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 1.13 1996/05/08 04:28:34 gpalmer 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 switch (c) { 124 case CTRL('b'): 125 /* back up one character */ 126 if (db_lc > db_lbuf_start) { 127 cnputc(BACKUP); 128 db_lc--; 129 } 130 break; 131 case CTRL('f'): 132 /* forward one character */ 133 if (db_lc < db_le) { 134 cnputc(*db_lc); 135 db_lc++; 136 } 137 break; 138 case CTRL('a'): 139 /* beginning of line */ 140 while (db_lc > db_lbuf_start) { 141 cnputc(BACKUP); 142 db_lc--; 143 } 144 break; 145 case CTRL('e'): 146 /* end of line */ 147 while (db_lc < db_le) { 148 cnputc(*db_lc); 149 db_lc++; 150 } 151 break; 152 case CTRL('h'): 153 case 0177: 154 /* erase previous character */ 155 if (db_lc > db_lbuf_start) 156 db_delete(1, DEL_BWD); 157 break; 158 case CTRL('d'): 159 /* erase next character */ 160 if (db_lc < db_le) 161 db_delete(1, DEL_FWD); 162 break; 163 case CTRL('k'): 164 /* delete to end of line */ 165 if (db_lc < db_le) 166 db_delete(db_le - db_lc, DEL_FWD); 167 break; 168 case CTRL('t'): 169 /* twiddle last 2 characters */ 170 if (db_lc >= db_lbuf_start + 2) { 171 c = db_lc[-2]; 172 db_lc[-2] = db_lc[-1]; 173 db_lc[-1] = c; 174 cnputc(BACKUP); 175 cnputc(BACKUP); 176 cnputc(db_lc[-2]); 177 cnputc(db_lc[-1]); 178 } 179 break; 180 case CTRL('r'): 181 db_putstring("^R\n", 3); 182 redraw: 183 if (db_le > db_lbuf_start) { 184 db_putstring(db_lbuf_start, db_le - db_lbuf_start); 185 db_putnchars(BACKUP, db_le - db_lc); 186 } 187 break; 188 case CTRL('p'): 189 /* Make previous history line the active one. */ 190 if (db_lhistcur >= 0) { 191 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 192 db_lbuf_start, db_lhistlsize); 193 db_lhistcur--; 194 goto hist_redraw; 195 } 196 break; 197 case CTRL('n'): 198 /* Make next history line the active one. */ 199 if (db_lhistcur < db_lhistidx - 1) { 200 db_lhistcur += 2; 201 bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 202 db_lbuf_start, db_lhistlsize); 203 } else { 204 /* 205 * ^N through tail of history, reset the 206 * buffer to zero length. 207 */ 208 *db_lbuf_start = '\0'; 209 db_lhistcur = db_lhistidx; 210 } 211 212 hist_redraw: 213 db_putnchars(BACKUP, db_le - db_lbuf_start); 214 db_putnchars(BLANK, db_le - db_lbuf_start); 215 db_putnchars(BACKUP, db_le - db_lbuf_start); 216 db_le = index(db_lbuf_start, '\0'); 217 if (db_le[-1] == '\r' || db_le[-1] == '\n') 218 *--db_le = '\0'; 219 db_lc = db_le; 220 goto redraw; 221 222 case '\n': 223 case '\r': 224 *db_le++ = c; 225 return (1); 226 default: 227 if (db_le == db_lbuf_end) { 228 cnputc('\007'); 229 } 230 else if (c >= ' ' && c <= '~') { 231 register char *p; 232 233 for (p = db_le; p > db_lc; p--) 234 *p = *(p-1); 235 *db_lc++ = c; 236 db_le++; 237 cnputc(c); 238 db_putstring(db_lc, db_le - db_lc); 239 db_putnchars(BACKUP, db_le - db_lc); 240 } 241 break; 242 } 243 return (0); 244 } 245 246 int 247 cnmaygetc() 248 { 249 return (-1); 250 } 251 252 int 253 db_readline(lstart, lsize) 254 char * lstart; 255 int lsize; 256 { 257 if (db_lhistory && lsize != db_lhistlsize) { 258 /* Should not happen, but to be sane, throw history away. */ 259 FREE(db_lhistory, M_TEMP); 260 db_lhistory = 0; 261 } 262 if (db_lhistory == 0) { 263 /* Initialize input line history. */ 264 db_lhistlsize = lsize; 265 db_lhistidx = -1; 266 MALLOC(db_lhistory, char *, lsize * DB_LHIST_NLINES, 267 M_TEMP, M_NOWAIT); 268 } 269 db_lhistcur = db_lhistidx; 270 271 db_force_whitespace(); /* synch output position */ 272 273 db_lbuf_start = lstart; 274 db_lbuf_end = lstart + lsize; 275 db_lc = lstart; 276 db_le = lstart; 277 278 while (!db_inputchar(cngetc())) 279 continue; 280 281 db_printf("\n"); /* synch output position */ 282 *db_le = 0; 283 284 if (db_le - db_lbuf_start > 1) { 285 /* Maintain input line history for non-empty lines. */ 286 if (++db_lhistidx == DB_LHIST_NLINES) { 287 /* Rotate history. */ 288 ovbcopy(db_lhistory + db_lhistlsize, db_lhistory, 289 db_lhistlsize * (DB_LHIST_NLINES - 1)); 290 db_lhistidx--; 291 } 292 bcopy(lstart, db_lhistory + (db_lhistidx * db_lhistlsize), 293 db_lhistlsize); 294 } 295 296 return (db_le - db_lbuf_start); 297 } 298 299 void 300 db_check_interrupt() 301 { 302 register int c; 303 304 c = cnmaygetc(); 305 switch (c) { 306 case -1: /* no character */ 307 return; 308 309 case CTRL('c'): 310 db_error((char *)0); 311 /*NOTREACHED*/ 312 313 case CTRL('s'): 314 do { 315 c = cnmaygetc(); 316 if (c == CTRL('c')) 317 db_error((char *)0); 318 } while (c != CTRL('q')); 319 break; 320 321 default: 322 /* drop on floor */ 323 break; 324 } 325 } 326 327 /* called from kdb_trap in db_interface.c */ 328 void 329 cnpollc (flag) 330 int flag; 331 { 332 } 333