db_input.c revision 17495
1139790Simp/* 266458Sdfr * Mach Operating System 366458Sdfr * Copyright (c) 1991,1990 Carnegie Mellon University 466458Sdfr * All Rights Reserved. 566458Sdfr * 666458Sdfr * Permission to use, copy, modify and distribute this software and its 766458Sdfr * documentation is hereby granted, provided that both the copyright 866458Sdfr * notice and this permission notice appear in all copies of the 966458Sdfr * software, derivative works or modified versions, and any portions 1066458Sdfr * thereof, and that both notices appear in supporting documentation. 1166458Sdfr * 1266458Sdfr * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 1366458Sdfr * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 1466458Sdfr * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 1566458Sdfr * 1666458Sdfr * Carnegie Mellon requests users of this software to return to 1766458Sdfr * 1866458Sdfr * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 1966458Sdfr * School of Computer Science 2066458Sdfr * Carnegie Mellon University 2166458Sdfr * Pittsburgh PA 15213-3890 2266458Sdfr * 2366458Sdfr * any improvements or extensions that they make and grant Carnegie the 2466458Sdfr * rights to redistribute these changes. 2566458Sdfr * 2666458Sdfr * $Id: db_input.c,v 1.13 1996/05/08 04:28:34 gpalmer Exp $ 2766458Sdfr */ 2866458Sdfr 2966458Sdfr/* 3066458Sdfr * Author: David B. Golub, Carnegie Mellon University 3166458Sdfr * Date: 7/90 3266458Sdfr */ 3366458Sdfr 3466458Sdfr#include <sys/param.h> 3566458Sdfr#include <sys/malloc.h> 3666458Sdfr#include <sys/systm.h> 37178296Smarcel 38178296Smarcel#include <machine/cons.h> 3966458Sdfr 4066458Sdfr#include <ddb/ddb.h> 41178296Smarcel#include <ddb/db_output.h> 42178296Smarcel 43178296Smarcel/* 4466458Sdfr * Character input and editing. 45170033Salc */ 46170033Salc 4766458Sdfr/* 48219741Smarcel * We don't track output position while editing input, 4966458Sdfr * since input always ends with a new-line. We just 5066458Sdfr * reset the line position at the end. 5166458Sdfr */ 5266458Sdfrstatic char * db_lbuf_start; /* start of input line buffer */ 5366458Sdfrstatic char * db_lbuf_end; /* end of input line buffer */ 5466458Sdfrstatic char * db_lc; /* current character */ 5566458Sdfrstatic char * db_le; /* one past last character */ 5666458Sdfr 5766458Sdfr/* 5866458Sdfr * Simple input line history support. 5966458Sdfr */ 6066458Sdfrstatic char * db_lhistory; 6166458Sdfrstatic int db_lhistlsize, db_lhistidx, db_lhistcur; 6266458Sdfr#define DB_LHIST_NLINES 10 6366458Sdfr 6466458Sdfr#define CTRL(c) ((c) & 0x1f) 6566458Sdfr#define isspace(c) ((c) == ' ' || (c) == '\t') 6692670Speter#define BLANK ' ' 6766458Sdfr#define BACKUP '\b' 6866458Sdfr 6966458Sdfrstatic int cnmaygetc __P((void)); 7066458Sdfrstatic void db_delete __P((int n, int bwd)); 7166458Sdfrstatic int db_inputchar __P((int c)); 7266458Sdfrstatic void db_putnchars __P((int c, int count)); 73106486Smarcelstatic void db_putstring __P((char *s, int count)); 74106486Smarcel 75106486Smarcelvoid 76106486Smarceldb_putstring(s, count) 77106486Smarcel char *s; 78169291Salc int count; 79169291Salc{ 80169291Salc while (--count >= 0) 81169291Salc cnputc(*s++); 82169291Salc} 83170519Salc 84170519Salcvoid 85170519Salcdb_putnchars(c, count) 86170519Salc int c; 87170519Salc int count; 88170519Salc{ 89172317Salc while (--count >= 0) 90170519Salc cnputc(c); 91170519Salc} 92170519Salc 93170519Salc/* 94172317Salc * Delete N characters, forward or backward 95172317Salc */ 96170519Salc#define DEL_FWD 0 97170519Salc#define DEL_BWD 1 98170519Salcvoid 99170519Salcdb_delete(n, bwd) 100170519Salc int n; 101170519Salc int bwd; 102170519Salc{ 103170519Salc register char *p; 104170519Salc 105170519Salc if (bwd) { 106170519Salc db_lc -= n; 107170519Salc db_putnchars(BACKUP, n); 108170519Salc } 109170519Salc for (p = db_lc; p < db_le-n; p++) { 110170519Salc *p = *(p+n); 111170519Salc cnputc(*p); 112210550Sjhb } 113210550Sjhb db_putnchars(BLANK, n); 114210550Sjhb db_putnchars(BACKUP, db_le - db_lc); 115210550Sjhb db_le -= n; 116210550Sjhb} 117210550Sjhb 118210550Sjhb/* returns TRUE at end-of-line */ 119174938Salcint 120174938Salcdb_inputchar(c) 121174938Salc int c; 122174938Salc{ 123174938Salc switch (c) { 124174938Salc case CTRL('b'): 125174938Salc /* back up one character */ 12696912Smarcel if (db_lc > db_lbuf_start) { 12796912Smarcel cnputc(BACKUP); 128208283Smarcel db_lc--; 12996912Smarcel } 13096912Smarcel break; 13196912Smarcel case CTRL('f'): 13296912Smarcel /* forward one character */ 13396912Smarcel if (db_lc < db_le) { 134219691Smarcel cnputc(*db_lc); 135219691Smarcel db_lc++; 136219691Smarcel } 137219691Smarcel break; 138219691Smarcel case CTRL('a'): 139219691Smarcel /* beginning of line */ 140219691Smarcel while (db_lc > db_lbuf_start) { 141219691Smarcel cnputc(BACKUP); 142219691Smarcel db_lc--; 143219691Smarcel } 144119906Smarcel break; 145119906Smarcel case CTRL('e'): 146119906Smarcel /* end of line */ 147119906Smarcel while (db_lc < db_le) { 148119906Smarcel cnputc(*db_lc); 149119906Smarcel db_lc++; 150119906Smarcel } 151119906Smarcel break; 152119906Smarcel case CTRL('h'): 153119906Smarcel case 0177: 154121268Smarcel /* erase previous character */ 155121268Smarcel if (db_lc > db_lbuf_start) 156119906Smarcel db_delete(1, DEL_BWD); 157219691Smarcel break; 158219691Smarcel case CTRL('d'): 159219691Smarcel /* erase next character */ 160219691Smarcel if (db_lc < db_le) 161219691Smarcel db_delete(1, DEL_FWD); 162219691Smarcel break; 163219691Smarcel case CTRL('k'): 164219691Smarcel /* delete to end of line */ 165219691Smarcel if (db_lc < db_le) 166219691Smarcel db_delete(db_le - db_lc, DEL_FWD); 167219691Smarcel break; 168219691Smarcel case CTRL('t'): 169219691Smarcel /* twiddle last 2 characters */ 170219691Smarcel if (db_lc >= db_lbuf_start + 2) { 171219691Smarcel c = db_lc[-2]; 172219691Smarcel db_lc[-2] = db_lc[-1]; 173219691Smarcel db_lc[-1] = c; 174219691Smarcel cnputc(BACKUP); 175219691Smarcel cnputc(BACKUP); 176219691Smarcel cnputc(db_lc[-2]); 177219691Smarcel cnputc(db_lc[-1]); 178219691Smarcel } 179219691Smarcel break; 180219691Smarcel case CTRL('r'): 181219691Smarcel db_putstring("^R\n", 3); 182219691Smarcel redraw: 183219691Smarcel if (db_le > db_lbuf_start) { 184219691Smarcel db_putstring(db_lbuf_start, db_le - db_lbuf_start); 185219691Smarcel db_putnchars(BACKUP, db_le - db_lc); 186219691Smarcel } 187219691Smarcel break; 188219691Smarcel case CTRL('p'): 189219691Smarcel /* Make previous history line the active one. */ 190219691Smarcel if (db_lhistcur >= 0) { 191219691Smarcel bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 192219691Smarcel db_lbuf_start, db_lhistlsize); 19366458Sdfr db_lhistcur--; 19466458Sdfr goto hist_redraw; 19566458Sdfr } 19666458Sdfr break; 19766458Sdfr case CTRL('n'): 198219741Smarcel /* Make next history line the active one. */ 199115084Smarcel if (db_lhistcur < db_lhistidx - 1) { 200219741Smarcel db_lhistcur += 2; 20166458Sdfr bcopy(db_lhistory + db_lhistcur * db_lhistlsize, 202219741Smarcel db_lbuf_start, db_lhistlsize); 20366458Sdfr } else { 204219741Smarcel /* 20596912Smarcel * ^N through tail of history, reset the 20666458Sdfr * buffer to zero length. 20766458Sdfr */ 20866458Sdfr *db_lbuf_start = '\0'; 20966458Sdfr db_lhistcur = db_lhistidx; 21066458Sdfr } 21166458Sdfr 21266458Sdfr hist_redraw: 213168920Ssepotvin db_putnchars(BACKUP, db_le - db_lbuf_start); 214168920Ssepotvin db_putnchars(BLANK, db_le - db_lbuf_start); 21566458Sdfr db_putnchars(BACKUP, db_le - db_lbuf_start); 21666458Sdfr db_le = index(db_lbuf_start, '\0'); 21766458Sdfr if (db_le[-1] == '\r' || db_le[-1] == '\n') 21866458Sdfr *--db_le = '\0'; 21966458Sdfr db_lc = db_le; 22066458Sdfr goto redraw; 22166458Sdfr 22266458Sdfr case '\n': 22366458Sdfr case '\r': 22466458Sdfr *db_le++ = c; 22566458Sdfr return (1); 226178296Smarcel 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 246int 247cnmaygetc() 248{ 249 return (-1); 250} 251 252int 253db_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 299void 300db_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 */ 328void 329cnpollc (flag) 330 int flag; 331{ 332} 333