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 $
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 (void);
67 static void db_delete (int n, int bwd);
68 static int db_inputchar (int c);
69 static void db_putnchars (int c, int count);
70 static void db_putstring (char *s, int count);
73 db_putstring(char *s, int count)
80 db_putnchars(int c, int count)
87 * Delete N characters, forward or backward
92 db_delete(int n, int bwd)
98 db_putnchars(BACKUP, n);
100 for (p = db_lc; p < db_le-n; p++) {
104 db_putnchars(BLANK, n);
105 db_putnchars(BACKUP, db_le - db_lc);
109 /* returns TRUE at end-of-line */
116 /* ESC seen, look for [ or O */
117 if (c == '[' || c == 'O')
120 escstate = 0; /* re-init state machine */
122 } else if (escstate == 2) {
125 * If a valid cursor key has been found, translate
126 * into an emacs-style control key, and fall through.
127 * Otherwise, drop off.
136 case 'C': /* right */
152 /* back up one character */
153 if (db_lc > db_lbuf_start) {
159 /* forward one character */
166 /* beginning of line */
167 while (db_lc > db_lbuf_start) {
174 while (db_lc < db_le) {
181 /* erase previous character */
182 if (db_lc > db_lbuf_start)
183 db_delete(1, DEL_BWD);
186 /* erase next character */
188 db_delete(1, DEL_FWD);
191 /* kill entire line: */
192 /* at first, delete to beginning of line */
193 if (db_lc > db_lbuf_start)
194 db_delete(db_lc - db_lbuf_start, DEL_BWD);
197 /* delete to end of line */
199 db_delete(db_le - db_lc, DEL_FWD);
202 /* twiddle last 2 characters */
203 if (db_lc >= db_lbuf_start + 2) {
205 db_lc[-2] = db_lc[-1];
214 db_putstring("^R\n", 3);
216 if (db_le > db_lbuf_start) {
217 db_putstring(db_lbuf_start, db_le - db_lbuf_start);
218 db_putnchars(BACKUP, db_le - db_lc);
222 /* Make previous history line the active one. */
223 if (db_lhistcur >= 0) {
224 bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
225 db_lbuf_start, db_lhistlsize);
231 /* Make next history line the active one. */
232 if (db_lhistcur < db_lhistidx - 1) {
234 bcopy(db_lhistory + db_lhistcur * db_lhistlsize,
235 db_lbuf_start, db_lhistlsize);
238 * ^N through tail of history, reset the
239 * buffer to zero length.
241 *db_lbuf_start = '\0';
242 db_lhistcur = db_lhistidx;
246 db_putnchars(BACKUP, db_le - db_lbuf_start);
247 db_putnchars(BLANK, db_le - db_lbuf_start);
248 db_putnchars(BACKUP, db_le - db_lbuf_start);
249 db_le = index(db_lbuf_start, '\0');
250 if (db_le[-1] == '\r' || db_le[-1] == '\n')
257 * eek! the console returned eof.
258 * probably that means we HAVE no console.. we should try bail
267 if (db_le == db_lbuf_end) {
270 else if (c >= ' ' && c <= '~') {
273 for (p = db_le; p > db_lc; p--)
278 db_putstring(db_lc, db_le - db_lc);
279 db_putnchars(BACKUP, db_le - db_lc);
293 db_readline(char *lstart, int lsize)
295 if (lsize != db_lhistlsize) {
297 * (Re)initialize input line history. Throw away any
300 db_lhist_nlines = sizeof(db_lhistory) / lsize;
301 db_lhistlsize = lsize;
304 db_lhistcur = db_lhistidx;
306 db_force_whitespace(); /* synch output position */
308 db_lbuf_start = lstart;
309 db_lbuf_end = lstart + lsize;
313 while (!db_inputchar(cngetc()))
316 db_printf("\n"); /* synch output position */
319 if (db_le - db_lbuf_start > 1) {
320 /* Maintain input line history for non-empty lines. */
321 if (++db_lhistidx == db_lhist_nlines) {
322 /* Rotate history. */
323 bcopy(db_lhistory + db_lhistlsize, db_lhistory,
324 db_lhistlsize * (db_lhist_nlines - 1));
327 bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize,
331 return (db_le - db_lbuf_start);
335 db_check_interrupt(void)
341 case -1: /* no character */
353 } while (c != CTRL('q'));