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.
30 * Author: David B. Golub, Carnegie Mellon University
34 #include <sys/param.h>
35 #include <sys/systm.h>
39 #include <ddb/db_output.h>
42 * Character input and editing.
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.
50 static char * db_lbuf_start; /* start of input line buffer */
51 static char * db_lbuf_end; /* end of input line buffer */
52 static char * db_lc; /* current character */
53 static char * db_le; /* one past last character */
56 * Simple input line history support.
58 static char db_lhistory[2048];
59 static int db_lhistlsize, db_lhistidx, db_lhistcur;
60 static int db_lhist_nlines;
62 #define CTRL(c) ((c) & 0x1f)
66 static int cnmaygetc __P((void));
67 static void db_delete __P((int n, int bwd));
68 static int db_inputchar __P((int c));
69 static void db_putnchars __P((int c, int count));
70 static void db_putstring __P((char *s, int count));
73 db_putstring(s, count)
82 db_putnchars(c, count)
91 * Delete N characters, forward or backward
104 db_putnchars(BACKUP, n);
106 for (p = db_lc; p < db_le-n; p++) {
110 db_putnchars(BLANK, n);
111 db_putnchars(BACKUP, db_le - db_lc);
115 /* returns TRUE at end-of-line */
123 /* ESC seen, look for [ or O */
124 if (c == '[' || c == 'O')
127 escstate = 0; /* re-init state machine */
129 } else if (escstate == 2) {
132 * If a valid cursor key has been found, translate
133 * into an emacs-style control key, and fall through.
134 * Otherwise, drop off.
143 case 'C': /* right */
159 /* back up one character */
160 if (db_lc > db_lbuf_start) {
166 /* forward one character */
173 /* beginning of line */
174 while (db_lc > db_lbuf_start) {
181 while (db_lc < db_le) {
188 /* erase previous character */
189 if (db_lc > db_lbuf_start)
190 db_delete(1, DEL_BWD);
193 /* erase next character */
195 db_delete(1, DEL_FWD);
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(lstart, lsize)
298 if (lsize != db_lhistlsize) {
300 * (Re)initialize input line history. Throw away any
303 db_lhist_nlines = sizeof(db_lhistory) / lsize;
304 db_lhistlsize = lsize;
307 db_lhistcur = db_lhistidx;
309 db_force_whitespace(); /* synch output position */
311 db_lbuf_start = lstart;
312 db_lbuf_end = lstart + lsize;
316 while (!db_inputchar(cngetc()))
319 db_printf("\n"); /* synch output position */
322 if (db_le - db_lbuf_start > 1) {
323 /* Maintain input line history for non-empty lines. */
324 if (++db_lhistidx == db_lhist_nlines) {
325 /* Rotate history. */
326 ovbcopy(db_lhistory + db_lhistlsize, db_lhistory,
327 db_lhistlsize * (db_lhist_nlines - 1));
330 bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize,
334 return (db_le - db_lbuf_start);
344 case -1: /* no character */
356 } while (c != CTRL('q'));