1 /* $NetBSD: db_input.c,v 1.28 2020/10/30 06:57:08 skrll 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 (at) 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 1.28 2020/10/30 06:57:08 skrll Exp $"); 34 35 #ifdef _KERNEL_OPT 36 #include "opt_ddbparam.h" 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/proc.h> 41 42 #include <ddb/ddb.h> 43 44 #include <dev/cons.h> 45 46 #ifndef DDB_HISTORY_SIZE 47 #define DDB_HISTORY_SIZE 0 48 #endif /* DDB_HISTORY_SIZE */ 49 50 /* 51 * Character input and editing. 52 */ 53 54 /* 55 * We don't track output position while editing input, 56 * since input always ends with a new-line. We just 57 * reset the line position at the end. 58 */ 59 static char *db_lbuf_start; /* start of input line buffer */ 60 static char *db_lbuf_end; /* end of input line buffer */ 61 static char *db_lc; /* current character */ 62 static char *db_le; /* one past last character */ 63 #if DDB_HISTORY_SIZE != 0 64 static char db_history[DDB_HISTORY_SIZE]; /* start of history buffer */ 65 static char *db_history_curr = db_history; /* start of current line */ 66 static char *db_history_last = db_history; /* start of last line */ 67 static char *db_history_prev = (char *) 0; /* start of previous line */ 68 #endif 69 70 71 #define CTRL(c) ((c) & 0x1f) 72 #define isspace(c) ((c) == ' ' || (c) == '\t') 73 #define BLANK ' ' 74 #define BACKUP '\b' 75 76 static int cnmaygetc(void); 77 static void db_putstring(const char *, int); 78 static void db_putnchars(int, int); 79 static void db_delete(int, int); 80 static void db_delete_line(void); 81 static int db_inputchar(int); 82 83 static void 84 db_putstring(const char *s, int count) 85 { 86 87 while (--count >= 0) 88 cnputc(*s++); 89 } 90 91 static void 92 db_putnchars(int c, int count) 93 { 94 95 while (--count >= 0) 96 cnputc(c); 97 } 98 99 /* 100 * Delete N characters, forward or backward 101 */ 102 #define DEL_FWD 0 103 #define DEL_BWD 1 104 static void 105 db_delete(int n, int bwd) 106 { 107 char *p; 108 109 if (bwd) { 110 db_lc -= n; 111 db_putnchars(BACKUP, n); 112 } 113 for (p = db_lc; p < db_le-n; p++) { 114 *p = *(p+n); 115 cnputc(*p); 116 } 117 db_putnchars(BLANK, n); 118 db_putnchars(BACKUP, db_le - db_lc); 119 db_le -= n; 120 } 121 122 static void 123 db_delete_line(void) 124 { 125 126 db_delete(db_le - db_lc, DEL_FWD); 127 db_delete(db_lc - db_lbuf_start, DEL_BWD); 128 db_le = db_lc = db_lbuf_start; 129 } 130 131 #if DDB_HISTORY_SIZE != 0 132 133 #define INC_DB_CURR() do { \ 134 ++db_history_curr; \ 135 if (db_history_curr > db_history + DDB_HISTORY_SIZE - 1) \ 136 db_history_curr = db_history; \ 137 } while (0) 138 #define DEC_DB_CURR() do { \ 139 --db_history_curr; \ 140 if (db_history_curr < db_history) \ 141 db_history_curr = db_history + DDB_HISTORY_SIZE - 1; \ 142 } while (0) 143 144 static inline void 145 db_hist_put(int c) 146 { 147 KASSERT(&db_history[0] <= db_history_last); 148 KASSERT(db_history_last <= &db_history[DDB_HISTORY_SIZE-1]); 149 150 *db_history_last++ = c; 151 152 if (db_history_last > &db_history[DDB_HISTORY_SIZE-1]) 153 db_history_last = db_history; 154 } 155 #endif 156 157 158 /* returns true at end-of-line */ 159 static int 160 db_inputchar(int c) 161 { 162 switch (c) { 163 case CTRL('b'): 164 /* back up one character */ 165 if (db_lc > db_lbuf_start) { 166 cnputc(BACKUP); 167 db_lc--; 168 } 169 break; 170 case CTRL('f'): 171 /* forward one character */ 172 if (db_lc < db_le) { 173 cnputc(*db_lc); 174 db_lc++; 175 } 176 break; 177 case CTRL('a'): 178 /* beginning of line */ 179 while (db_lc > db_lbuf_start) { 180 cnputc(BACKUP); 181 db_lc--; 182 } 183 break; 184 case CTRL('e'): 185 /* end of line */ 186 while (db_lc < db_le) { 187 cnputc(*db_lc); 188 db_lc++; 189 } 190 break; 191 case CTRL('h'): 192 case 0177: 193 /* erase previous character */ 194 if (db_lc > db_lbuf_start) 195 db_delete(1, DEL_BWD); 196 break; 197 case CTRL('d'): 198 /* erase next character */ 199 if (db_lc < db_le) 200 db_delete(1, DEL_FWD); 201 break; 202 case CTRL('k'): 203 /* delete to end of line */ 204 if (db_lc < db_le) 205 db_delete(db_le - db_lc, DEL_FWD); 206 break; 207 case CTRL('u'): 208 /* delete line */ 209 db_delete_line(); 210 break; 211 case CTRL('t'): 212 /* twiddle last 2 characters */ 213 if (db_lc >= db_lbuf_start + 1) { 214 if (db_lc < db_le) { 215 c = db_lc[-1]; 216 db_lc[-1] = db_lc[0]; 217 db_lc[0] = c; 218 cnputc(BACKUP); 219 cnputc(db_lc[-1]); 220 cnputc(db_lc[0]); 221 db_lc++; 222 } else if (db_lc >= db_lbuf_start + 2) { 223 c = db_lc[-2]; 224 db_lc[-2] = db_lc[-1]; 225 db_lc[-1] = c; 226 cnputc(BACKUP); 227 cnputc(BACKUP); 228 cnputc(db_lc[-2]); 229 cnputc(db_lc[-1]); 230 } 231 } 232 break; 233 #if DDB_HISTORY_SIZE != 0 234 case CTRL('p'): 235 DEC_DB_CURR(); 236 while (db_history_curr != db_history_last) { 237 DEC_DB_CURR(); 238 if (*db_history_curr == '\0') 239 break; 240 } 241 db_delete_line(); 242 if (db_history_curr == db_history_last) { 243 INC_DB_CURR(); 244 db_le = db_lc = db_lbuf_start; 245 } else { 246 char *p; 247 INC_DB_CURR(); 248 for (p = db_history_curr, db_le = db_lbuf_start; 249 *p; ) { 250 *db_le++ = *p++; 251 if (p >= db_history + DDB_HISTORY_SIZE) { 252 p = db_history; 253 } 254 } 255 db_lc = db_le; 256 } 257 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 258 break; 259 case CTRL('n'): 260 while (db_history_curr != db_history_last) { 261 if (*db_history_curr == '\0') 262 break; 263 INC_DB_CURR(); 264 } 265 if (db_history_curr != db_history_last) { 266 INC_DB_CURR(); 267 db_delete_line(); 268 if (db_history_curr != db_history_last) { 269 char *p; 270 for (p = db_history_curr, 271 db_le = db_lbuf_start; *p;) { 272 *db_le++ = *p++; 273 if (p >= db_history + DDB_HISTORY_SIZE) { 274 p = db_history; 275 } 276 } 277 db_lc = db_le; 278 } 279 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 280 } 281 break; 282 #endif 283 case CTRL('r'): 284 db_putstring("^R\n", 3); 285 if (db_le > db_lbuf_start) { 286 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 287 db_putnchars(BACKUP, db_le - db_lc); 288 } 289 break; 290 case '\n': 291 case '\r': 292 #if DDB_HISTORY_SIZE != 0 293 /* Check if it same than previous line */ 294 if (db_history_curr == db_history_prev) { 295 char *pp, *pc; 296 297 /* Is it unmodified */ 298 for (pp = db_history_prev, pc = db_lbuf_start; 299 pc != db_le && *pp; pp++, pc++) { 300 if (*pp != *pc) 301 break; 302 if (++pp >= db_history + DDB_HISTORY_SIZE) { 303 pp = db_history; 304 } 305 if (++pc >= db_history + DDB_HISTORY_SIZE) { 306 pc = db_history; 307 } 308 } 309 if (!*pp && pc == db_le) { 310 /* Repeted previous line, not saved */ 311 db_history_curr = db_history_last; 312 *db_le++ = c; 313 return (true); 314 } 315 } 316 if (db_le != db_lbuf_start) { 317 char *p; 318 319 db_history_prev = db_history_last; 320 321 for (p = db_lbuf_start; p != db_le; ) { 322 db_hist_put(*p++); 323 } 324 db_hist_put(0); 325 } 326 db_history_curr = db_history_last; 327 #endif 328 *db_le++ = c; 329 return (1); 330 default: 331 if (db_le == db_lbuf_end) { 332 cnputc('\007'); 333 } 334 else if (c >= ' ' && c <= '~') { 335 char *p; 336 337 for (p = db_le; p > db_lc; p--) 338 *p = *(p-1); 339 *db_lc++ = c; 340 db_le++; 341 cnputc(c); 342 db_putstring(db_lc, db_le - db_lc); 343 db_putnchars(BACKUP, db_le - db_lc); 344 } 345 break; 346 } 347 return (0); 348 } 349 350 int 351 db_readline(char *lstart, int lsize) 352 { 353 354 db_force_whitespace(); /* synch output position */ 355 356 db_lbuf_start = lstart; 357 db_lbuf_end = lstart + lsize; 358 db_lc = lstart; 359 db_le = lstart; 360 361 while (!db_inputchar(cngetc())) 362 continue; 363 364 db_putchar('\n'); /* synch output position */ 365 366 *db_le = 0; 367 return (db_le - db_lbuf_start); 368 } 369 370 void 371 db_check_interrupt(void) 372 { 373 int c; 374 375 c = cnmaygetc(); 376 switch (c) { 377 case -1: /* no character */ 378 return; 379 380 case CTRL('c'): 381 db_error((char *)0); 382 /*NOTREACHED*/ 383 384 case CTRL('s'): 385 do { 386 c = cnmaygetc(); 387 if (c == CTRL('c')) { 388 db_error((char *)0); 389 /*NOTREACHED*/ 390 } 391 } while (c != CTRL('q')); 392 break; 393 394 default: 395 /* drop on floor */ 396 break; 397 } 398 } 399 400 static int 401 cnmaygetc(void) 402 { 403 404 return (-1); 405 } 406
Indexes created Sun Sep 21 20:09:37 GMT 2025