db_input.c revision 31062 
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 1.20 1997/11/07 02:34:50 msmith 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 char	db_lhistory_buffer[2048];
62static int	db_lhistlsize, db_lhistidx, db_lhistcur;
63static int	db_lhist_nlines;
64
65#define	CTRL(c)		((c) & 0x1f)
66#define	isspace(c)	((c) == ' ' || (c) == '\t')
67#define	BLANK		' '
68#define	BACKUP		'\b'
69
70static int	cnmaygetc __P((void));
71static void	db_delete __P((int n, int bwd));
72static int	db_inputchar __P((int c));
73static void	db_putnchars __P((int c, int count));
74static void	db_putstring __P((char *s, int count));
75
76void
77db_putstring(s, count)
78	char	*s;
79	int	count;
80{
81	while (--count >= 0)
82	    cnputc(*s++);
83}
84
85void
86db_putnchars(c, count)
87	int	c;
88	int	count;
89{
90	while (--count >= 0)
91	    cnputc(c);
92}
93
94/*
95 * Delete N characters, forward or backward
96 */
97#define	DEL_FWD		0
98#define	DEL_BWD		1
99void
100db_delete(n, bwd)
101	int	n;
102	int	bwd;
103{
104	register char *p;
105
106	if (bwd) {
107	    db_lc -= n;
108	    db_putnchars(BACKUP, n);
109	}
110	for (p = db_lc; p < db_le-n; p++) {
111	    *p = *(p+n);
112	    cnputc(*p);
113	}
114	db_putnchars(BLANK, n);
115	db_putnchars(BACKUP, db_le - db_lc);
116	db_le -= n;
117}
118
119/* returns TRUE at end-of-line */
120int
121db_inputchar(c)
122	int	c;
123{
124	static int escstate;
125
126	if (escstate == 1) {
127		/* ESC seen, look for [ or O */
128		if (c == '[' || c == 'O')
129			escstate++;
130		else
131			escstate = 0; /* re-init state machine */
132		return (0);
133	} else if (escstate == 2) {
134		escstate = 0;
135		/*
136		 * If a valid cursor key has been found, translate
137		 * into an emacs-style control key, and fall through.
138		 * Otherwise, drop off.
139		 */
140		switch (c) {
141		case 'A':	/* up */
142			c = CTRL('p');
143			break;
144		case 'B':	/* down */
145			c = CTRL('n');
146			break;
147		case 'C':	/* right */
148			c = CTRL('f');
149			break;
150		case 'D':	/* left */
151			c = CTRL('b');
152			break;
153		default:
154			return (0);
155		}
156	}
157
158	switch (c) {
159	    case CTRL('['):
160		escstate = 1;
161		break;
162#if __i386__ && __FreeBSD__
163	    case 591:		/* syscons's idea of an arrow key... */
164#endif
165	    case CTRL('b'):
166		/* back up one character */
167		if (db_lc > db_lbuf_start) {
168		    cnputc(BACKUP);
169		    db_lc--;
170		}
171		break;
172#if __i386__ && __FreeBSD__
173	    case 593:		/* syscons's idea of an arrow key... */
174#endif
175	    case CTRL('f'):
176		/* forward one character */
177		if (db_lc < db_le) {
178		    cnputc(*db_lc);
179		    db_lc++;
180		}
181		break;
182	    case CTRL('a'):
183		/* beginning of line */
184		while (db_lc > db_lbuf_start) {
185		    cnputc(BACKUP);
186		    db_lc--;
187		}
188		break;
189	    case CTRL('e'):
190		/* end of line */
191		while (db_lc < db_le) {
192		    cnputc(*db_lc);
193		    db_lc++;
194		}
195		break;
196	    case CTRL('h'):
197	    case 0177:
198		/* erase previous character */
199		if (db_lc > db_lbuf_start)
200		    db_delete(1, DEL_BWD);
201		break;
202	    case CTRL('d'):
203		/* erase next character */
204		if (db_lc < db_le)
205		    db_delete(1, DEL_FWD);
206		break;
207	    case CTRL('k'):
208		/* delete to end of line */
209		if (db_lc < db_le)
210		    db_delete(db_le - db_lc, DEL_FWD);
211		break;
212	    case CTRL('t'):
213		/* twiddle last 2 characters */
214		if (db_lc >= db_lbuf_start + 2) {
215		    c = db_lc[-2];
216		    db_lc[-2] = db_lc[-1];
217		    db_lc[-1] = c;
218		    cnputc(BACKUP);
219		    cnputc(BACKUP);
220		    cnputc(db_lc[-2]);
221		    cnputc(db_lc[-1]);
222		}
223		break;
224	    case CTRL('r'):
225		db_putstring("^R\n", 3);
226	    redraw:
227		if (db_le > db_lbuf_start) {
228		    db_putstring(db_lbuf_start, db_le - db_lbuf_start);
229		    db_putnchars(BACKUP, db_le - db_lc);
230		}
231		break;
232#if __i386__ && __FreeBSD__
233	    case 588:		/* syscons's idea of an arrow key... */
234#endif
235	    case CTRL('p'):
236		/* Make previous history line the active one. */
237		if (db_lhistcur >= 0) {
238		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
239			  db_lbuf_start, db_lhistlsize);
240		    db_lhistcur--;
241		    goto hist_redraw;
242		}
243		break;
244#if __i386__ && __FreeBSD__
245	    case 596:		/* syscons's idea of an arrow key... */
246#endif
247	    case CTRL('n'):
248		/* Make next history line the active one. */
249		if (db_lhistcur < db_lhistidx - 1) {
250		    db_lhistcur += 2;
251		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
252			  db_lbuf_start, db_lhistlsize);
253		} else {
254		    /*
255		     * ^N through tail of history, reset the
256		     * buffer to zero length.
257		     */
258		    *db_lbuf_start = '\0';
259		    db_lhistcur = db_lhistidx;
260		}
261
262	    hist_redraw:
263		db_putnchars(BACKUP, db_le - db_lbuf_start);
264		db_putnchars(BLANK, db_le - db_lbuf_start);
265		db_putnchars(BACKUP, db_le - db_lbuf_start);
266		db_le = index(db_lbuf_start, '\0');
267		if (db_le[-1] == '\r' || db_le[-1] == '\n')
268		    *--db_le = '\0';
269		db_lc = db_le;
270		goto redraw;
271
272	    case -1:
273		/*
274		 * eek! the console returned eof.
275		 * probably that means we HAVE no console.. we should try bail
276		 * XXX
277		 */
278		c = '\r';
279	    case '\n':
280	    case '\r':
281		*db_le++ = c;
282		return (1);
283	    default:
284		if (db_le == db_lbuf_end) {
285		    cnputc('\007');
286		}
287		else if (c >= ' ' && c <= '~') {
288		    register char *p;
289
290		    for (p = db_le; p > db_lc; p--)
291			*p = *(p-1);
292		    *db_lc++ = c;
293		    db_le++;
294		    cnputc(c);
295		    db_putstring(db_lc, db_le - db_lc);
296		    db_putnchars(BACKUP, db_le - db_lc);
297		}
298		break;
299	}
300	return (0);
301}
302
303int
304cnmaygetc()
305{
306	return (-1);
307}
308
309int
310db_readline(lstart, lsize)
311	char *	lstart;
312	int	lsize;
313{
314	if (db_lhistory && lsize != db_lhistlsize) {
315		/* Should not happen, but to be sane, throw history away. */
316		db_lhistory = NULL;
317	}
318	if (db_lhistory == NULL) {
319		/* Initialize input line history. */
320		db_lhistory = db_lhistory_buffer;
321		db_lhist_nlines = (sizeof db_lhistory_buffer) / lsize;
322		db_lhistlsize = lsize;
323		db_lhistidx = -1;
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