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 /* 27 * Author: David B. Golub, Carnegie Mellon University 28 * Date: 7/90 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/cons.h> 37 38 #include <ddb/ddb.h> 39 #include <ddb/db_output.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 static char * db_lbuf_start; /* start of input line buffer */ 51 static char * db_lbuf_end; /* end of input line buffer */ 52 static char * db_lc; /* current character */ 53 static char * db_le; /* one past last character */ 54 55 /* 56 * Simple input line history support. 57 */ 58 static char db_lhistory[2048]; 59 static int db_lhistlsize, db_lhistidx, db_lhistcur; 60 static int db_lhist_nlines; 61 62 #define CTRL(c) ((c) & 0x1f) 63 #define BLANK ' ' 64 #define BACKUP '\b' 65 66 static int cnmaygetc(void); 67 static void db_delete(int n, int bwd); 68 static int db_inputchar(int c); 69 static void db_putnchars(int c, int count); 70 static void db_putstring(char *s, int count); 71 72 static void 73 db_putstring(s, count) 74 char *s; 75 int count; 76 { 77 while (--count >= 0) 78 cnputc(*s++); 79 } 80 81 static void 82 db_putnchars(c, count) 83 int c; 84 int count; 85 { 86 while (--count >= 0) 87 cnputc(c); 88 } 89 90 /* 91 * Delete N characters, forward or backward 92 */ 93 #define DEL_FWD 0 94 #define DEL_BWD 1 95 static void 96 db_delete(n, bwd) 97 int n; 98 int bwd; 99 { 100 register char *p; 101 102 if (bwd) { 103 db_lc -= n; 104 db_putnchars(BACKUP, n); 105 } 106 for (p = db_lc; p < db_le-n; p++) { 107 *p = *(p+n); 108 cnputc(*p); 109 } 110 db_putnchars(BLANK, n); 111 db_putnchars(BACKUP, db_le - db_lc); 112 db_le -= n; 113 } 114 115 /* returns TRUE at end-of-line */ 116 static int 117 db_inputchar(c) 118 int c; 119 { 120 static int escstate; 121 122 if (escstate == 1) { 123 /* ESC seen, look for [ or O */ 124 if (c == '[' || c == 'O') 125 escstate++; 126 else 127 escstate = 0; /* re-init state machine */ 128 return (0); 129 } else if (escstate == 2) { 130 escstate = 0; 131 /* 132 * If a valid cursor key has been found, translate 133 * into an emacs-style control key, and fall through. 134 * Otherwise, drop off. 135 */ 136 switch (c) { 137 case 'A': /* up */ 138 c = CTRL('p'); 139 break; 140 case 'B': /* down */ 141 c = CTRL('n'); 142 break; 143 case 'C': /* right */ 144 c = CTRL('f'); 145 break; 146 case 'D': /* left */ 147 c = CTRL('b'); 148 break; 149 default: 150 return (0); 151 } 152 } 153 154 switch (c) { 155 case CTRL('['): 156 escstate = 1; 157 break; 158 case CTRL('b'): 159 /* back up one character */ 160 if (db_lc > db_lbuf_start) { 161 cnputc(BACKUP); 162 db_lc--; 163 } 164 break; 165 case CTRL('f'): 166 /* forward one character */ 167 if (db_lc < db_le) { 168 cnputc(*db_lc); 169 db_lc++; 170 } 171 break; 172 case CTRL('a'): 173 /* beginning of line */ 174 while (db_lc > db_lbuf_start) { 175 cnputc(BACKUP); 176 db_lc--; 177 } 178 break; 179 case CTRL('e'): 180 /* end of line */ 181 while (db_lc < db_le) { 182 cnputc(*db_lc); 183 db_lc++; 184 } 185 break; 186 case CTRL('h'): 187 case 0177: 188 /* erase previous character */ 189 if (db_lc > db_lbuf_start) 190 db_delete(1, DEL_BWD); 191 break; 192 case CTRL('d'): 193 /* erase next character */ 194 if (db_lc < db_le) 195 db_delete(1, DEL_FWD); 196 break; 197 case CTRL('u'): 198 /* kill entire line: */ 199 /* at first, delete to beginning of line */ 200 if (db_lc > db_lbuf_start) 201 db_delete(db_lc - db_lbuf_start, DEL_BWD); 202 /* FALLTHROUGH */ 203 case CTRL('k'): 204 /* delete to end of line */ 205 if (db_lc < db_le) 206 db_delete(db_le - db_lc, DEL_FWD); 207 break; 208 case CTRL('t'): 209 /* twiddle last 2 characters */ 210 if (db_lc >= db_lbuf_start + 2) { 211 c = db_lc[-2]; 212 db_lc[-2] = db_lc[-1]; 213 db_lc[-1] = c; 214 cnputc(BACKUP); 215 cnputc(BACKUP); 216 cnputc(db_lc[-2]); 217 cnputc(db_lc[-1]); 218 } 219 break; 220 case CTRL('r'): 221 db_putstring("^R\n", 3); 222 redraw: 223 if (db_le > db_lbuf_start) { 224 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 225 db_putnchars(BACKUP, db_le - db_lc); 226 } 227 break; 228 case CTRL('p'): 229 /* Make previous history line the active one. */ 230 if (db_lhistcur >= 0) { 231 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 232 db_lbuf_start, db_lhistlsize); 233 db_lhistcur--; 234 goto hist_redraw; 235 } 236 break; 237 case CTRL('n'): 238 /* Make next history line the active one. */ 239 if (db_lhistcur < db_lhistidx - 1) { 240 db_lhistcur += 2; 241 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 242 db_lbuf_start, db_lhistlsize); 243 } else { 244 /* 245 * ^N through tail of history, reset the 246 * buffer to zero length. 247 */ 248 *db_lbuf_start = '\0'; 249 db_lhistcur = db_lhistidx; 250 } 251 252 hist_redraw: 253 db_putnchars(BACKUP, db_lc - db_lbuf_start); 254 db_putnchars(BLANK, db_le - db_lbuf_start); 255 db_putnchars(BACKUP, db_le - db_lbuf_start); 256 db_le = index(db_lbuf_start, '\0'); 257 if (db_le[-1] == '\r' || db_le[-1] == '\n') 258 *--db_le = '\0'; 259 db_lc = db_le; 260 goto redraw; 261 262 case -1: 263 /* 264 * eek! the console returned eof. 265 * probably that means we HAVE no console.. we should try bail 266 * XXX 267 */ 268 c = '\r'; 269 case '\n': 270 /* FALLTHROUGH */ 271 case '\r': 272 *db_le++ = c; 273 return (1); 274 default: 275 if (db_le == db_lbuf_end) { 276 cnputc('\007'); 277 } 278 else if (c >= ' ' && c <= '~') { 279 register char *p; 280 281 for (p = db_le; p > db_lc; p--) 282 *p = *(p-1); 283 *db_lc++ = c; 284 db_le++; 285 cnputc(c); 286 db_putstring(db_lc, db_le - db_lc); 287 db_putnchars(BACKUP, db_le - db_lc); 288 } 289 break; 290 } 291 return (0); 292 } 293 294 static int 295 cnmaygetc() 296 { 297 return (-1); 298 } 299 300 int 301 db_readline(lstart, lsize) 302 char * lstart; 303 int lsize; 304 { 305 306 if (lsize < 2) 307 return (0); 308 if (lsize != db_lhistlsize) { 309 /* 310 * (Re)initialize input line history. Throw away any 311 * existing history. 312 */ 313 db_lhist_nlines = sizeof(db_lhistory) / lsize; 314 db_lhistlsize = lsize; 315 db_lhistidx = -1; 316 } 317 db_lhistcur = db_lhistidx; 318 319 db_force_whitespace(); /* synch output position */ 320 321 db_lbuf_start = lstart; 322 db_lbuf_end = lstart + lsize - 2; /* Will append NL and NUL. */ 323 db_lc = lstart; 324 db_le = lstart; 325 326 while (!db_inputchar(cngetc())) 327 continue; 328 329 db_capture_write(lstart, db_le - db_lbuf_start); 330 db_printf("\n"); /* synch output position */ 331 *db_le = 0; 332 333 if (db_le - db_lbuf_start > 1) { 334 /* Maintain input line history for non-empty lines. */ 335 if (++db_lhistidx == db_lhist_nlines) { 336 /* Rotate history. */ 337 bcopy(db_lhistory + db_lhistlsize, db_lhistory, 338 db_lhistlsize * (db_lhist_nlines - 1)); 339 db_lhistidx--; 340 } 341 bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize, 342 db_lhistlsize); 343 } 344 345 return (db_le - db_lbuf_start); 346 } 347 348 void 349 db_check_interrupt() 350 { 351 register int c; 352 353 c = cnmaygetc(); 354 switch (c) { 355 case -1: /* no character */ 356 return; 357 358 case CTRL('c'): 359 db_error((char *)0); 360 /*NOTREACHED*/ 361 362 case CTRL('s'): 363 do { 364 c = cnmaygetc(); 365 if (c == CTRL('c')) 366 db_error((char *)0); 367 } while (c != CTRL('q')); 368 break; 369 370 default: 371 /* drop on floor */ 372 break; 373 } 374 } 375