db_input.c revision 21673
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: head/sys/ddb/db_input.c 21673 1997-01-14 07:20:47Z jkh $ 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 */ 52static char * db_lbuf_start; /* start of input line buffer */ 53static char * db_lbuf_end; /* end of input line buffer */ 54static char * db_lc; /* current character */ 55static char * db_le; /* one past last character */ 56 57/* 58 * Simple input line history support. 59 */ 60static char * db_lhistory; 61static 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 69static int cnmaygetc __P((void)); 70static void db_delete __P((int n, int bwd)); 71static int db_inputchar __P((int c)); 72static void db_putnchars __P((int c, int count)); 73static void db_putstring __P((char *s, int count)); 74 75void 76db_putstring(s, count) 77 char *s; 78 int count; 79{ 80 while (--count >= 0) 81 cnputc(*s++); 82} 83 84void 85db_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 98void 99db_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 */ 119int 120db_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 -1: 223 /* 224 * eek! the console returned eof. 225 * probably that means we HAVE no console.. we should try bail 226 * XXX 227 */ 228 c = '\r'; 229 case '\n': 230 case '\r': 231 *db_le++ = c; 232 return (1); 233 default: 234 if (db_le == db_lbuf_end) { 235 cnputc('\007'); 236 } 237 else if (c >= ' ' && c <= '~') { 238 register char *p; 239 240 for (p = db_le; p > db_lc; p--) 241 *p = *(p-1); 242 *db_lc++ = c; 243 db_le++; 244 cnputc(c); 245 db_putstring(db_lc, db_le - db_lc); 246 db_putnchars(BACKUP, db_le - db_lc); 247 } 248 break; 249 } 250 return (0); 251} 252 253int 254cnmaygetc() 255{ 256 return (-1); 257} 258 259int 260db_readline(lstart, lsize) 261 char * lstart; 262 int lsize; 263{ 264 if (db_lhistory && lsize != db_lhistlsize) { 265 /* Should not happen, but to be sane, throw history away. */ 266 FREE(db_lhistory, M_TEMP); 267 db_lhistory = 0; 268 } 269 if (db_lhistory == 0) { 270 /* Initialize input line history. */ 271 db_lhistlsize = lsize; 272 db_lhistidx = -1; 273 MALLOC(db_lhistory, char *, lsize * DB_LHIST_NLINES, 274 M_TEMP, M_NOWAIT); 275 } 276 db_lhistcur = db_lhistidx; 277 278 db_force_whitespace(); /* synch output position */ 279 280 db_lbuf_start = lstart; 281 db_lbuf_end = lstart + lsize; 282 db_lc = lstart; 283 db_le = lstart; 284 285 while (!db_inputchar(cngetc())) 286 continue; 287 288 db_printf("\n"); /* synch output position */ 289 *db_le = 0; 290 291 if (db_le - db_lbuf_start > 1) { 292 /* Maintain input line history for non-empty lines. */ 293 if (++db_lhistidx == DB_LHIST_NLINES) { 294 /* Rotate history. */ 295 ovbcopy(db_lhistory + db_lhistlsize, db_lhistory, 296 db_lhistlsize * (DB_LHIST_NLINES - 1)); 297 db_lhistidx--; 298 } 299 bcopy(lstart, db_lhistory + (db_lhistidx * db_lhistlsize), 300 db_lhistlsize); 301 } 302 303 return (db_le - db_lbuf_start); 304} 305 306void 307db_check_interrupt() 308{ 309 register int c; 310 311 c = cnmaygetc(); 312 switch (c) { 313 case -1: /* no character */ 314 return; 315 316 case CTRL('c'): 317 db_error((char *)0); 318 /*NOTREACHED*/ 319 320 case CTRL('s'): 321 do { 322 c = cnmaygetc(); 323 if (c == CTRL('c')) 324 db_error((char *)0); 325 } while (c != CTRL('q')); 326 break; 327 328 default: 329 /* drop on floor */ 330 break; 331 } 332} 333 334/* called from kdb_trap in db_interface.c */ 335void 336cnpollc (flag) 337 int flag; 338{ 339} 340