db_input.c revision 1.10 
1/*	$NetBSD: db_input.c,v 1.10 1998/07/04 22:18:48 jonathan 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 "opt_ddbparam.h"
33
34#include <sys/param.h>
35#include <sys/proc.h>
36
37#include <machine/db_machdep.h>
38
39#include <ddb/db_output.h>
40#include <ddb/db_command.h>
41#include <ddb/db_sym.h>
42#include <ddb/db_extern.h>
43
44#include <dev/cons.h>
45
46#ifndef DDB_HISTORY_SIZE
47#define DDB_HISTORY_SIZE 0
48#endif /* DDB_HISTORY_SIZE */
49
50/*
51 * Character input and editing.
52 */
53
54/*
55 * We don't track output position while editing input,
56 * since input always ends with a new-line.  We just
57 * reset the line position at the end.
58 */
59char *	db_lbuf_start;	/* start of input line buffer */
60char *	db_lbuf_end;	/* end of input line buffer */
61char *	db_lc;		/* current character */
62char *	db_le;		/* one past last character */
63#if DDB_HISTORY_SIZE != 0
64char    db_history[DDB_HISTORY_SIZE];	/* start of history buffer */
65int     db_history_size = DDB_HISTORY_SIZE;/* size of history buffer */
66char *  db_history_curr = db_history;	/* start of current line */
67char *  db_history_last = db_history;	/* start of last line */
68char *  db_history_prev = (char *) 0;	/* start of previous line */
69#endif
70
71
72#define	CTRL(c)		((c) & 0x1f)
73#define	isspace(c)	((c) == ' ' || (c) == '\t')
74#define	BLANK		' '
75#define	BACKUP		'\b'
76
77static int cnmaygetc __P((void));
78
79void
80db_putstring(s, count)
81	char	*s;
82	int	count;
83{
84	while (--count >= 0)
85	    cnputc(*s++);
86}
87
88void
89db_putnchars(c, count)
90	int	c;
91	int	count;
92{
93	while (--count >= 0)
94	    cnputc(c);
95}
96
97/*
98 * Delete N characters, forward or backward
99 */
100#define	DEL_FWD		0
101#define	DEL_BWD		1
102void
103db_delete(n, bwd)
104	int	n;
105	int	bwd;
106{
107	register char *p;
108
109	if (bwd) {
110	    db_lc -= n;
111	    db_putnchars(BACKUP, n);
112	}
113	for (p = db_lc; p < db_le-n; p++) {
114	    *p = *(p+n);
115	    cnputc(*p);
116	}
117	db_putnchars(BLANK, n);
118	db_putnchars(BACKUP, db_le - db_lc);
119	db_le -= n;
120}
121
122void
123db_delete_line()
124{
125	db_delete(db_le - db_lc, DEL_FWD);
126	db_delete(db_lc - db_lbuf_start, DEL_BWD);
127	db_le = db_lc = db_lbuf_start;
128}
129
130#if DDB_HISTORY_SIZE != 0
131#define INC_DB_CURR() \
132    do { \
133	     db_history_curr++; \
134	     if (db_history_curr > \
135		 db_history + db_history_size - 1) \
136		     db_history_curr = db_history; \
137       } while (0)
138#define DEC_DB_CURR() \
139    do { \
140	     db_history_curr--; \
141	     if (db_history_curr < db_history) \
142		 db_history_curr = db_history + \
143		 db_history_size - 1; \
144       } while (0)
145#endif
146
147/* returns TRUE at end-of-line */
148int
149db_inputchar(c)
150	int	c;
151{
152	switch (c) {
153	    case CTRL('b'):
154		/* back up one character */
155		if (db_lc > db_lbuf_start) {
156		    cnputc(BACKUP);
157		    db_lc--;
158		}
159		break;
160	    case CTRL('f'):
161		/* forward one character */
162		if (db_lc < db_le) {
163		    cnputc(*db_lc);
164		    db_lc++;
165		}
166		break;
167	    case CTRL('a'):
168		/* beginning of line */
169		while (db_lc > db_lbuf_start) {
170		    cnputc(BACKUP);
171		    db_lc--;
172		}
173		break;
174	    case CTRL('e'):
175		/* end of line */
176		while (db_lc < db_le) {
177		    cnputc(*db_lc);
178		    db_lc++;
179		}
180		break;
181	    case CTRL('h'):
182	    case 0177:
183		/* erase previous character */
184		if (db_lc > db_lbuf_start)
185		    db_delete(1, DEL_BWD);
186		break;
187	    case CTRL('d'):
188		/* erase next character */
189		if (db_lc < db_le)
190		    db_delete(1, DEL_FWD);
191		break;
192	    case CTRL('k'):
193		/* delete to end of line */
194		if (db_lc < db_le)
195		    db_delete(db_le - db_lc, DEL_FWD);
196		break;
197	    case CTRL('u'):
198		/* delete line */
199	        db_delete_line();
200		break;
201	    case CTRL('t'):
202		/* twiddle last 2 characters */
203		if (db_lc >= db_lbuf_start + 2) {
204		    c = db_lc[-2];
205		    db_lc[-2] = db_lc[-1];
206		    db_lc[-1] = c;
207		    cnputc(BACKUP);
208		    cnputc(BACKUP);
209		    cnputc(db_lc[-2]);
210		    cnputc(db_lc[-1]);
211		}
212		break;
213#if DDB_HISTORY_SIZE != 0
214	    case CTRL('p'):
215	        DEC_DB_CURR();
216	        while (db_history_curr != db_history_last) {
217			DEC_DB_CURR();
218			if (*db_history_curr == '\0')
219			    break;
220		}
221		db_delete_line();
222		if (db_history_curr == db_history_last) {
223			INC_DB_CURR();
224			db_le = db_lc = db_lbuf_start;
225		} else {
226			register char *p;
227			INC_DB_CURR();
228			for (p = db_history_curr, db_le = db_lbuf_start;
229			     *p; ) {
230				*db_le++ = *p++;
231				if (p == db_history + db_history_size) {
232					p = db_history;
233				}
234			}
235			db_lc = db_le;
236		}
237		db_putstring(db_lbuf_start, db_le - db_lbuf_start);
238		break;
239	    case CTRL('n'):
240	        while (db_history_curr != db_history_last) {
241			if (*db_history_curr == '\0')
242			    break;
243			INC_DB_CURR();
244		}
245		if (db_history_curr != db_history_last) {
246			INC_DB_CURR();
247			db_delete_line();
248			if (db_history_curr != db_history_last) {
249				register char *p;
250				for (p = db_history_curr,
251				     db_le = db_lbuf_start; *p;) {
252					*db_le++ = *p++;
253					if (p == db_history +
254					    db_history_size) {
255						p = db_history;
256					}
257				}
258				db_lc = db_le;
259			}
260			db_putstring(db_lbuf_start, db_le - db_lbuf_start);
261		}
262		break;
263#endif
264	    case CTRL('r'):
265		db_putstring("^R\n", 3);
266		if (db_le > db_lbuf_start) {
267		    db_putstring(db_lbuf_start, db_le - db_lbuf_start);
268		    db_putnchars(BACKUP, db_le - db_lc);
269		}
270		break;
271	    case '\n':
272	    case '\r':
273#if DDB_HISTORY_SIZE != 0
274		/* Check if it same than previous line */
275		if (db_history_curr == db_history_prev) {
276			register char *pp, *pc;
277
278			/* Is it unmodified */
279			for (pp = db_history_prev, pc = db_lbuf_start;
280			     pc != db_le && *pp; pp++, pc++) {
281				if (*pp != *pc)
282				    break;
283				if (++pp == db_history + db_history_size) {
284					pp = db_history;
285				}
286				if (++pc == db_history + db_history_size) {
287					pc = db_history;
288				}
289			}
290			if (!*pp && pc == db_le) {
291				/* Repeted previous line, not saved */
292				db_history_curr = db_history_last;
293				*db_le++ = c;
294				return (TRUE);
295			}
296		}
297		if (db_le != db_lbuf_start) {
298			register char *p;
299			db_history_prev = db_history_last;
300			for (p = db_lbuf_start; p != db_le; p++) {
301				*db_history_last++ = *p;
302				if (db_history_last == db_history +
303				    db_history_size) {
304					db_history_last = db_history;
305				}
306			}
307			*db_history_last++ = '\0';
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		}
317		else if (c >= ' ' && c <= '~') {
318		    register char *p;
319
320		    for (p = db_le; p > db_lc; p--)
321			*p = *(p-1);
322		    *db_lc++ = c;
323		    db_le++;
324		    cnputc(c);
325		    db_putstring(db_lc, db_le - db_lc);
326		    db_putnchars(BACKUP, db_le - db_lc);
327		}
328		break;
329	}
330	return (0);
331}
332
333int
334db_readline(lstart, lsize)
335	char *	lstart;
336	int	lsize;
337{
338	db_force_whitespace();	/* synch output position */
339
340	db_lbuf_start = lstart;
341	db_lbuf_end   = lstart + lsize;
342	db_lc = lstart;
343	db_le = lstart;
344
345	while (!db_inputchar(cngetc()))
346	    continue;
347
348	db_putchar('\n');	/* synch output position */
349
350	*db_le = 0;
351	return (db_le - db_lbuf_start);
352}
353
354void
355db_check_interrupt()
356{
357	register int	c;
358
359	c = cnmaygetc();
360	switch (c) {
361	    case -1:		/* no character */
362		return;
363
364	    case CTRL('c'):
365		db_error((char *)0);
366		/*NOTREACHED*/
367
368	    case CTRL('s'):
369		do {
370		    c = cnmaygetc();
371		    if (c == CTRL('c')) {
372			db_error((char *)0);
373			/*NOTREACHED*/
374		    }
375		} while (c != CTRL('q'));
376		break;
377
378	    default:
379		/* drop on floor */
380		break;
381	}
382}
383
384static int
385cnmaygetc ()
386{
387	return (-1);
388}
389