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