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