db_input.c revision 31005 
1/*
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19 *  School of Computer Science
20 *  Carnegie Mellon University
21 *  Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 *
26 *	$Id: db_input.c,v 1.19 1997/08/17 21:21:50 joerg Exp $
27 */
28
29/*
30 *	Author: David B. Golub, Carnegie Mellon University
31 *	Date:	7/90
32 */
33
34#include <sys/param.h>
35#include <sys/malloc.h>
36#include <sys/systm.h>
37
38#include <machine/cons.h>
39
40#include <ddb/ddb.h>
41#include <ddb/db_output.h>
42
43/*
44 * Character input and editing.
45 */
46
47/*
48 * We don't track output position while editing input,
49 * since input always ends with a new-line.  We just
50 * reset the line position at the end.
51 */
52static char *	db_lbuf_start;	/* start of input line buffer */
53static char *	db_lbuf_end;	/* end of input line buffer */
54static char *	db_lc;		/* current character */
55static char *	db_le;		/* one past last character */
56
57/*
58 * Simple input line history support.
59 */
60static char *	db_lhistory;
61static int	db_lhistlsize, db_lhistidx, db_lhistcur;
62#define DB_LHIST_NLINES 10
63
64#define	CTRL(c)		((c) & 0x1f)
65#define	isspace(c)	((c) == ' ' || (c) == '\t')
66#define	BLANK		' '
67#define	BACKUP		'\b'
68
69static int	cnmaygetc __P((void));
70static void	db_delete __P((int n, int bwd));
71static int	db_inputchar __P((int c));
72static void	db_putnchars __P((int c, int count));
73static void	db_putstring __P((char *s, int count));
74
75void
76db_putstring(s, count)
77	char	*s;
78	int	count;
79{
80	while (--count >= 0)
81	    cnputc(*s++);
82}
83
84void
85db_putnchars(c, count)
86	int	c;
87	int	count;
88{
89	while (--count >= 0)
90	    cnputc(c);
91}
92
93/*
94 * Delete N characters, forward or backward
95 */
96#define	DEL_FWD		0
97#define	DEL_BWD		1
98void
99db_delete(n, bwd)
100	int	n;
101	int	bwd;
102{
103	register char *p;
104
105	if (bwd) {
106	    db_lc -= n;
107	    db_putnchars(BACKUP, n);
108	}
109	for (p = db_lc; p < db_le-n; p++) {
110	    *p = *(p+n);
111	    cnputc(*p);
112	}
113	db_putnchars(BLANK, n);
114	db_putnchars(BACKUP, db_le - db_lc);
115	db_le -= n;
116}
117
118/* returns TRUE at end-of-line */
119int
120db_inputchar(c)
121	int	c;
122{
123	static int escstate;
124
125	if (escstate == 1) {
126		/* ESC seen, look for [ or O */
127		if (c == '[' || c == 'O')
128			escstate++;
129		else
130			escstate = 0; /* re-init state machine */
131		return (0);
132	} else if (escstate == 2) {
133		escstate = 0;
134		/*
135		 * If a valid cursor key has been found, translate
136		 * into an emacs-style control key, and fall through.
137		 * Otherwise, drop off.
138		 */
139		switch (c) {
140		case 'A':	/* up */
141			c = CTRL('p');
142			break;
143		case 'B':	/* down */
144			c = CTRL('n');
145			break;
146		case 'C':	/* right */
147			c = CTRL('f');
148			break;
149		case 'D':	/* left */
150			c = CTRL('b');
151			break;
152		default:
153			return (0);
154		}
155	}
156
157	switch (c) {
158	    case CTRL('['):
159		escstate = 1;
160		break;
161#if __i386__ && __FreeBSD__
162	    case 591:		/* syscons's idea of an arrow key... */
163#endif
164	    case CTRL('b'):
165		/* back up one character */
166		if (db_lc > db_lbuf_start) {
167		    cnputc(BACKUP);
168		    db_lc--;
169		}
170		break;
171#if __i386__ && __FreeBSD__
172	    case 593:		/* syscons's idea of an arrow key... */
173#endif
174	    case CTRL('f'):
175		/* forward one character */
176		if (db_lc < db_le) {
177		    cnputc(*db_lc);
178		    db_lc++;
179		}
180		break;
181	    case CTRL('a'):
182		/* beginning of line */
183		while (db_lc > db_lbuf_start) {
184		    cnputc(BACKUP);
185		    db_lc--;
186		}
187		break;
188	    case CTRL('e'):
189		/* end of line */
190		while (db_lc < db_le) {
191		    cnputc(*db_lc);
192		    db_lc++;
193		}
194		break;
195	    case CTRL('h'):
196	    case 0177:
197		/* erase previous character */
198		if (db_lc > db_lbuf_start)
199		    db_delete(1, DEL_BWD);
200		break;
201	    case CTRL('d'):
202		/* erase next character */
203		if (db_lc < db_le)
204		    db_delete(1, DEL_FWD);
205		break;
206	    case CTRL('k'):
207		/* delete to end of line */
208		if (db_lc < db_le)
209		    db_delete(db_le - db_lc, DEL_FWD);
210		break;
211	    case CTRL('t'):
212		/* twiddle last 2 characters */
213		if (db_lc >= db_lbuf_start + 2) {
214		    c = db_lc[-2];
215		    db_lc[-2] = db_lc[-1];
216		    db_lc[-1] = c;
217		    cnputc(BACKUP);
218		    cnputc(BACKUP);
219		    cnputc(db_lc[-2]);
220		    cnputc(db_lc[-1]);
221		}
222		break;
223	    case CTRL('r'):
224		db_putstring("^R\n", 3);
225	    redraw:
226		if (db_le > db_lbuf_start) {
227		    db_putstring(db_lbuf_start, db_le - db_lbuf_start);
228		    db_putnchars(BACKUP, db_le - db_lc);
229		}
230		break;
231#if __i386__ && __FreeBSD__
232	    case 588:		/* syscons's idea of an arrow key... */
233#endif
234	    case CTRL('p'):
235		/* Make previous history line the active one. */
236		if (db_lhistcur >= 0) {
237		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
238			  db_lbuf_start, db_lhistlsize);
239		    db_lhistcur--;
240		    goto hist_redraw;
241		}
242		break;
243#if __i386__ && __FreeBSD__
244	    case 596:		/* syscons's idea of an arrow key... */
245#endif
246	    case CTRL('n'):
247		/* Make next history line the active one. */
248		if (db_lhistcur < db_lhistidx - 1) {
249		    db_lhistcur += 2;
250		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
251			  db_lbuf_start, db_lhistlsize);
252		} else {
253		    /*
254		     * ^N through tail of history, reset the
255		     * buffer to zero length.
256		     */
257		    *db_lbuf_start = '\0';
258		    db_lhistcur = db_lhistidx;
259		}
260
261	    hist_redraw:
262		db_putnchars(BACKUP, db_le - db_lbuf_start);
263		db_putnchars(BLANK, db_le - db_lbuf_start);
264		db_putnchars(BACKUP, db_le - db_lbuf_start);
265		db_le = index(db_lbuf_start, '\0');
266		if (db_le[-1] == '\r' || db_le[-1] == '\n')
267		    *--db_le = '\0';
268		db_lc = db_le;
269		goto redraw;
270
271	    case -1:
272		/*
273		 * eek! the console returned eof.
274		 * probably that means we HAVE no console.. we should try bail
275		 * XXX
276		 */
277		c = '\r';
278	    case '\n':
279	    case '\r':
280		*db_le++ = c;
281		return (1);
282	    default:
283		if (db_le == db_lbuf_end) {
284		    cnputc('\007');
285		}
286		else if (c >= ' ' && c <= '~') {
287		    register char *p;
288
289		    for (p = db_le; p > db_lc; p--)
290			*p = *(p-1);
291		    *db_lc++ = c;
292		    db_le++;
293		    cnputc(c);
294		    db_putstring(db_lc, db_le - db_lc);
295		    db_putnchars(BACKUP, db_le - db_lc);
296		}
297		break;
298	}
299	return (0);
300}
301
302int
303cnmaygetc()
304{
305	return (-1);
306}
307
308int
309db_readline(lstart, lsize)
310	char *	lstart;
311	int	lsize;
312{
313	if (db_lhistory && lsize != db_lhistlsize) {
314		/* Should not happen, but to be sane, throw history away. */
315		FREE(db_lhistory, M_TEMP);
316		db_lhistory = 0;
317	}
318	if (db_lhistory == 0) {
319		/* Initialize input line history. */
320		db_lhistlsize = lsize;
321		db_lhistidx = -1;
322		MALLOC(db_lhistory, char *, lsize * DB_LHIST_NLINES,
323		       M_TEMP, M_NOWAIT);
324	}
325	db_lhistcur = db_lhistidx;
326
327	db_force_whitespace();	/* synch output position */
328
329	db_lbuf_start = lstart;
330	db_lbuf_end   = lstart + lsize;
331	db_lc = lstart;
332	db_le = lstart;
333
334	while (!db_inputchar(cngetc()))
335	    continue;
336
337	db_printf("\n");	/* synch output position */
338	*db_le = 0;
339
340	if (db_lhistory && (db_le - db_lbuf_start > 1)) {
341	    /* Maintain input line history for non-empty lines. */
342	    if (++db_lhistidx == DB_LHIST_NLINES) {
343		/* Rotate history. */
344		ovbcopy(db_lhistory + db_lhistlsize, db_lhistory,
345			db_lhistlsize * (DB_LHIST_NLINES - 1));
346		db_lhistidx--;
347	    }
348	    bcopy(lstart, db_lhistory + (db_lhistidx * db_lhistlsize),
349		  db_lhistlsize);
350	}
351
352	return (db_le - db_lbuf_start);
353}
354
355void
356db_check_interrupt()
357{
358	register int	c;
359
360	c = cnmaygetc();
361	switch (c) {
362	    case -1:		/* no character */
363		return;
364
365	    case CTRL('c'):
366		db_error((char *)0);
367		/*NOTREACHED*/
368
369	    case CTRL('s'):
370		do {
371		    c = cnmaygetc();
372		    if (c == CTRL('c'))
373			db_error((char *)0);
374		} while (c != CTRL('q'));
375		break;
376
377	    default:
378		/* drop on floor */
379		break;
380	}
381}
382
383/* called from kdb_trap in db_interface.c */
384void
385cnpollc (flag)
386	int flag;
387{
388}
389