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 1.17 1997/02/22 09:28:23 peter Exp $ 27 */ 28 29 /* 30 * Author: David B. Golub, Carnegie Mellon University 31 * Date: 7/90 32 */ 33 34 #include <sys/param.h> 35 #include <sys/malloc.h> 36 #include <sys/systm.h> 37 38 #include <machine/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; 61 static int db_lhistlsize, db_lhistidx, db_lhistcur; 62 #define DB_LHIST_NLINES 10 63 64 #define CTRL(c) ((c) & 0x1f) 65 #define isspace(c) ((c) == ' ' || (c) == '\t') 66 #define BLANK ' ' 67 #define BACKUP '\b' 68 69 static int cnmaygetc __P((void)); 70 static void db_delete __P((int n, int bwd)); 71 static int db_inputchar __P((int c)); 72 static void db_putnchars __P((int c, int count)); 73 static void db_putstring __P((char *s, int count)); 74 75 void 76 db_putstring(s, count) 77 char *s; 78 int count; 79 { 80 while (--count >= 0) 81 cnputc(*s++); 82 } 83 84 void 85 db_putnchars(c, count) 86 int c; 87 int count; 88 { 89 while (--count >= 0) 90 cnputc(c); 91 } 92 93 /* 94 * Delete N characters, forward or backward 95 */ 96 #define DEL_FWD 0 97 #define DEL_BWD 1 98 void 99 db_delete(n, bwd) 100 int n; 101 int bwd; 102 { 103 register char *p; 104 105 if (bwd) { 106 db_lc -= n; 107 db_putnchars(BACKUP, n); 108 } 109 for (p = db_lc; p < db_le-n; p++) { 110 *p = *(p+n); 111 cnputc(*p); 112 } 113 db_putnchars(BLANK, n); 114 db_putnchars(BACKUP, db_le - db_lc); 115 db_le -= n; 116 } 117 118 /* returns TRUE at end-of-line */ 119 int 120 db_inputchar(c) 121 int c; 122 { 123 static int escstate; 124 125 if (escstate == 1) { 126 /* ESC seen, look for [ or O */ 127 if (c == '[' || c == 'O') 128 escstate++; 129 else 130 escstate = 0; /* re-init state machine */ 131 return (0); 132 } else if (escstate == 2) { 133 escstate = 0; 134 /* 135 * If a valid cursor key has been found, translate 136 * into an emacs-style control key, and fall through. 137 * Otherwise, drop off. 138 */ 139 switch (c) { 140 case 'A': /* up */ 141 c = CTRL('p'); 142 break; 143 case 'B': /* down */ 144 c = CTRL('n'); 145 break; 146 case 'C': /* right */ 147 c = CTRL('f'); 148 break; 149 case 'D': /* left */ 150 c = CTRL('b'); 151 break; 152 default: 153 return (0); 154 } 155 } 156 157 switch (c) { 158 case CTRL('['): 159 escstate = 1; 160 break; 161 case CTRL('b'): 162 /* back up one character */ 163 if (db_lc > db_lbuf_start) { 164 cnputc(BACKUP); 165 db_lc--; 166 } 167 break; 168 case CTRL('f'): 169 /* forward one character */ 170 if (db_lc < db_le) { 171 cnputc(*db_lc); 172 db_lc++; 173 } 174 break; 175 case CTRL('a'): 176 /* beginning of line */ 177 while (db_lc > db_lbuf_start) { 178 cnputc(BACKUP); 179 db_lc--; 180 } 181 break; 182 case CTRL('e'): 183 /* end of line */ 184 while (db_lc < db_le) { 185 cnputc(*db_lc); 186 db_lc++; 187 } 188 break; 189 case CTRL('h'): 190 case 0177: 191 /* erase previous character */ 192 if (db_lc > db_lbuf_start) 193 db_delete(1, DEL_BWD); 194 break; 195 case CTRL('d'): 196 /* erase next character */ 197 if (db_lc < db_le) 198 db_delete(1, DEL_FWD); 199 break; 200 case CTRL('k'): 201 /* delete to end of line */ 202 if (db_lc < db_le) 203 db_delete(db_le - db_lc, DEL_FWD); 204 break; 205 case CTRL('t'): 206 /* twiddle last 2 characters */ 207 if (db_lc >= db_lbuf_start + 2) { 208 c = db_lc[-2]; 209 db_lc[-2] = db_lc[-1]; 210 db_lc[-1] = c; 211 cnputc(BACKUP); 212 cnputc(BACKUP); 213 cnputc(db_lc[-2]); 214 cnputc(db_lc[-1]); 215 } 216 break; 217 case CTRL('r'): 218 db_putstring("^R\n", 3); 219 redraw: 220 if (db_le > db_lbuf_start) { 221 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 222 db_putnchars(BACKUP, db_le - db_lc); 223 } 224 break; 225 case CTRL('p'): 226 /* Make previous history line the active one. */ 227 if (db_lhistcur >= 0) { 228 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 229 db_lbuf_start, db_lhistlsize); 230 db_lhistcur--; 231 goto hist_redraw; 232 } 233 break; 234 case CTRL('n'): 235 /* Make next history line the active one. */ 236 if (db_lhistcur < db_lhistidx - 1) { 237 db_lhistcur += 2; 238 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 239 db_lbuf_start, db_lhistlsize); 240 } else { 241 /* 242 * ^N through tail of history, reset the 243 * buffer to zero length. 244 */ 245 *db_lbuf_start = '\0'; 246 db_lhistcur = db_lhistidx; 247 } 248 249 hist_redraw: 250 db_putnchars(BACKUP, db_le - db_lbuf_start); 251 db_putnchars(BLANK, db_le - db_lbuf_start); 252 db_putnchars(BACKUP, db_le - db_lbuf_start); 253 db_le = index(db_lbuf_start, '\0'); 254 if (db_le[-1] == '\r' || db_le[-1] == '\n') 255 *--db_le = '\0'; 256 db_lc = db_le; 257 goto redraw; 258 259 case -1: 260 /* 261 * eek! the console returned eof. 262 * probably that means we HAVE no console.. we should try bail 263 * XXX 264 */ 265 c = '\r'; 266 case '\n': 267 case '\r': 268 *db_le++ = c; 269 return (1); 270 default: 271 if (db_le == db_lbuf_end) { 272 cnputc('\007'); 273 } 274 else if (c >= ' ' && c <= '~') { 275 register char *p; 276 277 for (p = db_le; p > db_lc; p--) 278 *p = *(p-1); 279 *db_lc++ = c; 280 db_le++; 281 cnputc(c); 282 db_putstring(db_lc, db_le - db_lc); 283 db_putnchars(BACKUP, db_le - db_lc); 284 } 285 break; 286 } 287 return (0); 288 } 289 290 int 291 cnmaygetc() 292 { 293 return (-1); 294 } 295 296 int 297 db_readline(lstart, lsize) 298 char * lstart; 299 int lsize; 300 { 301 if (db_lhistory && lsize != db_lhistlsize) { 302 /* Should not happen, but to be sane, throw history away. */ 303 FREE(db_lhistory, M_TEMP); 304 db_lhistory = 0; 305 } 306 if (db_lhistory == 0) { 307 /* Initialize input line history. */ 308 db_lhistlsize = lsize; 309 db_lhistidx = -1; 310 MALLOC(db_lhistory, char *, lsize * DB_LHIST_NLINES, 311 M_TEMP, M_NOWAIT); 312 } 313 db_lhistcur = db_lhistidx; 314 315 db_force_whitespace(); /* synch output position */ 316 317 db_lbuf_start = lstart; 318 db_lbuf_end = lstart + lsize; 319 db_lc = lstart; 320 db_le = lstart; 321 322 while (!db_inputchar(cngetc())) 323 continue; 324 325 db_printf("\n"); /* synch output position */ 326 *db_le = 0; 327 328 if (db_le - db_lbuf_start > 1) { 329 /* Maintain input line history for non-empty lines. */ 330 if (++db_lhistidx == DB_LHIST_NLINES) { 331 /* Rotate history. */ 332 ovbcopy(db_lhistory + db_lhistlsize, db_lhistory, 333 db_lhistlsize * (DB_LHIST_NLINES - 1)); 334 db_lhistidx--; 335 } 336 bcopy(lstart, db_lhistory + (db_lhistidx * db_lhistlsize), 337 db_lhistlsize); 338 } 339 340 return (db_le - db_lbuf_start); 341 } 342 343 void 344 db_check_interrupt() 345 { 346 register int c; 347 348 c = cnmaygetc(); 349 switch (c) { 350 case -1: /* no character */ 351 return; 352 353 case CTRL('c'): 354 db_error((char *)0); 355 /*NOTREACHED*/ 356 357 case CTRL('s'): 358 do { 359 c = cnmaygetc(); 360 if (c == CTRL('c')) 361 db_error((char *)0); 362 } while (c != CTRL('q')); 363 break; 364 365 default: 366 /* drop on floor */ 367 break; 368 } 369 } 370 371 /* called from kdb_trap in db_interface.c */ 372 void 373 cnpollc (flag) 374 int flag; 375 { 376 } 377