '\r':
286 #if DDB_HISTORY_SIZE != 0
287 /* Check if it same than previous line */
288 if (db_history_curr == db_history_prev) {
289 char *pp, *pc;
290
291 /* Is it unmodified */
292 for (pp = db_history_prev, pc = db_lbuf_start;
293 pc != db_le && *pp; pp++, pc++) {
294 if (*pp != *pc)
295 break;
296 if (++pp == db_history + db_history_size) {
297 pp = db_history;
298 }
299 if (++pc == db_history + db_history_size) {
300 pc = db_history;
301 }
302 }
303 if (!*pp && pc == db_le) {
304 /* Repeted previous line, not saved */
305 db_history_curr = db_history_last;
306 *db_le++ = c;
307 return (TRUE);
308 }
309 }
310 if (db_le != db_lbuf_start) {
311 char *p;
312 db_history_prev = db_history_last;
313 for (p = db_lbuf_start; p != db_le; p++) {
314 *db_history_last++ = *p;
315 if (db_history_last == db_history +
316 db_history_size) {
317 db_history_last = db_history;
318 }
319 }
320 *db_history_last++ = '\0';
321 }
322 db_history_curr = db_history_last;
323 #endif
324 *db_le++ = c;
325 return (1);
326 default:
327 if (db_le == db_lbuf_end) {
328 cnputc('\007');
329 }
330 else if (c >= ' ' && c <= '~') {
331 char *p;
332
333 for (p = db_le; p > db_lc; p--)
334 *p = *(p-1);
335 *db_lc++ = c;
336 db_le++;
337 cnputc(c);
338 db_putstring(db_lc, db_le - db_lc);
339 db_putnchars(BACKUP, db_le - db_lc);
340 }
341 break;
342 }
343 return (0);
344 }
345
346 int
347 db_readline(char *lstart, int lsize)
348 {
349 db_force_whitespace(); /* synch output position */
350
351 db_lbuf_start = lstart;
352 db_lbuf_end = lstart + lsize;
353 db_lc = lstart;
354 db_le = lstart;
355
356 while (!db_inputchar(cngetc()))
357 continue;
358
359 db_putchar('\n'); /* synch output position */
360
361 *db_le = 0;
362 return (db_le - db_lbuf_start);
363 }
364
365 void
366 db_check_interrupt(void)
367 {
368 int c;
369
370 c = cnmaygetc();
371 switch (c) {
372 case -1: /* no character */
373 return;
374
375 case CTRL('c'):
376 db_error((char *)0);
377 /*NOTREACHED*/
378
379 case CTRL('s'):
380 do {
381 c = cnmaygetc();
382 if (c == CTRL('c')) {
383 db_error((char *)0);
384 /*NOTREACHED*/
385 }
386 } while (c != CTRL('q'));
387 break;
388
389 default:
390 /* drop on floor */
391 break;
392 }
393 }
394
395 static int
396 cnmaygetc(void)
397 {
398
399 return (-1);
400 }
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