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 * $FreeBSD: src/sys/ddb/db_input.c,v 1.28.2.1 2002/03/08 16:37:10 yar Exp $ 27 * $DragonFly: src/sys/ddb/db_input.c,v 1.5 2005/12/23 21:35:44 swildner Exp $ 28 */ 29 30 /* 31 * Author: David B. Golub, Carnegie Mellon University 32 * Date: 7/90 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/cons.h> 38 39 #include <ddb/ddb.h> 40 #include <ddb/db_output.h> 41 42 /* 43 * Character input and editing. 44 */ 45 46 /* 47 * We don't track output position while editing input, 48 * since input always ends with a new-line. We just 49 * reset the line position at the end. 50 */ 51 static char * db_lbuf_start; /* start of input line buffer */ 52 static char * db_lbuf_end; /* end of input line buffer */ 53 static char * db_lc; /* current character */ 54 static char * db_le; /* one past last character */ 55 56 /* 57 * Simple input line history support. 58 */ 59 static char db_lhistory[2048]; 60 static int db_lhistlsize, db_lhistidx, db_lhistcur; 61 static int db_lhist_nlines; 62 63 #define CTRL(c) ((c) & 0x1f) 64 #define BLANK ' ' 65 #define BACKUP '\b' 66 67 static int cnmaygetc (void); 68 static void db_delete (int n, int bwd); 69 static int db_inputchar (int c); 70 static void db_putnchars (int c, int count); 71 static void db_putstring (char *s, int count); 72 73 void 74 db_putstring(char *s, int count) 75 { 76 while (--count >= 0) 77 cnputc(*s++); 78 } 79 80 void 81 db_putnchars(int c, int count) 82 { 83 while (--count >= 0) 84 cnputc(c); 85 } 86 87 /* 88 * Delete N characters, forward or backward 89 */ 90 #define DEL_FWD 0 91 #define DEL_BWD 1 92 void 93 db_delete(int n, int bwd) 94 { 95 char *p; 96 97 if (bwd) { 98 db_lc -= n; 99 db_putnchars(BACKUP, n); 100 } 101 for (p = db_lc; p < db_le-n; p++) { 102 *p = *(p+n); 103 cnputc(*p); 104 } 105 db_putnchars(BLANK, n); 106 db_putnchars(BACKUP, db_le - db_lc); 107 db_le -= n; 108 } 109 110 /* returns TRUE at end-of-line */ 111 int 112 db_inputchar(int c) 113 { 114 static int escstate; 115 116 if (escstate == 1) { 117 /* ESC seen, look for [ or O */ 118 if (c == '[' || c == 'O') 119 escstate++; 120 else 121 escstate = 0; /* re-init state machine */ 122 return (0); 123 } else if (escstate == 2) { 124 escstate = 0; 125 /* 126 * If a valid cursor key has been found, translate 127 * into an emacs-style control key, and fall through. 128 * Otherwise, drop off. 129 */ 130 switch (c) { 131 case 'A': /* up */ 132 c = CTRL('p'); 133 break; 134 case 'B': /* down */ 135 c = CTRL('n'); 136 break; 137 case 'C': /* right */ 138 c = CTRL('f'); 139 break; 140 case 'D': /* left */ 141 c = CTRL('b'); 142 break; 143 default: 144 return (0); 145 } 146 } 147 148 switch (c) { 149 case CTRL('['): 150 escstate = 1; 151 break; 152 case CTRL('b'): 153 /* back up one character */ 154 if (db_lc > db_lbuf_start) { 155 cnputc(BACKUP); 156 db_lc--; 157 } 158 break; 159 case CTRL('f'): 160 /* forward one character */ 161 if (db_lc < db_le) { 162 cnputc(*db_lc); 163 db_lc++; 164 } 165 break; 166 case CTRL('a'): 167 /* beginning of line */ 168 while (db_lc > db_lbuf_start) { 169 cnputc(BACKUP); 170 db_lc--; 171 } 172 break; 173 case CTRL('e'): 174 /* end of line */ 175 while (db_lc < db_le) { 176 cnputc(*db_lc); 177 db_lc++; 178 } 179 break; 180 case CTRL('h'): 181 case 0177: 182 /* erase previous character */ 183 if (db_lc > db_lbuf_start) 184 db_delete(1, DEL_BWD); 185 break; 186 case CTRL('d'): 187 /* erase next character */ 188 if (db_lc < db_le) 189 db_delete(1, DEL_FWD); 190 break; 191 case CTRL('u'): 192 /* kill entire line: */ 193 /* at first, delete to beginning of line */ 194 if (db_lc > db_lbuf_start) 195 db_delete(db_lc - db_lbuf_start, DEL_BWD); 196 /* FALLTHROUGH */ 197 case CTRL('k'): 198 /* delete to end of line */ 199 if (db_lc < db_le) 200 db_delete(db_le - db_lc, DEL_FWD); 201 break; 202 case CTRL('t'): 203 /* twiddle last 2 characters */ 204 if (db_lc >= db_lbuf_start + 2) { 205 c = db_lc[-2]; 206 db_lc[-2] = db_lc[-1]; 207 db_lc[-1] = c; 208 cnputc(BACKUP); 209 cnputc(BACKUP); 210 cnputc(db_lc[-2]); 211 cnputc(db_lc[-1]); 212 } 213 break; 214 case CTRL('r'): 215 db_putstring("^R\n", 3); 216 redraw: 217 if (db_le > db_lbuf_start) { 218 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 219 db_putnchars(BACKUP, db_le - db_lc); 220 } 221 break; 222 case CTRL('p'): 223 /* Make previous history line the active one. */ 224 if (db_lhistcur >= 0) { 225 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 226 db_lbuf_start, db_lhistlsize); 227 db_lhistcur--; 228 goto hist_redraw; 229 } 230 break; 231 case CTRL('n'): 232 /* Make next history line the active one. */ 233 if (db_lhistcur < db_lhistidx - 1) { 234 db_lhistcur += 2; 235 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 236 db_lbuf_start, db_lhistlsize); 237 } else { 238 /* 239 * ^N through tail of history, reset the 240 * buffer to zero length. 241 */ 242 *db_lbuf_start = '\0'; 243 db_lhistcur = db_lhistidx; 244 } 245 246 hist_redraw: 247 db_putnchars(BACKUP, db_le - db_lbuf_start); 248 db_putnchars(BLANK, db_le - db_lbuf_start); 249 db_putnchars(BACKUP, db_le - db_lbuf_start); 250 db_le = index(db_lbuf_start, '\0'); 251 if (db_le[-1] == '\r' || db_le[-1] == '\n') 252 *--db_le = '\0'; 253 db_lc = db_le; 254 goto redraw; 255 256 case -1: 257 /* 258 * eek! the console returned eof. 259 * probably that means we HAVE no console.. we should try bail 260 * XXX 261 */ 262 return (0); 263 case '\n': 264 case '\r': 265 *db_le++ = c; 266 return (1); 267 default: 268 if (db_le == db_lbuf_end) { 269 cnputc('\007'); 270 } 271 else if (c >= ' ' && c <= '~') { 272 char *p; 273 274 for (p = db_le; p > db_lc; p--) 275 *p = *(p-1); 276 *db_lc++ = c; 277 db_le++; 278 cnputc(c); 279 db_putstring(db_lc, db_le - db_lc); 280 db_putnchars(BACKUP, db_le - db_lc); 281 } 282 break; 283 } 284 return (0); 285 } 286 287 int 288 cnmaygetc(void) 289 { 290 return (-1); 291 } 292 293 int 294 db_readline(char *lstart, int lsize) 295 { 296 if (lsize != db_lhistlsize) { 297 /* 298 * (Re)initialize input line history. Throw away any 299 * existing history. 300 */ 301 db_lhist_nlines = sizeof(db_lhistory) / lsize; 302 db_lhistlsize = lsize; 303 db_lhistidx = -1; 304 } 305 db_lhistcur = db_lhistidx; 306 307 db_force_whitespace(); /* synch output position */ 308 309 db_lbuf_start = lstart; 310 db_lbuf_end = lstart + lsize; 311 db_lc = lstart; 312 db_le = lstart; 313 314 while (!db_inputchar(cngetc())) 315 continue; 316 317 db_printf("\n"); /* synch output position */ 318 *db_le = 0; 319 320 if (db_le - db_lbuf_start > 1) { 321 /* Maintain input line history for non-empty lines. */ 322 if (++db_lhistidx == db_lhist_nlines) { 323 /* Rotate history. */ 324 ovbcopy(db_lhistory + db_lhistlsize, db_lhistory, 325 db_lhistlsize * (db_lhist_nlines - 1)); 326 db_lhistidx--; 327 } 328 bcopy(lstart, db_lhistory + db_lhistidx * db_lhistlsize, 329 db_lhistlsize); 330 } 331 332 return (db_le - db_lbuf_start); 333 } 334 335 void 336 db_check_interrupt(void) 337 { 338 int c; 339 340 c = cnmaygetc(); 341 switch (c) { 342 case -1: /* no character */ 343 return; 344 345 case CTRL('c'): 346 db_error(NULL); 347 /*NOTREACHED*/ 348 349 case CTRL('s'): 350 do { 351 c = cnmaygetc(); 352 if (c == CTRL('c')) 353 db_error(NULL); 354 } while (c != CTRL('q')); 355 break; 356 357 default: 358 /* drop on floor */ 359 break; 360 } 361 } 362