db_input.c revision 49558 
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 1.24 1999/07/14 10:53:41 yokota 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/systm.h>
36#include <sys/cons.h>
37
38#include <ddb/ddb.h>
39#include <ddb/db_output.h>
40
41/*
42 * Character input and editing.
43 */
44
45/*
46 * We don't track output position while editing input,
47 * since input always ends with a new-line.  We just
48 * reset the line position at the end.
49 */
50static char *	db_lbuf_start;	/* start of input line buffer */
51static char *	db_lbuf_end;	/* end of input line buffer */
52static char *	db_lc;		/* current character */
53static char *	db_le;		/* one past last character */
54
55/*
56 * Simple input line history support.
57 */
58static char	db_lhistory[2048];
59static int	db_lhistlsize, db_lhistidx, db_lhistcur;
60static int	db_lhist_nlines;
61
62#define	CTRL(c)		((c) & 0x1f)
63#define	isspace(c)	((c) == ' ' || (c) == '\t')
64#define	BLANK		' '
65#define	BACKUP		'\b'
66
67static int	cnmaygetc __P((void));
68static void	db_delete __P((int n, int bwd));
69static int	db_inputchar __P((int c));
70static void	db_putnchars __P((int c, int count));
71static void	db_putstring __P((char *s, int count));
72
73void
74db_putstring(s, count)
75	char	*s;
76	int	count;
77{
78	while (--count >= 0)
79	    cnputc(*s++);
80}
81
82void
83db_putnchars(c, count)
84	int	c;
85	int	count;
86{
87	while (--count >= 0)
88	    cnputc(c);
89}
90
91/*
92 * Delete N characters, forward or backward
93 */
94#define	DEL_FWD		0
95#define	DEL_BWD		1
96void
97db_delete(n, bwd)
98	int	n;
99	int	bwd;
100{
101	register char *p;
102
103	if (bwd) {
104	    db_lc -= n;
105	    db_putnchars(BACKUP, n);
106	}
107	for (p = db_lc; p < db_le-n; p++) {
108	    *p = *(p+n);
109	    cnputc(*p);
110	}
111	db_putnchars(BLANK, n);
112	db_putnchars(BACKUP, db_le - db_lc);
113	db_le -= n;
114}
115
116/* returns TRUE at end-of-line */
117int
118db_inputchar(c)
119	int	c;
120{
121	static int escstate;
122
123	if (escstate == 1) {
124		/* ESC seen, look for [ or O */
125		if (c == '[' || c == 'O')
126			escstate++;
127		else
128			escstate = 0; /* re-init state machine */
129		return (0);
130	} else if (escstate == 2) {
131		escstate = 0;
132		/*
133		 * If a valid cursor key has been found, translate
134		 * into an emacs-style control key, and fall through.
135		 * Otherwise, drop off.
136		 */
137		switch (c) {
138		case 'A':	/* up */
139			c = CTRL('p');
140			break;
141		case 'B':	/* down */
142			c = CTRL('n');
143			break;
144		case 'C':	/* right */
145			c = CTRL('f');
146			break;
147		case 'D':	/* left */
148			c = CTRL('b');
149			break;
150		default:
151			return (0);
152		}
153	}
154
155	switch (c) {
156	    case CTRL('['):
157		escstate = 1;
158		break;
159	    case CTRL('b'):
160		/* back up one character */
161		if (db_lc > db_lbuf_start) {
162		    cnputc(BACKUP);
163		    db_lc--;
164		}
165		break;
166	    case CTRL('f'):
167		/* forward one character */
168		if (db_lc < db_le) {
169		    cnputc(*db_lc);
170		    db_lc++;
171		}
172		break;
173	    case CTRL('a'):
174		/* beginning of line */
175		while (db_lc > db_lbuf_start) {
176		    cnputc(BACKUP);
177		    db_lc--;
178		}
179		break;
180	    case CTRL('e'):
181		/* end of line */
182		while (db_lc < db_le) {
183		    cnputc(*db_lc);
184		    db_lc++;
185		}
186		break;
187	    case CTRL('h'):
188	    case 0177:
189		/* erase previous character */
190		if (db_lc > db_lbuf_start)
191		    db_delete(1, DEL_BWD);
192		break;
193	    case CTRL('d'):
194		/* erase next character */
195		if (db_lc < db_le)
196		    db_delete(1, DEL_FWD);
197		break;
198	    case CTRL('k'):
199		/* delete to end of line */
200		if (db_lc < db_le)
201		    db_delete(db_le - db_lc, DEL_FWD);
202		break;
203	    case CTRL('t'):
204		/* twiddle last 2 characters */
205		if (db_lc >= db_lbuf_start + 2) {
206		    c = db_lc[-2];
207		    db_lc[-2] = db_lc[-1];
208		    db_lc[-1] = c;
209		    cnputc(BACKUP);
210		    cnputc(BACKUP);
211		    cnputc(db_lc[-2]);
212		    cnputc(db_lc[-1]);
213		}
214		break;
215	    case CTRL('r'):
216		db_putstring("^R\n", 3);
217	    redraw:
218		if (db_le > db_lbuf_start) {
219		    db_putstring(db_lbuf_start, db_le - db_lbuf_start);
220		    db_putnchars(BACKUP, db_le - db_lc);
221		}
222		break;
223	    case CTRL('p'):
224		/* Make previous history line the active one. */
225		if (db_lhistcur >= 0) {
226		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
227			  db_lbuf_start, db_lhistlsize);
228		    db_lhistcur--;
229		    goto hist_redraw;
230		}
231		break;
232	    case CTRL('n'):
233		/* Make next history line the active one. */
234		if (db_lhistcur < db_lhistidx - 1) {
235		    db_lhistcur += 2;
236		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
237			  db_lbuf_start, db_lhistlsize);
238		} else {
239		    /*
240		     * ^N through tail of history, reset the
241		     * buffer to zero length.
242		     */
243		    *db_lbuf_start = '\0';
244		    db_lhistcur = db_lhistidx;
245		}
246
247	    hist_redraw:
248		db_putnchars(BACKUP, db_le - db_lbuf_start);
249		db_putnchars(BLANK, db_le - db_lbuf_start);
250		db_putnchars(BACKUP, db_le - db_lbuf_start);
251		db_le = index(db_lbuf_start, '\0');
252		if (db_le[-1] == '\r' || db_le[-1] == '\n')
253		    *--db_le = '\0';
254		db_lc = db_le;
255		goto redraw;
256
257	    case -1:
258		/*
259		 * eek! the console returned eof.
260		 * probably that means we HAVE no console.. we should try bail
261		 * XXX
262		 */
263		c = '\r';
264	    case '\n':
265	    case '\r':
266		*db_le++ = c;
267		return (1);
268	    default:
269		if (db_le == db_lbuf_end) {
270		    cnputc('\007');
271		}
272		else if (c >= ' ' && c <= '~') {
273		    register char *p;
274
275		    for (p = db_le; p > db_lc; p--)
276			*p = *(p-1);
277		    *db_lc++ = c;
278		    db_le++;
279		    cnputc(c);
280		    db_putstring(db_lc, db_le - db_lc);
281		    db_putnchars(BACKUP, db_le - db_lc);
282		}
283		break;
284	}
285	return (0);
286}
287
288int
289cnmaygetc()
290{
291	return (-1);
292}
293
294int
295db_readline(lstart, lsize)
296	char *	lstart;
297	int	lsize;
298{
299	if (lsize != db_lhistlsize) {
300		/*
301		 * (Re)initialize input line history.  Throw away any
302		 * existing history.
303		 */
304		db_lhist_nlines = sizeof(db_lhistory) / lsize;
305		db_lhistlsize = lsize;
306		db_lhistidx = -1;
307	}
308	db_lhistcur = db_lhistidx;
309
310	db_force_whitespace();	/* synch output position */
311
312	db_lbuf_start = lstart;
313	db_lbuf_end   = lstart + lsize;
314	db_lc = lstart;
315	db_le = lstart;
316
317	while (!db_inputchar(cngetc()))
318	    continue;
319
320	db_printf("\n");	/* synch output position */
321	*db_le = 0;
322
323	if (db_le - db_lbuf_start > 1) {
324	    /* Maintain input line history for non-empty lines. */
325	    if (++db_lhistidx == db_lhist_nlines) {
326		/* Rotate history. */
327		ovbcopy(db_lhistory + db_lhistlsize, db_lhistory,
328			db_lhistlsize * (db_lhist_nlines - 1));
329		db_lhistidx--;
330	    }
331	    bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize,
332		  db_lhistlsize);
333	}
334
335	return (db_le - db_lbuf_start);
336}
337
338void
339db_check_interrupt()
340{
341	register int	c;
342
343	c = cnmaygetc();
344	switch (c) {
345	    case -1:		/* no character */
346		return;
347
348	    case CTRL('c'):
349		db_error((char *)0);
350		/*NOTREACHED*/
351
352	    case CTRL('s'):
353		do {
354		    c = cnmaygetc();
355		    if (c == CTRL('c'))
356			db_error((char *)0);
357		} while (c != CTRL('q'));
358		break;
359
360	    default:
361		/* drop on floor */
362		break;
363	}
364}
365
366/* called from kdb_trap in db_interface.c */
367void
368cnpollc (flag)
369	int flag;
370{
371}
372