2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
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.
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.
16 * Carnegie Mellon requests users of this software to return to
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
26 * $FreeBSD: src/sys/ddb/db_input.c,v 1.28.2.1 2002/03/08 16:37:10 yar Exp $
27 * $DragonFly: src/sys/ddb/db_input.c,v 1.5 2005/12/23 21:35:44 swildner Exp $
31 * Author: David B. Golub, Carnegie Mellon University
35 #include <sys/param.h>
36 #include <sys/systm.h>
40 #include <ddb/db_output.h>
43 * Character input and editing.
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.
51 static char * db_lbuf_start; /* start of input line buffer */
52 static char * db_lbuf_end; /* end of input line buffer */
53 static char * db_lc; /* current character */
54 static char * db_le; /* one past last character */
57 * Simple input line history support.
59 static char db_lhistory[2048];
60 static int db_lhistlsize, db_lhistidx, db_lhistcur;
61 static int db_lhist_nlines;
63 #define CTRL(c) ((c) & 0x1f)
67 static int cnmaygetc (void);
68 static void db_delete (int n, int bwd);
69 static int db_inputchar (int c);
70 static void db_putnchars (int c, int count);
71 static void db_putstring (char *s, int count);
74 db_putstring(char *s, int count)
81 db_putnchars(int c, int count)
88 * Delete N characters, forward or backward
93 db_delete(int n, int bwd)
99 db_putnchars(BACKUP, n);
101 for (p = db_lc; p < db_le-n; p++) {
105 db_putnchars(BLANK, n);
106 db_putnchars(BACKUP, db_le - db_lc);
110 /* returns TRUE at end-of-line */
117 /* ESC seen, look for [ or O */
118 if (c == '[' || c == 'O')
121 escstate = 0; /* re-init state machine */
123 } else if (escstate == 2) {
126 * If a valid cursor key has been found, translate
127 * into an emacs-style control key, and fall through.
128 * Otherwise, drop off.
137 case 'C': /* right */
153 /* back up one character */
154 if (db_lc > db_lbuf_start) {
160 /* forward one character */
167 /* beginning of line */
168 while (db_lc > db_lbuf_start) {
175 while (db_lc < db_le) {
182 /* erase previous character */
183 if (db_lc > db_lbuf_start)
184 db_delete(1, DEL_BWD);
187 /* erase next character */
189 db_delete(1, DEL_FWD);
192 /* kill entire line: */
193 /* at first, delete to beginning of line */
194 if (db_lc > db_lbuf_start)
195 db_delete(db_lc - db_lbuf_start, DEL_BWD);
198 /* delete to end of line */
200 db_delete(db_le - db_lc, DEL_FWD);
203 /* twiddle last 2 characters */
204 if (db_lc >= db_lbuf_start + 2) {
206 db_lc[-2] = db_lc[-1];
215 db_putstring("^R\n", 3);
217 if (db_le > db_lbuf_start) {
218 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
219 db_putnchars(BACKUP, db_le - db_lc);
223 /* Make previous history line the active one. */
224 if (db_lhistcur >= 0) {
225 bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
226 db_lbuf_start, db_lhistlsize);
232 /* Make next history line the active one. */
233 if (db_lhistcur < db_lhistidx - 1) {
235 bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
236 db_lbuf_start, db_lhistlsize);
239 * ^N through tail of history, reset the
240 * buffer to zero length.
242 *db_lbuf_start = '\0';
243 db_lhistcur = db_lhistidx;
247 db_putnchars(BACKUP, db_le - db_lbuf_start);
248 db_putnchars(BLANK, db_le - db_lbuf_start);
249 db_putnchars(BACKUP, db_le - db_lbuf_start);
250 db_le = index(db_lbuf_start, '\0');
251 if (db_le[-1] == '\r' || db_le[-1] == '\n')
258 * eek! the console returned eof.
259 * probably that means we HAVE no console.. we should try bail
268 if (db_le == db_lbuf_end) {
271 else if (c >= ' ' && c <= '~') {
274 for (p = db_le; p > db_lc; p--)
279 db_putstring(db_lc, db_le - db_lc);
280 db_putnchars(BACKUP, db_le - db_lc);
294 db_readline(char *lstart, int lsize)
296 if (lsize != db_lhistlsize) {
298 * (Re)initialize input line history. Throw away any
301 db_lhist_nlines = sizeof(db_lhistory) / lsize;
302 db_lhistlsize = lsize;
305 db_lhistcur = db_lhistidx;
307 db_force_whitespace(); /* synch output position */
309 db_lbuf_start = lstart;
310 db_lbuf_end = lstart + lsize;
314 while (!db_inputchar(cngetc()))
317 db_printf("\n"); /* synch output position */
320 if (db_le - db_lbuf_start > 1) {
321 /* Maintain input line history for non-empty lines. */
322 if (++db_lhistidx == db_lhist_nlines) {
323 /* Rotate history. */
324 ovbcopy(db_lhistory + db_lhistlsize, db_lhistory,
325 db_lhistlsize * (db_lhist_nlines - 1));
328 bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize,
332 return (db_le - db_lbuf_start);
336 db_check_interrupt(void)
342 case -1: /* no character */
354 } while (c != CTRL('q'));