db_input.c revision 1.9 
1/*	$NetBSD: db_input.c,v 1.9 1997/11/16 23:51:23 lukem 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
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/param.h>
33#include <sys/proc.h>
34
35#include <machine/db_machdep.h>
36
37#include <ddb/db_output.h>
38#include <ddb/db_command.h>
39#include <ddb/db_sym.h>
40#include <ddb/db_extern.h>
41
42#include <dev/cons.h>
43
44#ifndef DDB_HISTORY_SIZE
45#define DDB_HISTORY_SIZE 0
46#endif /* DDB_HISTORY_SIZE */
47
48/*
49 * Character input and editing.
50 */
51
52/*
53 * We don't track output position while editing input,
54 * since input always ends with a new-line.  We just
55 * reset the line position at the end.
56 */
57char *	db_lbuf_start;	/* start of input line buffer */
58char *	db_lbuf_end;	/* end of input line buffer */
59char *	db_lc;		/* current character */
60char *	db_le;		/* one past last character */
61#if DDB_HISTORY_SIZE != 0
62char    db_history[DDB_HISTORY_SIZE];	/* start of history buffer */
63int     db_history_size = DDB_HISTORY_SIZE;/* size of history buffer */
64char *  db_history_curr = db_history;	/* start of current line */
65char *  db_history_last = db_history;	/* start of last line */
66char *  db_history_prev = (char *) 0;	/* start of previous line */
67#endif
68
69
70#define	CTRL(c)		((c) & 0x1f)
71#define	isspace(c)	((c) == ' ' || (c) == '\t')
72#define	BLANK		' '
73#define	BACKUP		'\b'
74
75static int cnmaygetc __P((void));
76
77void
78db_putstring(s, count)
79	char	*s;
80	int	count;
81{
82	while (--count >= 0)
83	    cnputc(*s++);
84}
85
86void
87db_putnchars(c, count)
88	int	c;
89	int	count;
90{
91	while (--count >= 0)
92	    cnputc(c);
93}
94
95/*
96 * Delete N characters, forward or backward
97 */
98#define	DEL_FWD		0
99#define	DEL_BWD		1
100void
101db_delete(n, bwd)
102	int	n;
103	int	bwd;
104{
105	register char *p;
106
107	if (bwd) {
108	    db_lc -= n;
109	    db_putnchars(BACKUP, n);
110	}
111	for (p = db_lc; p < db_le-n; p++) {
112	    *p = *(p+n);
113	    cnputc(*p);
114	}
115	db_putnchars(BLANK, n);
116	db_putnchars(BACKUP, db_le - db_lc);
117	db_le -= n;
118}
119
120void
121db_delete_line()
122{
123	db_delete(db_le - db_lc, DEL_FWD);
124	db_delete(db_lc - db_lbuf_start, DEL_BWD);
125	db_le = db_lc = db_lbuf_start;
126}
127
128#if DDB_HISTORY_SIZE != 0
129#define INC_DB_CURR() \
130    do { \
131	     db_history_curr++; \
132	     if (db_history_curr > \
133		 db_history + db_history_size - 1) \
134		     db_history_curr = db_history; \
135       } while (0)
136#define DEC_DB_CURR() \
137    do { \
138	     db_history_curr--; \
139	     if (db_history_curr < db_history) \
140		 db_history_curr = db_history + \
141		 db_history_size - 1; \
142       } while (0)
143#endif
144
145/* returns TRUE at end-of-line */
146int
147db_inputchar(c)
148	int	c;
149{
150	switch (c) {
151	    case CTRL('b'):
152		/* back up one character */
153		if (db_lc > db_lbuf_start) {
154		    cnputc(BACKUP);
155		    db_lc--;
156		}
157		break;
158	    case CTRL('f'):
159		/* forward one character */
160		if (db_lc < db_le) {
161		    cnputc(*db_lc);
162		    db_lc++;
163		}
164		break;
165	    case CTRL('a'):
166		/* beginning of line */
167		while (db_lc > db_lbuf_start) {
168		    cnputc(BACKUP);
169		    db_lc--;
170		}
171		break;
172	    case CTRL('e'):
173		/* end of line */
174		while (db_lc < db_le) {
175		    cnputc(*db_lc);
176		    db_lc++;
177		}
178		break;
179	    case CTRL('h'):
180	    case 0177:
181		/* erase previous character */
182		if (db_lc > db_lbuf_start)
183		    db_delete(1, DEL_BWD);
184		break;
185	    case CTRL('d'):
186		/* erase next character */
187		if (db_lc < db_le)
188		    db_delete(1, DEL_FWD);
189		break;
190	    case CTRL('k'):
191		/* delete to end of line */
192		if (db_lc < db_le)
193		    db_delete(db_le - db_lc, DEL_FWD);
194		break;
195	    case CTRL('u'):
196		/* delete line */
197	        db_delete_line();
198		break;
199	    case CTRL('t'):
200		/* twiddle last 2 characters */
201		if (db_lc >= db_lbuf_start + 2) {
202		    c = db_lc[-2];
203		    db_lc[-2] = db_lc[-1];
204		    db_lc[-1] = c;
205		    cnputc(BACKUP);
206		    cnputc(BACKUP);
207		    cnputc(db_lc[-2]);
208		    cnputc(db_lc[-1]);
209		}
210		break;
211#if DDB_HISTORY_SIZE != 0
212	    case CTRL('p'):
213	        DEC_DB_CURR();
214	        while (db_history_curr != db_history_last) {
215			DEC_DB_CURR();
216			if (*db_history_curr == '\0')
217			    break;
218		}
219		db_delete_line();
220		if (db_history_curr == db_history_last) {
221			INC_DB_CURR();
222			db_le = db_lc = db_lbuf_start;
223		} else {
224			register char *p;
225			INC_DB_CURR();
226			for (p = db_history_curr, db_le = db_lbuf_start;
227			     *p; ) {
228				*db_le++ = *p++;
229				if (p == db_history + db_history_size) {
230					p = db_history;
231				}
232			}
233			db_lc = db_le;
234		}
235		db_putstring(db_lbuf_start, db_le - db_lbuf_start);
236		break;
237	    case CTRL('n'):
238	        while (db_history_curr != db_history_last) {
239			if (*db_history_curr == '\0')
240			    break;
241			INC_DB_CURR();
242		}
243		if (db_history_curr != db_history_last) {
244			INC_DB_CURR();
245			db_delete_line();
246			if (db_history_curr != db_history_last) {
247				register char *p;
248				for (p = db_history_curr,
249				     db_le = db_lbuf_start; *p;) {
250					*db_le++ = *p++;
251					if (p == db_history +
252					    db_history_size) {
253						p = db_history;
254					}
255				}
256				db_lc = db_le;
257			}
258			db_putstring(db_lbuf_start, db_le - db_lbuf_start);
259		}
260		break;
261#endif
262	    case CTRL('r'):
263		db_putstring("^R\n", 3);
264		if (db_le > db_lbuf_start) {
265		    db_putstring(db_lbuf_start, db_le - db_lbuf_start);
266		    db_putnchars(BACKUP, db_le - db_lc);
267		}
268		break;
269	    case '\n':
270	    case '\r':
271#if DDB_HISTORY_SIZE != 0
272		/* Check if it same than previous line */
273		if (db_history_curr == db_history_prev) {
274			register char *pp, *pc;
275
276			/* Is it unmodified */
277			for (pp = db_history_prev, pc = db_lbuf_start;
278			     pc != db_le && *pp; pp++, pc++) {
279				if (*pp != *pc)
280				    break;
281				if (++pp == db_history + db_history_size) {
282					pp = db_history;
283				}
284				if (++pc == db_history + db_history_size) {
285					pc = db_history;
286				}
287			}
288			if (!*pp && pc == db_le) {
289				/* Repeted previous line, not saved */
290				db_history_curr = db_history_last;
291				*db_le++ = c;
292				return (TRUE);
293			}
294		}
295		if (db_le != db_lbuf_start) {
296			register char *p;
297			db_history_prev = db_history_last;
298			for (p = db_lbuf_start; p != db_le; p++) {
299				*db_history_last++ = *p;
300				if (db_history_last == db_history +
301				    db_history_size) {
302					db_history_last = db_history;
303				}
304			}
305			*db_history_last++ = '\0';
306		}
307		db_history_curr = db_history_last;
308#endif
309		*db_le++ = c;
310		return (1);
311	    default:
312		if (db_le == db_lbuf_end) {
313		    cnputc('\007');
314		}
315		else if (c >= ' ' && c <= '~') {
316		    register char *p;
317
318		    for (p = db_le; p > db_lc; p--)
319			*p = *(p-1);
320		    *db_lc++ = c;
321		    db_le++;
322		    cnputc(c);
323		    db_putstring(db_lc, db_le - db_lc);
324		    db_putnchars(BACKUP, db_le - db_lc);
325		}
326		break;
327	}
328	return (0);
329}
330
331int
332db_readline(lstart, lsize)
333	char *	lstart;
334	int	lsize;
335{
336	db_force_whitespace();	/* synch output position */
337
338	db_lbuf_start = lstart;
339	db_lbuf_end   = lstart + lsize;
340	db_lc = lstart;
341	db_le = lstart;
342
343	while (!db_inputchar(cngetc()))
344	    continue;
345
346	db_putchar('\n');	/* synch output position */
347
348	*db_le = 0;
349	return (db_le - db_lbuf_start);
350}
351
352void
353db_check_interrupt()
354{
355	register int	c;
356
357	c = cnmaygetc();
358	switch (c) {
359	    case -1:		/* no character */
360		return;
361
362	    case CTRL('c'):
363		db_error((char *)0);
364		/*NOTREACHED*/
365
366	    case CTRL('s'):
367		do {
368		    c = cnmaygetc();
369		    if (c == CTRL('c')) {
370			db_error((char *)0);
371			/*NOTREACHED*/
372		    }
373		} while (c != CTRL('q'));
374		break;
375
376	    default:
377		/* drop on floor */
378		break;
379	}
380}
381
382static int
383cnmaygetc ()
384{
385	return (-1);
386}
387