db_input.c revision 31549 
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 1.22 1997/11/20 16:53:23 bde 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
37#include <machine/cons.h>
38
39#include <ddb/ddb.h>
40#include <ddb/db_output.h>
41
42/*
43 * Character input and editing.
44 */
45
46/*
47 * We don't track output position while editing input,
48 * since input always ends with a new-line.  We just
49 * reset the line position at the end.
50 */
51static char *	db_lbuf_start;	/* start of input line buffer */
52static char *	db_lbuf_end;	/* end of input line buffer */
53static char *	db_lc;		/* current character */
54static char *	db_le;		/* one past last character */
55
56/*
57 * Simple input line history support.
58 */
59static char	db_lhistory[2048];
60static int	db_lhistlsize, db_lhistidx, db_lhistcur;
61static int	db_lhist_nlines;
62
63#define	CTRL(c)		((c) & 0x1f)
64#define	isspace(c)	((c) == ' ' || (c) == '\t')
65#define	BLANK		' '
66#define	BACKUP		'\b'
67
68static int	cnmaygetc __P((void));
69static void	db_delete __P((int n, int bwd));
70static int	db_inputchar __P((int c));
71static void	db_putnchars __P((int c, int count));
72static void	db_putstring __P((char *s, int count));
73
74void
75db_putstring(s, count)
76	char	*s;
77	int	count;
78{
79	while (--count >= 0)
80	    cnputc(*s++);
81}
82
83void
84db_putnchars(c, count)
85	int	c;
86	int	count;
87{
88	while (--count >= 0)
89	    cnputc(c);
90}
91
92/*
93 * Delete N characters, forward or backward
94 */
95#define	DEL_FWD		0
96#define	DEL_BWD		1
97void
98db_delete(n, bwd)
99	int	n;
100	int	bwd;
101{
102	register char *p;
103
104	if (bwd) {
105	    db_lc -= n;
106	    db_putnchars(BACKUP, n);
107	}
108	for (p = db_lc; p < db_le-n; p++) {
109	    *p = *(p+n);
110	    cnputc(*p);
111	}
112	db_putnchars(BLANK, n);
113	db_putnchars(BACKUP, db_le - db_lc);
114	db_le -= n;
115}
116
117/* returns TRUE at end-of-line */
118int
119db_inputchar(c)
120	int	c;
121{
122	static int escstate;
123
124	if (escstate == 1) {
125		/* ESC seen, look for [ or O */
126		if (c == '[' || c == 'O')
127			escstate++;
128		else
129			escstate = 0; /* re-init state machine */
130		return (0);
131	} else if (escstate == 2) {
132		escstate = 0;
133		/*
134		 * If a valid cursor key has been found, translate
135		 * into an emacs-style control key, and fall through.
136		 * Otherwise, drop off.
137		 */
138		switch (c) {
139		case 'A':	/* up */
140			c = CTRL('p');
141			break;
142		case 'B':	/* down */
143			c = CTRL('n');
144			break;
145		case 'C':	/* right */
146			c = CTRL('f');
147			break;
148		case 'D':	/* left */
149			c = CTRL('b');
150			break;
151		default:
152			return (0);
153		}
154	}
155
156	switch (c) {
157	    case CTRL('['):
158		escstate = 1;
159		break;
160#if __i386__ && __FreeBSD__
161	    case 591:		/* syscons's idea of left arrow key */
162#endif
163	    case CTRL('b'):
164		/* back up one character */
165		if (db_lc > db_lbuf_start) {
166		    cnputc(BACKUP);
167		    db_lc--;
168		}
169		break;
170#if __i386__ && __FreeBSD__
171	    case 593:		/* syscons's idea of right arrow key */
172#endif
173	    case CTRL('f'):
174		/* forward one character */
175		if (db_lc < db_le) {
176		    cnputc(*db_lc);
177		    db_lc++;
178		}
179		break;
180	    case CTRL('a'):
181		/* beginning of line */
182		while (db_lc > db_lbuf_start) {
183		    cnputc(BACKUP);
184		    db_lc--;
185		}
186		break;
187	    case CTRL('e'):
188		/* end of line */
189		while (db_lc < db_le) {
190		    cnputc(*db_lc);
191		    db_lc++;
192		}
193		break;
194	    case CTRL('h'):
195	    case 0177:
196		/* erase previous character */
197		if (db_lc > db_lbuf_start)
198		    db_delete(1, DEL_BWD);
199		break;
200	    case CTRL('d'):
201		/* erase next character */
202		if (db_lc < db_le)
203		    db_delete(1, DEL_FWD);
204		break;
205	    case CTRL('k'):
206		/* delete to end of line */
207		if (db_lc < db_le)
208		    db_delete(db_le - db_lc, DEL_FWD);
209		break;
210	    case CTRL('t'):
211		/* twiddle last 2 characters */
212		if (db_lc >= db_lbuf_start + 2) {
213		    c = db_lc[-2];
214		    db_lc[-2] = db_lc[-1];
215		    db_lc[-1] = c;
216		    cnputc(BACKUP);
217		    cnputc(BACKUP);
218		    cnputc(db_lc[-2]);
219		    cnputc(db_lc[-1]);
220		}
221		break;
222	    case CTRL('r'):
223		db_putstring("^R\n", 3);
224	    redraw:
225		if (db_le > db_lbuf_start) {
226		    db_putstring(db_lbuf_start, db_le - db_lbuf_start);
227		    db_putnchars(BACKUP, db_le - db_lc);
228		}
229		break;
230#if __i386__ && __FreeBSD__
231	    case 588:		/* syscons's idea of up arrow key */
232#endif
233	    case CTRL('p'):
234		/* Make previous history line the active one. */
235		if (db_lhistcur >= 0) {
236		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
237			  db_lbuf_start, db_lhistlsize);
238		    db_lhistcur--;
239		    goto hist_redraw;
240		}
241		break;
242#if __i386__ && __FreeBSD__
243	    case 596:		/* syscons's idea of down arrow key */
244#endif
245	    case CTRL('n'):
246		/* Make next history line the active one. */
247		if (db_lhistcur < db_lhistidx - 1) {
248		    db_lhistcur += 2;
249		    bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
250			  db_lbuf_start, db_lhistlsize);
251		} else {
252		    /*
253		     * ^N through tail of history, reset the
254		     * buffer to zero length.
255		     */
256		    *db_lbuf_start = '\0';
257		    db_lhistcur = db_lhistidx;
258		}
259
260	    hist_redraw:
261		db_putnchars(BACKUP, db_le - db_lbuf_start);
262		db_putnchars(BLANK, db_le - db_lbuf_start);
263		db_putnchars(BACKUP, db_le - db_lbuf_start);
264		db_le = index(db_lbuf_start, '\0');
265		if (db_le[-1] == '\r' || db_le[-1] == '\n')
266		    *--db_le = '\0';
267		db_lc = db_le;
268		goto redraw;
269
270	    case -1:
271		/*
272		 * eek! the console returned eof.
273		 * probably that means we HAVE no console.. we should try bail
274		 * XXX
275		 */
276		c = '\r';
277	    case '\n':
278	    case '\r':
279		*db_le++ = c;
280		return (1);
281	    default:
282		if (db_le == db_lbuf_end) {
283		    cnputc('\007');
284		}
285		else if (c >= ' ' && c <= '~') {
286		    register char *p;
287
288		    for (p = db_le; p > db_lc; p--)
289			*p = *(p-1);
290		    *db_lc++ = c;
291		    db_le++;
292		    cnputc(c);
293		    db_putstring(db_lc, db_le - db_lc);
294		    db_putnchars(BACKUP, db_le - db_lc);
295		}
296		break;
297	}
298	return (0);
299}
300
301int
302cnmaygetc()
303{
304	return (-1);
305}
306
307int
308db_readline(lstart, lsize)
309	char *	lstart;
310	int	lsize;
311{
312	if (lsize != db_lhistlsize) {
313		/*
314		 * (Re)initialize input line history.  Throw away any
315		 * existing history.
316		 */
317		db_lhist_nlines = sizeof(db_lhistory) / lsize;
318		db_lhistlsize = lsize;
319		db_lhistidx = -1;
320	}
321	db_lhistcur = db_lhistidx;
322
323	db_force_whitespace();	/* synch output position */
324
325	db_lbuf_start = lstart;
326	db_lbuf_end   = lstart + lsize;
327	db_lc = lstart;
328	db_le = lstart;
329
330	while (!db_inputchar(cngetc()))
331	    continue;
332
333	db_printf("\n");	/* synch output position */
334	*db_le = 0;
335
336	if (db_le - db_lbuf_start > 1) {
337	    /* Maintain input line history for non-empty lines. */
338	    if (++db_lhistidx == db_lhist_nlines) {
339		/* Rotate history. */
340		ovbcopy(db_lhistory + db_lhistlsize, db_lhistory,
341			db_lhistlsize * (db_lhist_nlines - 1));
342		db_lhistidx--;
343	    }
344	    bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize,
345		  db_lhistlsize);
346	}
347
348	return (db_le - db_lbuf_start);
349}
350
351void
352db_check_interrupt()
353{
354	register int	c;
355
356	c = cnmaygetc();
357	switch (c) {
358	    case -1:		/* no character */
359		return;
360
361	    case CTRL('c'):
362		db_error((char *)0);
363		/*NOTREACHED*/
364
365	    case CTRL('s'):
366		do {
367		    c = cnmaygetc();
368		    if (c == CTRL('c'))
369			db_error((char *)0);
370		} while (c != CTRL('q'));
371		break;
372
373	    default:
374		/* drop on floor */
375		break;
376	}
377}
378
379/* called from kdb_trap in db_interface.c */
380void
381cnpollc (flag)
382	int flag;
383{
384}
385