| 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 Software.Distribution@CS.CMU.EDU |
| 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 | * $Id: db_input.c,v 1.3 1993/11/25 01:30:06 wollman Exp $ |
| 27 | */ |
| 28 | |
| 29 | /* |
| 30 | * Author: David B. Golub, Carnegie Mellon University |
| 31 | * Date: 7/90 |
| 32 | */ |
| 33 | |
| 34 | #include "param.h" |
| 35 | #include "systm.h" |
| 36 | #include "proc.h" |
| 37 | #include "ddb/ddb.h" |
| 38 | #include "ddb/db_output.h" |
| 39 | #include "machine/cons.h" |
| 40 | |
| 41 | /* |
| 42 | * Character input and editing. |
| 43 | */ |
| 44 | |
| 45 | /* |
| 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. |
| 49 | */ |
| 50 | char * db_lbuf_start; /* start of input line buffer */ |
| 51 | char * db_lbuf_end; /* end of input line buffer */ |
| 52 | char * db_lc; /* current character */ |
| 53 | char * db_le; /* one past last character */ |
| 54 | |
| 55 | #define CTRL(c) ((c) & 0x1f) |
| 56 | #define isspace(c) ((c) == ' ' || (c) == '\t') |
| 57 | #define BLANK ' ' |
| 58 | #define BACKUP '\b' |
| 59 | |
| 60 | void |
| 61 | db_putstring(s, count) |
| 62 | char *s; |
| 63 | int count; |
| 64 | { |
| 65 | while (--count >= 0) |
| 66 | cnputc(*s++); |
| 67 | } |
| 68 | |
| 69 | void |
| 70 | db_putnchars(c, count) |
| 71 | int c; |
| 72 | int count; |
| 73 | { |
| 74 | while (--count >= 0) |
| 75 | cnputc(c); |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * Delete N characters, forward or backward |
| 80 | */ |
| 81 | #define DEL_FWD 0 |
| 82 | #define DEL_BWD 1 |
| 83 | void |
| 84 | db_delete(n, bwd) |
| 85 | int n; |
| 86 | int bwd; |
| 87 | { |
| 88 | register char *p; |
| 89 | |
| 90 | if (bwd) { |
| 91 | db_lc -= n; |
| 92 | db_putnchars(BACKUP, n); |
| 93 | } |
| 94 | for (p = db_lc; p < db_le-n; p++) { |
| 95 | *p = *(p+n); |
| 96 | cnputc(*p); |
| 97 | } |
| 98 | db_putnchars(BLANK, n); |
| 99 | db_putnchars(BACKUP, db_le - db_lc); |
| 100 | db_le -= n; |
| 101 | } |
| 102 | |
| 103 | /* returns TRUE at end-of-line */ |
| 104 | int |
| 105 | db_inputchar(c) |
| 106 | int c; |
| 107 | { |
| 108 | switch (c) { |
| 109 | case CTRL('b'): |
| 110 | /* back up one character */ |
| 111 | if (db_lc > db_lbuf_start) { |
| 112 | cnputc(BACKUP); |
| 113 | db_lc--; |
| 114 | } |
| 115 | break; |
| 116 | case CTRL('f'): |
| 117 | /* forward one character */ |
| 118 | if (db_lc < db_le) { |
| 119 | cnputc(*db_lc); |
| 120 | db_lc++; |
| 121 | } |
| 122 | break; |
| 123 | case CTRL('a'): |
| 124 | /* beginning of line */ |
| 125 | while (db_lc > db_lbuf_start) { |
| 126 | cnputc(BACKUP); |
| 127 | db_lc--; |
| 128 | } |
| 129 | break; |
| 130 | case CTRL('e'): |
| 131 | /* end of line */ |
| 132 | while (db_lc < db_le) { |
| 133 | cnputc(*db_lc); |
| 134 | db_lc++; |
| 135 | } |
| 136 | break; |
| 137 | case CTRL('h'): |
| 138 | case 0177: |
| 139 | /* erase previous character */ |
| 140 | if (db_lc > db_lbuf_start) |
| 141 | db_delete(1, DEL_BWD); |
| 142 | break; |
| 143 | case CTRL('d'): |
| 144 | /* erase next character */ |
| 145 | if (db_lc < db_le) |
| 146 | db_delete(1, DEL_FWD); |
| 147 | break; |
| 148 | case CTRL('k'): |
| 149 | /* delete to end of line */ |
| 150 | if (db_lc < db_le) |
| 151 | db_delete(db_le - db_lc, DEL_FWD); |
| 152 | break; |
| 153 | case CTRL('t'): |
| 154 | /* twiddle last 2 characters */ |
| 155 | if (db_lc >= db_lbuf_start + 2) { |
| 156 | c = db_lc[-2]; |
| 157 | db_lc[-2] = db_lc[-1]; |
| 158 | db_lc[-1] = c; |
| 159 | cnputc(BACKUP); |
| 160 | cnputc(BACKUP); |
| 161 | cnputc(db_lc[-2]); |
| 162 | cnputc(db_lc[-1]); |
| 163 | } |
| 164 | break; |
| 165 | case CTRL('r'): |
| 166 | db_putstring("^R\n", 3); |
| 167 | if (db_le > db_lbuf_start) { |
| 168 | db_putstring(db_lbuf_start, db_le - db_lbuf_start); |
| 169 | db_putnchars(BACKUP, db_le - db_lc); |
| 170 | } |
| 171 | break; |
| 172 | case '\n': |
| 173 | case '\r': |
| 174 | *db_le++ = c; |
| 175 | return (1); |
| 176 | default: |
| 177 | if (db_le == db_lbuf_end) { |
| 178 | cnputc('\007'); |
| 179 | } |
| 180 | else if (c >= ' ' && c <= '~') { |
| 181 | register char *p; |
| 182 | |
| 183 | for (p = db_le; p > db_lc; p--) |
| 184 | *p = *(p-1); |
| 185 | *db_lc++ = c; |
| 186 | db_le++; |
| 187 | cnputc(c); |
| 188 | db_putstring(db_lc, db_le - db_lc); |
| 189 | db_putnchars(BACKUP, db_le - db_lc); |
| 190 | } |
| 191 | break; |
| 192 | } |
| 193 | return (0); |
| 194 | } |
| 195 | |
| 196 | int |
| 197 | db_readline(lstart, lsize) |
| 198 | char * lstart; |
| 199 | int lsize; |
| 200 | { |
| 201 | db_force_whitespace(); /* synch output position */ |
| 202 | |
| 203 | db_lbuf_start = lstart; |
| 204 | db_lbuf_end = lstart + lsize; |
| 205 | db_lc = lstart; |
| 206 | db_le = lstart; |
| 207 | |
| 208 | while (!db_inputchar(cngetc())) |
| 209 | continue; |
| 210 | |
| 211 | db_putchar('\n'); /* synch output position */ |
| 212 | |
| 213 | *db_le = 0; |
| 214 | return (db_le - db_lbuf_start); |
| 215 | } |
| 216 | |
| 217 | void |
| 218 | db_check_interrupt() |
| 219 | { |
| 220 | register int c; |
| 221 | |
| 222 | c = cnmaygetc(); |
| 223 | switch (c) { |
| 224 | case -1: /* no character */ |
| 225 | return; |
| 226 | |
| 227 | case CTRL('c'): |
| 228 | db_error((char *)0); |
| 229 | /*NOTREACHED*/ |
| 230 | |
| 231 | case CTRL('s'): |
| 232 | do { |
| 233 | c = cnmaygetc(); |
| 234 | if (c == CTRL('c')) |
| 235 | db_error((char *)0); |
| 236 | } while (c != CTRL('q')); |
| 237 | break; |
| 238 | |
| 239 | default: |
| 240 | /* drop on floor */ |
| 241 | break; |
| 242 | } |
| 243 | } |
| 244 | |
| 245 | int |
| 246 | cnmaygetc (void) |
| 247 | { |
| 248 | return (-1); |
| 249 | } |
| 250 | |
| 251 | /* called from kdb_trap in db_interface.c */ |
| 252 | void |
| 253 | cnpollc (flag) |
| 254 | int flag; |
| 255 | { |
| 256 | } |