1 /* $NetBSD: db_input.c,v 1.17 2002/02/15 07:33:51 simonb Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 * 28 * Author: David B. Golub, Carnegie Mellon University 29 * Date: 7/90 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: db_input.c,v 1.17 2002/02/15 07:33:51 simonb Exp $"); 34 35 #include "opt_ddb.h" 36 37 #include <sys/param.h> 38 #include <sys/proc.h> 39 40 #include <machine/db_machdep.h> 41 42 #include <ddb/db_output.h> 43 #include <ddb/db_command.h> 44 #include <ddb/db_sym.h> 45 #include <ddb/db_extern.h> 46 47 #include <dev/cons.h> 48 49 #ifndef DDB_HISTORY_SIZE 50 #define DDB_HISTORY_SIZE 0 51 #endif /* DDB_HISTORY_SIZE */ 52 53 /* 54 * Character input and editing. 55 */ 56 57 /* 58 * We don't track output position while editing input, 59 * since input always ends with a new-line. We just 60 * reset the line position at the end. 61 */ 62 static char *db_lbuf_start; /* start of input line buffer */ 63 static char *db_lbuf_end; /* end of input line buffer */ 64 static char *db_lc; /* current character */ 65 static char *db_le; /* one past last character */ 66 #if DDB_HISTORY_SIZE != 0 67 static char db_history[DDB_HISTORY_SIZE]; /* start of history buffer */ 68 static int db_history_size = DDB_HISTORY_SIZE;/* size of history buffer */ 69 static char *db_history_curr = db_history; /* start of current line */ 70 static char *db_history_last = db_history; /* start of last line */ 71 static char *db_history_prev = (char *) 0; /* start of previous line */ 72 #endif 73 74 75 #define CTRL(c) ((c) & 0x1f) 76 #define isspace(c) ((c) == ' ' || (c) == '\t') 77 #define BLANK ' ' 78 #define BACKUP '\b' 79 80 static int cnmaygetc(void); 81 static void db_putstring(char *, int); 82 static void db_putnchars(int, int); 83 static void db_delete(int, int); 84 static void db_delete_line(void); 85 static int db_inputchar(int); 86 87 static void 88 db_putstring(char *s, int count) 89 { 90 91 while (--count >= 0) 92 cnputc(*s++); 93 } 94 95 static void 96 db_putnchars(int c, int count) 97 { 98 99 while (--count >= 0) 100 cnputc(c); 101 } 102 103 /* 104 * Delete N characters, forward or backward 105 */ 106 #define DEL_FWD 0 107 #define DEL_BWD 1 108 static void 109 db_delete(int n, int bwd) 110 { 111 char *p; 112 113 if (bwd) { 114 db_lc -= n; 115 db_putnchars(BACKUP, n); 116 } 117 for (p = db_lc; p < db_le-n; p++) { 118 *p = *(p+n); 119 cnputc(*p); 120 } 121 db_putnchars(BLANK, n); 122 db_putnchars(BACKUP, db_le - db_lc); 123 db_le -= n; 124 } 125 126 static void 127 db_delete_line(void) 128 { 129 130 db_delete(db_le - db_lc, DEL_FWD); 131 db_delete(db_lc - db_lbuf_start, DEL_BWD); 132 db_le = db_lc = db_lbuf_start; 133 } 134 135 #if DDB_HISTORY_SIZE != 0 136 #define INC_DB_CURR() \ 137 do { \ 138 db_history_curr++; \ 139 if (db_history_curr > db_history + db_history_size - 1) \ 140 db_history_curr = db_history; \ 141 } while (0) 142 #define DEC_DB_CURR() \ 143 do { \ 144 db_history_curr--; \ 145 if (db_history_curr < db_history) \ 146 db_history_curr = db_history + \ 147 db_history_size - 1; \ 148 } while (0) 149 #endif 150 151 /* returns TRUE at end-of-line */ 152 static int 153 db_inputchar(int c) 154 { 155 switch (c) { 156 case CTRL('b'): 157 /* back up one character */ 158 if (db_lc > db_lbuf_start) { 159 cnputc(BACKUP); 160 db_lc--; 161 } 162 break; 163 case CTRL('f'): 164 /* forward one character */ 165 if (db_lc < db_le) { 166 cnputc(*db_lc); 167 db_lc++; 168 } 169 break; 170 case CTRL('a'): 171 /* beginning of line */ 172 while (db_lc > db_lbuf_start) { 173 cnputc(BACKUP); 174 db_lc--; 175 } 176 break; 177 case CTRL('e'): 178 /* end of line */ 179 while (db_lc < db_le) { 180 cnputc(*db_lc); 181 db_lc++; 182 } 183 break; 184 case CTRL('h'): 185 case 0177: 186 /* erase previous character */ 187 if (db_lc > db_lbuf_start) 188 db_delete(1, DEL_BWD); 189 break; 190 case CTRL('d'): 191 /* erase next character */ 192 if (db_lc < db_le) 193 db_delete(1, DEL_FWD); 194 break; 195 case CTRL('k'): 196 /* delete to end of line */ 197 if (db_lc < db_le) 198 db_delete(db_le - db_lc, DEL_FWD); 199 break; 200 case CTRL('u'): 201 /* delete line */ 202 db_delete_line(); 203 break; 204 case CTRL('t'): 205 /* twiddle last 2 characters */ 206 if (db_lc >= db_lbuf_start + 1) { 207 if (db_lc < db_le) { 208 c = db_lc[-1]; 209 db_lc[-1] = db_lc[0]; 210 db_lc[0] = c; 211 cnputc(BACKUP); 212 cnputc(db_lc[-1]); 213 cnputc(db_lc[0]); 214 db_lc++; 215 } else if (db_lc >= db_lbuf_start + 2) { 216 c = db_lc[-2]; 217 db_lc[-2] = db_lc[-1]; 218 db_lc[-1] = c; 219 cnputc(BACKUP); 220 cnputc(BACKUP); 221 cnputc(db_lc[-2]); 222 cnputc(db_lc[-1]); 223 } 224 } 225 break; 226 #if DDB_HISTORY_SIZE != 0 227 case CTRL('p'): 228 DEC_DB_CURR(); 229 while (db_history_curr != db_history_last) { 230 DEC_DB_CURR(); 231 if (*db_history_curr == '\0') 232 break; 233 } 234 db_delete_line(); 235 if (db_history_curr == db_history_last) { 236 INC_DB_CURR(); 237 db_le = db_lc = db_lbuf_start; 238 } else { 239 char *p; 240 INC_DB_CURR(); 241 for (p = db_history_curr, db_le = db_lbuf_start; 242 *p; ) { 243 *db_le++ = *p++; 244 if (p == db_history + db_history_size) { 245 p = db_history; 246 } 247 } 248 db_lc = db_le; 249 } 250 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 251 break; 252 case CTRL('n'): 253 while (db_history_curr != db_history_last) { 254 if (*db_history_curr == '\0') 255 break; 256 INC_DB_CURR(); 257 } 258 if (db_history_curr != db_history_last) { 259 INC_DB_CURR(); 260 db_delete_line(); 261 if (db_history_curr != db_history_last) { 262 char *p; 263 for (p = db_history_curr, 264 db_le = db_lbuf_start; *p;) { 265 *db_le++ = *p++; 266 if (p == db_history + 267 db_history_size) { 268 p = db_history; 269 } 270 } 271 db_lc = db_le; 272 } 273 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 274 } 275 break; 276 #endif 277 case CTRL('r'): 278 db_putstring("^R\n", 3); 279 if (db_le > db_lbuf_start) { 280 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 281 db_putnchars(BACKUP, db_le - db_lc); 282 } 283 break; 284 case '\n': 285 case '\r': 286 #if DDB_HISTORY_SIZE != 0 287 /* Check if it same than previous line */ 288 if (db_history_curr == db_history_prev) { 289 char *pp, *pc; 290 291 /* Is it unmodified */ 292 for (pp = db_history_prev, pc = db_lbuf_start; 293 pc != db_le && *pp; pp++, pc++) { 294 if (*pp != *pc) 295 break; 296 if (++pp == db_history + db_history_size) { 297 pp = db_history; 298 } 299 if (++pc == db_history + db_history_size) { 300 pc = db_history; 301 } 302 } 303 if (!*pp && pc == db_le) { 304 /* Repeted previous line, not saved */ 305 db_history_curr = db_history_last; 306 *db_le++ = c; 307 return (TRUE); 308 } 309 } 310 if (db_le != db_lbuf_start) { 311 char *p; 312 db_history_prev = db_history_last; 313 for (p = db_lbuf_start; p != db_le; p++) { 314 *db_history_last++ = *p; 315 if (db_history_last == db_history + 316 db_history_size) { 317 db_history_last = db_history; 318 } 319 } 320 *db_history_last++ = '\0'; 321 } 322 db_history_curr = db_history_last; 323 #endif 324 *db_le++ = c; 325 return (1); 326 default: 327 if (db_le == db_lbuf_end) { 328 cnputc('\007'); 329 } 330 else if (c >= ' ' && c <= '~') { 331 char *p; 332 333 for (p = db_le; p > db_lc; p--) 334 *p = *(p-1); 335 *db_lc++ = c; 336 db_le++; 337 cnputc(c); 338 db_putstring(db_lc, db_le - db_lc); 339 db_putnchars(BACKUP, db_le - db_lc); 340 } 341 break; 342 } 343 return (0); 344 } 345 346 int 347 db_readline(char *lstart, int lsize) 348 { 349 db_force_whitespace(); /* synch output position */ 350 351 db_lbuf_start = lstart; 352 db_lbuf_end = lstart + lsize; 353 db_lc = lstart; 354 db_le = lstart; 355 356 while (!db_inputchar(cngetc())) 357 continue; 358 359 db_putchar('\n'); /* synch output position */ 360 361 *db_le = 0; 362 return (db_le - db_lbuf_start); 363 } 364 365 void 366 db_check_interrupt(void) 367 { 368 int c; 369 370 c = cnmaygetc(); 371 switch (c) { 372 case -1: /* no character */ 373 return; 374 375 case CTRL('c'): 376 db_error((char *)0); 377 /*NOTREACHED*/ 378 379 case CTRL('s'): 380 do { 381 c = cnmaygetc(); 382 if (c == CTRL('c')) { 383 db_error((char *)0); 384 /*NOTREACHED*/ 385 } 386 } while (c != CTRL('q')); 387 break; 388 389 default: 390 /* drop on floor */ 391 break; 392 } 393 } 394 395 static int 396 cnmaygetc(void) 397 { 398 399 return (-1); 400 } 401