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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 $
1.1.1.2 ! root 29: * Revision 1.1.1.1 1993/03/21 09:46:26 cgd
! 30: * initial import of 386bsd-0.1 sources
! 31: *
1.1 root 32: * Revision 1.1 1992/03/25 21:45:10 pace
33: * Initial revision
34: *
35: * Revision 2.4 91/02/14 14:41:53 mrt
36: * Add input line editing.
37: * [90/11/11 dbg]
38: *
39: * Revision 2.3 91/02/05 17:06:32 mrt
40: * Changed to new Mach copyright
41: * [91/01/31 16:18:13 mrt]
42: *
43: * Revision 2.2 90/08/27 21:51:03 dbg
44: * Reduce lint.
45: * [90/08/07 dbg]
46: * Created.
47: * [90/07/25 dbg]
48: *
49: */
50: /*
51: * Author: David B. Golub, Carnegie Mellon University
52: * Date: 7/90
53: */
54:
55: #include "param.h"
56: #include "proc.h"
57: #include <ddb/db_output.h>
58:
59: /*
60: * Character input and editing.
61: */
62:
63: /*
64: * We don't track output position while editing input,
65: * since input always ends with a new-line. We just
66: * reset the line position at the end.
67: */
68: char * db_lbuf_start; /* start of input line buffer */
69: char * db_lbuf_end; /* end of input line buffer */
70: char * db_lc; /* current character */
71: char * db_le; /* one past last character */
72:
73: #define CTRL(c) ((c) & 0x1f)
74: #define isspace(c) ((c) == ' ' || (c) == '\t')
75: #define BLANK ' '
76: #define BACKUP '\b'
77:
78: void
79: db_putstring(s, count)
80: char *s;
81: int count;
82: {
83: while (--count >= 0)
84: cnputc(*s++);
85: }
86:
87: void
88: db_putnchars(c, count)
89: int c;
90: int count;
91: {
92: while (--count >= 0)
93: cnputc(c);
94: }
95:
96: /*
97: * Delete N characters, forward or backward
98: */
99: #define DEL_FWD 0
100: #define DEL_BWD 1
101: void
102: db_delete(n, bwd)
103: int n;
104: int bwd;
105: {
106: register char *p;
107:
108: if (bwd) {
109: db_lc -= n;
110: db_putnchars(BACKUP, n);
111: }
112: for (p = db_lc; p < db_le-n; p++) {
113: *p = *(p+n);
114: cnputc(*p);
115: }
116: db_putnchars(BLANK, n);
117: db_putnchars(BACKUP, db_le - db_lc);
118: db_le -= n;
119: }
120:
121: /* returns TRUE at end-of-line */
122: int
123: db_inputchar(c)
124: int c;
125: {
126: switch (c) {
127: case CTRL('b'):
128: /* back up one character */
129: if (db_lc > db_lbuf_start) {
130: cnputc(BACKUP);
131: db_lc--;
132: }
133: break;
134: case CTRL('f'):
135: /* forward one character */
136: if (db_lc < db_le) {
137: cnputc(*db_lc);
138: db_lc++;
139: }
140: break;
141: case CTRL('a'):
142: /* beginning of line */
143: while (db_lc > db_lbuf_start) {
144: cnputc(BACKUP);
145: db_lc--;
146: }
147: break;
148: case CTRL('e'):
149: /* end of line */
150: while (db_lc < db_le) {
151: cnputc(*db_lc);
152: db_lc++;
153: }
154: break;
155: case CTRL('h'):
156: case 0177:
157: /* erase previous character */
158: if (db_lc > db_lbuf_start)
159: db_delete(1, DEL_BWD);
160: break;
161: case CTRL('d'):
162: /* erase next character */
163: if (db_lc < db_le)
164: db_delete(1, DEL_FWD);
165: break;
166: case CTRL('k'):
167: /* delete to end of line */
168: if (db_lc < db_le)
169: db_delete(db_le - db_lc, DEL_FWD);
170: break;
171: case CTRL('t'):
172: /* twiddle last 2 characters */
173: if (db_lc >= db_lbuf_start + 2) {
174: c = db_lc[-2];
175: db_lc[-2] = db_lc[-1];
176: db_lc[-1] = c;
177: cnputc(BACKUP);
178: cnputc(BACKUP);
179: cnputc(db_lc[-2]);
180: cnputc(db_lc[-1]);
181: }
182: break;
183: case CTRL('r'):
184: db_putstring("^R\n", 3);
185: if (db_le > db_lbuf_start) {
186: db_putstring(db_lbuf_start, db_le - db_lbuf_start);
187: db_putnchars(BACKUP, db_le - db_lc);
188: }
189: break;
190: case '\n':
191: case '\r':
192: *db_le++ = c;
193: return (1);
194: default:
195: if (db_le == db_lbuf_end) {
196: cnputc('\007');
197: }
198: else if (c >= ' ' && c <= '~') {
199: register char *p;
200:
201: for (p = db_le; p > db_lc; p--)
202: *p = *(p-1);
203: *db_lc++ = c;
204: db_le++;
205: cnputc(c);
206: db_putstring(db_lc, db_le - db_lc);
207: db_putnchars(BACKUP, db_le - db_lc);
208: }
209: break;
210: }
211: return (0);
212: }
213:
214: int
215: db_readline(lstart, lsize)
216: char * lstart;
217: int lsize;
218: {
219: db_force_whitespace(); /* synch output position */
220:
221: db_lbuf_start = lstart;
222: db_lbuf_end = lstart + lsize;
223: db_lc = lstart;
224: db_le = lstart;
225:
226: while (!db_inputchar(cngetc()))
227: continue;
228:
229: db_putchar('\n'); /* synch output position */
230:
231: *db_le = 0;
232: return (db_le - db_lbuf_start);
233: }
234:
235: void
236: db_check_interrupt()
237: {
238: register int c;
239:
240: c = cnmaygetc();
241: switch (c) {
242: case -1: /* no character */
243: return;
244:
245: case CTRL('c'):
246: db_error((char *)0);
247: /*NOTREACHED*/
248:
249: case CTRL('s'):
250: do {
251: c = cnmaygetc();
252: if (c == CTRL('c'))
253: db_error((char *)0);
254: } while (c != CTRL('q'));
255: break;
256:
257: default:
258: /* drop on floor */
259: break;
260: }
261: }
262:
263: cnmaygetc ()
264: {
265: return (-1);
266: }
267:
268: /* called from kdb_trap in db_interface.c */
269: cnpollc (flag)
270: {
271: }
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