sys/ddb/db_input.c

   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 }