1 /*- 2 * SPDX-License-Identifier: MIT-CMU 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 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 /* 29 * Author: David B. Golub, Carnegie Mellon University 30 * Date: 7/90 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/cons.h> 39 40 #include <ddb/ddb.h> 41 #include <ddb/db_output.h> 42 43 /* 44 * Character input and editing. 45 */ 46 47 /* 48 * We don't track output position while editing input, 49 * since input always ends with a new-line. We just 50 * reset the line position at the end. 51 */ 52 static char * db_lbuf_start; /* start of input line buffer */ 53 static char * db_lbuf_end; /* end of input line buffer */ 54 static char * db_lc; /* current character */ 55 static char * db_le; /* one past last character */ 56 57 /* 58 * Simple input line history support. 59 */ 60 static char db_lhistory[2048]; 61 static int db_lhistlsize, db_lhistidx, db_lhistcur; 62 static int db_lhist_nlines; 63 64 #define CTRL(c) ((c) & 0x1f) 65 #define BLANK ' ' 66 #define BACKUP '\b' 67 68 static int cnmaygetc(void); 69 static void db_delete(int n, int bwd); 70 static int db_inputchar(int c); 71 static void db_putnchars(int c, int count); 72 static void db_putstring(char *s, int count); 73 74 static void 75 db_putstring(s, count) 76 char *s; 77 int count; 78 { 79 while (--count >= 0) 80 cnputc(*s++); 81 } 82 83 static void 84 db_putnchars(c, count) 85 int c; 86 int count; 87 { 88 while (--count >= 0) 89 cnputc(c); 90 } 91 92 /* 93 * Delete N characters, forward or backward 94 */ 95 #define DEL_FWD 0 96 #define DEL_BWD 1 97 static void 98 db_delete(n, bwd) 99 int n; 100 int bwd; 101 { 102 char *p; 103 104 if (bwd) { 105 db_lc -= n; 106 db_putnchars(BACKUP, n); 107 } 108 for (p = db_lc; p < db_le-n; p++) { 109 *p = *(p+n); 110 cnputc(*p); 111 } 112 db_putnchars(BLANK, n); 113 db_putnchars(BACKUP, db_le - db_lc); 114 db_le -= n; 115 } 116 117 /* returns true at end-of-line */ 118 static int 119 db_inputchar(c) 120 int c; 121 { 122 static int escstate; 123 124 if (escstate == 1) { 125 /* ESC seen, look for [ or O */ 126 if (c == '[' || c == 'O') 127 escstate++; 128 else 129 escstate = 0; /* re-init state machine */ 130 return (0); 131 } else if (escstate == 2) { 132 escstate = 0; 133 /* 134 * If a valid cursor key has been found, translate 135 * into an emacs-style control key, and fall through. 136 * Otherwise, drop off. 137 */ 138 switch (c) { 139 case 'A': /* up */ 140 c = CTRL('p'); 141 break; 142 case 'B': /* down */ 143 c = CTRL('n'); 144 break; 145 case 'C': /* right */ 146 c = CTRL('f'); 147 break; 148 case 'D': /* left */ 149 c = CTRL('b'); 150 break; 151 default: 152 return (0); 153 } 154 } 155 156 switch (c) { 157 case CTRL('['): 158 escstate = 1; 159 break; 160 case CTRL('b'): 161 /* back up one character */ 162 if (db_lc > db_lbuf_start) { 163 cnputc(BACKUP); 164 db_lc--; 165 } 166 break; 167 case CTRL('f'): 168 /* forward one character */ 169 if (db_lc < db_le) { 170 cnputc(*db_lc); 171 db_lc++; 172 } 173 break; 174 case CTRL('a'): 175 /* beginning of line */ 176 while (db_lc > db_lbuf_start) { 177 cnputc(BACKUP); 178 db_lc--; 179 } 180 break; 181 case CTRL('e'): 182 /* end of line */ 183 while (db_lc < db_le) { 184 cnputc(*db_lc); 185 db_lc++; 186 } 187 break; 188 case CTRL('h'): 189 case 0177: 190 /* erase previous character */ 191 if (db_lc > db_lbuf_start) 192 db_delete(1, DEL_BWD); 193 break; 194 case CTRL('d'): 195 /* erase next character */ 196 if (db_lc < db_le) 197 db_delete(1, DEL_FWD); 198 break; 199 case CTRL('u'): 200 case CTRL('c'): 201 /* kill entire line: */ 202 /* at first, delete to beginning of line */ 203 if (db_lc > db_lbuf_start) 204 db_delete(db_lc - db_lbuf_start, DEL_BWD); 205 /* FALLTHROUGH */ 206 case CTRL('k'): 207 /* delete to end of line */ 208 if (db_lc < db_le) 209 db_delete(db_le - db_lc, DEL_FWD); 210 break; 211 case CTRL('t'): 212 /* twiddle last 2 characters */ 213 if (db_lc >= db_lbuf_start + 2) { 214 c = db_lc[-2]; 215 db_lc[-2] = db_lc[-1]; 216 db_lc[-1] = c; 217 cnputc(BACKUP); 218 cnputc(BACKUP); 219 cnputc(db_lc[-2]); 220 cnputc(db_lc[-1]); 221 } 222 break; 223 case CTRL('w'): 224 /* erase previous word */ 225 for (; db_lc > db_lbuf_start;) { 226 if (*(db_lc - 1) != ' ') 227 break; 228 db_delete(1, DEL_BWD); 229 } 230 for (; db_lc > db_lbuf_start;) { 231 if (*(db_lc - 1) == ' ') 232 break; 233 db_delete(1, DEL_BWD); 234 } 235 break; 236 case CTRL('r'): 237 db_putstring("^R\n", 3); 238 redraw: 239 if (db_le > db_lbuf_start) { 240 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 241 db_putnchars(BACKUP, db_le - db_lc); 242 } 243 break; 244 case CTRL('p'): 245 /* Make previous history line the active one. */ 246 if (db_lhistcur >= 0) { 247 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 248 db_lbuf_start, db_lhistlsize); 249 db_lhistcur--; 250 goto hist_redraw; 251 } 252 break; 253 case CTRL('n'): 254 /* Make next history line the active one. */ 255 if (db_lhistcur < db_lhistidx - 1) { 256 db_lhistcur += 2; 257 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 258 db_lbuf_start, db_lhistlsize); 259 } else { 260 /* 261 * ^N through tail of history, reset the 262 * buffer to zero length. 263 */ 264 *db_lbuf_start = '\0'; 265 db_lhistcur = db_lhistidx; 266 } 267 268 hist_redraw: 269 db_putnchars(BACKUP, db_lc - db_lbuf_start); 270 db_putnchars(BLANK, db_le - db_lbuf_start); 271 db_putnchars(BACKUP, db_le - db_lbuf_start); 272 db_le = strchr(db_lbuf_start, '\0'); 273 if (db_le[-1] == '\r' || db_le[-1] == '\n') 274 *--db_le = '\0'; 275 db_lc = db_le; 276 goto redraw; 277 278 case -1: 279 /* 280 * eek! the console returned eof. 281 * probably that means we HAVE no console.. we should try bail 282 * XXX 283 */ 284 c = '\r'; 285 case '\n': 286 /* FALLTHROUGH */ 287 case '\r': 288 *db_le++ = c; 289 return (1); 290 default: 291 if (db_le == db_lbuf_end) { 292 cnputc('\007'); 293 } 294 else if (c >= ' ' && c <= '~') { 295 char *p; 296 297 for (p = db_le; p > db_lc; p--) 298 *p = *(p-1); 299 *db_lc++ = c; 300 db_le++; 301 cnputc(c); 302 db_putstring(db_lc, db_le - db_lc); 303 db_putnchars(BACKUP, db_le - db_lc); 304 } 305 break; 306 } 307 return (0); 308 } 309 310 static int 311 cnmaygetc() 312 { 313 return (-1); 314 } 315 316 int 317 db_readline(lstart, lsize) 318 char * lstart; 319 int lsize; 320 { 321 322 if (lsize < 2) 323 return (0); 324 if (lsize != db_lhistlsize) { 325 /* 326 * (Re)initialize input line history. Throw away any 327 * existing history. 328 */ 329 db_lhist_nlines = sizeof(db_lhistory) / lsize; 330 db_lhistlsize = lsize; 331 db_lhistidx = -1; 332 } 333 db_lhistcur = db_lhistidx; 334 335 db_force_whitespace(); /* synch output position */ 336 337 db_lbuf_start = lstart; 338 db_lbuf_end = lstart + lsize - 2; /* Will append NL and NUL. */ 339 db_lc = lstart; 340 db_le = lstart; 341 342 while (!db_inputchar(cngetc())) 343 continue; 344 345 db_capture_write(lstart, db_le - db_lbuf_start); 346 db_printf("\n"); /* synch output position */ 347 *db_le = 0; 348 349 if (db_le - db_lbuf_start > 1) { 350 /* Maintain input line history for non-empty lines. */ 351 if (++db_lhistidx == db_lhist_nlines) { 352 /* Rotate history. */ 353 bcopy(db_lhistory + db_lhistlsize, db_lhistory, 354 db_lhistlsize * (db_lhist_nlines - 1)); 355 db_lhistidx--; 356 } 357 bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize, 358 db_lhistlsize); 359 } 360 361 return (db_le - db_lbuf_start); 362 } 363 364 void 365 db_check_interrupt(void) 366 { 367 int c; 368 369 c = cnmaygetc(); 370 switch (c) { 371 case -1: /* no character */ 372 return; 373 374 case CTRL('c'): 375 db_error((char *)0); 376 /*NOTREACHED*/ 377 378 case CTRL('s'): 379 do { 380 c = cnmaygetc(); 381 if (c == CTRL('c')) 382 db_error((char *)0); 383 } while (c != CTRL('q')); 384 break; 385 386 default: 387 /* drop on floor */ 388 break; 389 } 390 } 391