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1.1 root 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 [email protected]
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: /*
27: * HISTORY
28: * $Log: db_input.c,v $
29: * Revision 1.1 1992/03/25 21:45:10 pace
30: * Initial revision
31: *
32: * Revision 2.4 91/02/14 14:41:53 mrt
33: * Add input line editing.
34: * [90/11/11 dbg]
35: *
36: * Revision 2.3 91/02/05 17:06:32 mrt
37: * Changed to new Mach copyright
38: * [91/01/31 16:18:13 mrt]
39: *
40: * Revision 2.2 90/08/27 21:51:03 dbg
41: * Reduce lint.
42: * [90/08/07 dbg]
43: * Created.
44: * [90/07/25 dbg]
45: *
46: */
47: /*
48: * Author: David B. Golub, Carnegie Mellon University
49: * Date: 7/90
50: */
51:
52: #include "param.h"
53: #include "proc.h"
54: #include <ddb/db_output.h>
55:
56: /*
57: * Character input and editing.
58: */
59:
60: /*
61: * We don't track output position while editing input,
62: * since input always ends with a new-line. We just
63: * reset the line position at the end.
64: */
65: char * db_lbuf_start; /* start of input line buffer */
66: char * db_lbuf_end; /* end of input line buffer */
67: char * db_lc; /* current character */
68: char * db_le; /* one past last character */
69:
70: #define CTRL(c) ((c) & 0x1f)
71: #define isspace(c) ((c) == ' ' || (c) == '\t')
72: #define BLANK ' '
73: #define BACKUP '\b'
74:
75: void
76: db_putstring(s, count)
77: char *s;
78: int count;
79: {
80: while (--count >= 0)
81: cnputc(*s++);
82: }
83:
84: void
85: db_putnchars(c, count)
86: int c;
87: int count;
88: {
89: while (--count >= 0)
90: cnputc(c);
91: }
92:
93: /*
94: * Delete N characters, forward or backward
95: */
96: #define DEL_FWD 0
97: #define DEL_BWD 1
98: void
99: db_delete(n, bwd)
100: int n;
101: int bwd;
102: {
103: register char *p;
104:
105: if (bwd) {
106: db_lc -= n;
107: db_putnchars(BACKUP, n);
108: }
109: for (p = db_lc; p < db_le-n; p++) {
110: *p = *(p+n);
111: cnputc(*p);
112: }
113: db_putnchars(BLANK, n);
114: db_putnchars(BACKUP, db_le - db_lc);
115: db_le -= n;
116: }
117:
118: /* returns TRUE at end-of-line */
119: int
120: db_inputchar(c)
121: int c;
122: {
123: switch (c) {
124: case CTRL('b'):
125: /* back up one character */
126: if (db_lc > db_lbuf_start) {
127: cnputc(BACKUP);
128: db_lc--;
129: }
130: break;
131: case CTRL('f'):
132: /* forward one character */
133: if (db_lc < db_le) {
134: cnputc(*db_lc);
135: db_lc++;
136: }
137: break;
138: case CTRL('a'):
139: /* beginning of line */
140: while (db_lc > db_lbuf_start) {
141: cnputc(BACKUP);
142: db_lc--;
143: }
144: break;
145: case CTRL('e'):
146: /* end of line */
147: while (db_lc < db_le) {
148: cnputc(*db_lc);
149: db_lc++;
150: }
151: break;
152: case CTRL('h'):
153: case 0177:
154: /* erase previous character */
155: if (db_lc > db_lbuf_start)
156: db_delete(1, DEL_BWD);
157: break;
158: case CTRL('d'):
159: /* erase next character */
160: if (db_lc < db_le)
161: db_delete(1, DEL_FWD);
162: break;
163: case CTRL('k'):
164: /* delete to end of line */
165: if (db_lc < db_le)
166: db_delete(db_le - db_lc, DEL_FWD);
167: break;
168: case CTRL('t'):
169: /* twiddle last 2 characters */
170: if (db_lc >= db_lbuf_start + 2) {
171: c = db_lc[-2];
172: db_lc[-2] = db_lc[-1];
173: db_lc[-1] = c;
174: cnputc(BACKUP);
175: cnputc(BACKUP);
176: cnputc(db_lc[-2]);
177: cnputc(db_lc[-1]);
178: }
179: break;
180: case CTRL('r'):
181: db_putstring("^R\n", 3);
182: if (db_le > db_lbuf_start) {
183: db_putstring(db_lbuf_start, db_le - db_lbuf_start);
184: db_putnchars(BACKUP, db_le - db_lc);
185: }
186: break;
187: case '\n':
188: case '\r':
189: *db_le++ = c;
190: return (1);
191: default:
192: if (db_le == db_lbuf_end) {
193: cnputc('\007');
194: }
195: else if (c >= ' ' && c <= '~') {
196: register char *p;
197:
198: for (p = db_le; p > db_lc; p--)
199: *p = *(p-1);
200: *db_lc++ = c;
201: db_le++;
202: cnputc(c);
203: db_putstring(db_lc, db_le - db_lc);
204: db_putnchars(BACKUP, db_le - db_lc);
205: }
206: break;
207: }
208: return (0);
209: }
210:
211: int
212: db_readline(lstart, lsize)
213: char * lstart;
214: int lsize;
215: {
216: db_force_whitespace(); /* synch output position */
217:
218: db_lbuf_start = lstart;
219: db_lbuf_end = lstart + lsize;
220: db_lc = lstart;
221: db_le = lstart;
222:
223: while (!db_inputchar(cngetc()))
224: continue;
225:
226: db_putchar('\n'); /* synch output position */
227:
228: *db_le = 0;
229: return (db_le - db_lbuf_start);
230: }
231:
232: void
233: db_check_interrupt()
234: {
235: register int c;
236:
237: c = cnmaygetc();
238: switch (c) {
239: case -1: /* no character */
240: return;
241:
242: case CTRL('c'):
243: db_error((char *)0);
244: /*NOTREACHED*/
245:
246: case CTRL('s'):
247: do {
248: c = cnmaygetc();
249: if (c == CTRL('c'))
250: db_error((char *)0);
251: } while (c != CTRL('q'));
252: break;
253:
254: default:
255: /* drop on floor */
256: break;
257: }
258: }
259:
260: cnmaygetc ()
261: {
262: return (-1);
263: }
264:
265: /* called from kdb_trap in db_interface.c */
266: cnpollc (flag)
267: {
268: }
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