1 /* 2 * Copyright (C) 1984-2012 Mark Nudelman 3 * Modified for use with illumos by Garrett D'Amore. 4 * Copyright 2014 Garrett D'Amore <garrett@damore.org> 5 * 6 * You may distribute under the terms of either the GNU General Public 7 * License or the Less License, as specified in the README file. 8 * 9 * For more information, see the README file. 10 */ 11 12 /* 13 * Routines to decode user commands. 14 * 15 * This is all table driven. 16 * A command table is a sequence of command descriptors. 17 * Each command descriptor is a sequence of bytes with the following format: 18 * <c1><c2>...<cN><0><action> 19 * The characters c1,c2,...,cN are the command string; that is, 20 * the characters which the user must type. 21 * It is terminated by a null <0> byte. 22 * The byte after the null byte is the action code associated 23 * with the command string. 24 * If an action byte is OR-ed with A_EXTRA, this indicates 25 * that the option byte is followed by an extra string. 26 * 27 * There may be many command tables. 28 * The first (default) table is built-in. 29 * Other tables are read in from "lesskey" files. 30 * All the tables are linked together and are searched in order. 31 */ 32 33 #include "cmd.h" 34 #include "less.h" 35 #include "lesskey.h" 36 37 extern int erase_char, erase2_char, kill_char; 38 extern int secure, less_is_more; 39 40 #define SK(k) \ 41 SK_SPECIAL_KEY, (k), 6, 1, 1, 1 42 /* 43 * Command table is ordered roughly according to expected 44 * frequency of use, so the common commands are near the beginning. 45 */ 46 47 static unsigned char cmdtable[] = 48 { 49 '\r', 0, A_F_LINE, 50 '\n', 0, A_F_LINE, 51 'e', 0, A_F_LINE, 52 'j', 0, A_F_LINE, 53 SK(SK_DOWN_ARROW), 0, A_F_LINE, 54 CONTROL('E'), 0, A_F_LINE, 55 CONTROL('N'), 0, A_F_LINE, 56 'k', 0, A_B_LINE, 57 'y', 0, A_B_LINE, 58 CONTROL('Y'), 0, A_B_LINE, 59 SK(SK_CONTROL_K), 0, A_B_LINE, 60 CONTROL('P'), 0, A_B_LINE, 61 SK(SK_UP_ARROW), 0, A_B_LINE, 62 'J', 0, A_FF_LINE, 63 'K', 0, A_BF_LINE, 64 'Y', 0, A_BF_LINE, 65 'd', 0, A_F_SCROLL, 66 CONTROL('D'), 0, A_F_SCROLL, 67 'u', 0, A_B_SCROLL, 68 CONTROL('U'), 0, A_B_SCROLL, 69 ' ', 0, A_F_SCREEN, 70 'f', 0, A_F_SCREEN, 71 CONTROL('F'), 0, A_F_SCREEN, 72 CONTROL('V'), 0, A_F_SCREEN, 73 SK(SK_PAGE_DOWN), 0, A_F_SCREEN, 74 'b', 0, A_B_SCREEN, 75 CONTROL('B'), 0, A_B_SCREEN, 76 ESC, 'v', 0, A_B_SCREEN, 77 SK(SK_PAGE_UP), 0, A_B_SCREEN, 78 'z', 0, A_F_WINDOW, 79 'w', 0, A_B_WINDOW, 80 ESC, ' ', 0, A_FF_SCREEN, 81 'F', 0, A_F_FOREVER, 82 ESC, 'F', 0, A_F_UNTIL_HILITE, 83 'R', 0, A_FREPAINT, 84 'r', 0, A_REPAINT, 85 CONTROL('R'), 0, A_REPAINT, 86 CONTROL('L'), 0, A_REPAINT, 87 ESC, 'u', 0, A_UNDO_SEARCH, 88 'g', 0, A_GOLINE, 89 SK(SK_HOME), 0, A_GOLINE, 90 '<', 0, A_GOLINE, 91 ESC, '<', 0, A_GOLINE, 92 'p', 0, A_PERCENT, 93 '%', 0, A_PERCENT, 94 ESC, '[', 0, A_LSHIFT, 95 ESC, ']', 0, A_RSHIFT, 96 ESC, '(', 0, A_LSHIFT, 97 ESC, ')', 0, A_RSHIFT, 98 SK(SK_RIGHT_ARROW), 0, A_RSHIFT, 99 SK(SK_LEFT_ARROW), 0, A_LSHIFT, 100 '{', 0, A_F_BRACKET|A_EXTRA, '{', '}', 0, 101 '}', 0, A_B_BRACKET|A_EXTRA, '{', '}', 0, 102 '(', 0, A_F_BRACKET|A_EXTRA, '(', ')', 0, 103 ')', 0, A_B_BRACKET|A_EXTRA, '(', ')', 0, 104 '[', 0, A_F_BRACKET|A_EXTRA, '[', ']', 0, 105 ']', 0, A_B_BRACKET|A_EXTRA, '[', ']', 0, 106 ESC, CONTROL('F'), 0, A_F_BRACKET, 107 ESC, CONTROL('B'), 0, A_B_BRACKET, 108 'G', 0, A_GOEND, 109 ESC, '>', 0, A_GOEND, 110 '>', 0, A_GOEND, 111 SK(SK_END), 0, A_GOEND, 112 'P', 0, A_GOPOS, 113 114 '0', 0, A_DIGIT, 115 '1', 0, A_DIGIT, 116 '2', 0, A_DIGIT, 117 '3', 0, A_DIGIT, 118 '4', 0, A_DIGIT, 119 '5', 0, A_DIGIT, 120 '6', 0, A_DIGIT, 121 '7', 0, A_DIGIT, 122 '8', 0, A_DIGIT, 123 '9', 0, A_DIGIT, 124 '.', 0, A_DIGIT, 125 126 '=', 0, A_STAT, 127 CONTROL('G'), 0, A_STAT, 128 ':', 'f', 0, A_STAT, 129 '/', 0, A_F_SEARCH, 130 '?', 0, A_B_SEARCH, 131 ESC, '/', 0, A_F_SEARCH|A_EXTRA, '*', 0, 132 ESC, '?', 0, A_B_SEARCH|A_EXTRA, '*', 0, 133 'n', 0, A_AGAIN_SEARCH, 134 ESC, 'n', 0, A_T_AGAIN_SEARCH, 135 'N', 0, A_REVERSE_SEARCH, 136 ESC, 'N', 0, A_T_REVERSE_SEARCH, 137 '&', 0, A_FILTER, 138 'm', 0, A_SETMARK, 139 '\'', 0, A_GOMARK, 140 CONTROL('X'), CONTROL('X'), 0, A_GOMARK, 141 'E', 0, A_EXAMINE, 142 ':', 'e', 0, A_EXAMINE, 143 CONTROL('X'), CONTROL('V'), 0, A_EXAMINE, 144 ':', 'n', 0, A_NEXT_FILE, 145 ':', 'p', 0, A_PREV_FILE, 146 't', 0, A_NEXT_TAG, 147 'T', 0, A_PREV_TAG, 148 ':', 'x', 0, A_INDEX_FILE, 149 ':', 'd', 0, A_REMOVE_FILE, 150 ':', 't', 0, A_OPT_TOGGLE|A_EXTRA, 't', 0, 151 '|', 0, A_PIPE, 152 'v', 0, A_VISUAL, 153 '+', 0, A_FIRSTCMD, 154 155 'H', 0, A_HELP, 156 'h', 0, A_HELP, 157 SK(SK_F1), 0, A_HELP, 158 'V', 0, A_VERSION, 159 'q', 0, A_QUIT, 160 'Q', 0, A_QUIT, 161 ':', 'q', 0, A_QUIT, 162 ':', 'Q', 0, A_QUIT, 163 'Z', 'Z', 0, A_QUIT 164 }; 165 166 static unsigned char lesstable[] = { 167 '-', 0, A_OPT_TOGGLE, 168 's', 0, A_OPT_TOGGLE|A_EXTRA, 'o', 0, 169 '_', 0, A_DISP_OPTION 170 }; 171 172 static unsigned char moretable[] = { 173 's', 0, A_F_SKIP 174 }; 175 176 static unsigned char edittable[] = 177 { 178 '\t', 0, EC_F_COMPLETE, /* TAB */ 179 '\17', 0, EC_B_COMPLETE, /* BACKTAB */ 180 SK(SK_BACKTAB), 0, EC_B_COMPLETE, /* BACKTAB */ 181 ESC, '\t', 0, EC_B_COMPLETE, /* ESC TAB */ 182 CONTROL('L'), 0, EC_EXPAND, /* CTRL-L */ 183 CONTROL('V'), 0, EC_LITERAL, /* BACKSLASH */ 184 CONTROL('A'), 0, EC_LITERAL, /* BACKSLASH */ 185 ESC, 'l', 0, EC_RIGHT, /* ESC l */ 186 SK(SK_RIGHT_ARROW), 0, EC_RIGHT, /* RIGHTARROW */ 187 ESC, 'h', 0, EC_LEFT, /* ESC h */ 188 SK(SK_LEFT_ARROW), 0, EC_LEFT, /* LEFTARROW */ 189 ESC, 'b', 0, EC_W_LEFT, /* ESC b */ 190 ESC, SK(SK_LEFT_ARROW), 0, EC_W_LEFT, /* ESC LEFTARROW */ 191 SK(SK_CTL_LEFT_ARROW), 0, EC_W_LEFT, /* CTRL-LEFTARROW */ 192 ESC, 'w', 0, EC_W_RIGHT, /* ESC w */ 193 ESC, SK(SK_RIGHT_ARROW), 0, EC_W_RIGHT, /* ESC RIGHTARROW */ 194 SK(SK_CTL_RIGHT_ARROW), 0, EC_W_RIGHT, /* CTRL-RIGHTARROW */ 195 ESC, 'i', 0, EC_INSERT, /* ESC i */ 196 SK(SK_INSERT), 0, EC_INSERT, /* INSERT */ 197 ESC, 'x', 0, EC_DELETE, /* ESC x */ 198 SK(SK_DELETE), 0, EC_DELETE, /* DELETE */ 199 ESC, 'X', 0, EC_W_DELETE, /* ESC X */ 200 ESC, SK(SK_DELETE), 0, EC_W_DELETE, /* ESC DELETE */ 201 SK(SK_CTL_DELETE), 0, EC_W_DELETE, /* CTRL-DELETE */ 202 SK(SK_CTL_BACKSPACE), 0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */ 203 ESC, '\b', 0, EC_W_BACKSPACE, /* ESC BACKSPACE */ 204 ESC, '0', 0, EC_HOME, /* ESC 0 */ 205 SK(SK_HOME), 0, EC_HOME, /* HOME */ 206 ESC, '$', 0, EC_END, /* ESC $ */ 207 SK(SK_END), 0, EC_END, /* END */ 208 ESC, 'k', 0, EC_UP, /* ESC k */ 209 SK(SK_UP_ARROW), 0, EC_UP, /* UPARROW */ 210 ESC, 'j', 0, EC_DOWN, /* ESC j */ 211 SK(SK_DOWN_ARROW), 0, EC_DOWN, /* DOWNARROW */ 212 CONTROL('G'), 0, EC_ABORT, /* CTRL-G */ 213 }; 214 215 /* 216 * Structure to support a list of command tables. 217 */ 218 struct tablelist { 219 struct tablelist *t_next; 220 char *t_start; 221 char *t_end; 222 }; 223 224 /* 225 * List of command tables and list of line-edit tables. 226 */ 227 static struct tablelist *list_fcmd_tables = NULL; 228 static struct tablelist *list_ecmd_tables = NULL; 229 static struct tablelist *list_var_tables = NULL; 230 static struct tablelist *list_sysvar_tables = NULL; 231 232 233 /* 234 * Expand special key abbreviations in a command table. 235 */ 236 static void 237 expand_special_keys(char *table, int len) 238 { 239 char *fm; 240 char *to; 241 int a; 242 char *repl; 243 int klen; 244 245 for (fm = table; fm < table + len; ) { 246 /* 247 * Rewrite each command in the table with any 248 * special key abbreviations expanded. 249 */ 250 for (to = fm; *fm != '\0'; ) { 251 if (*fm != SK_SPECIAL_KEY) { 252 *to++ = *fm++; 253 continue; 254 } 255 /* 256 * After SK_SPECIAL_KEY, next byte is the type 257 * of special key (one of the SK_* contants), 258 * and the byte after that is the number of bytes, 259 * N, reserved by the abbreviation (including the 260 * SK_SPECIAL_KEY and key type bytes). 261 * Replace all N bytes with the actual bytes 262 * output by the special key on this terminal. 263 */ 264 repl = special_key_str(fm[1]); 265 klen = fm[2] & 0377; 266 fm += klen; 267 if (repl == NULL || strlen(repl) > klen) 268 repl = "\377"; 269 while (*repl != '\0') 270 *to++ = *repl++; 271 } 272 *to++ = '\0'; 273 /* 274 * Fill any unused bytes between end of command and 275 * the action byte with A_SKIP. 276 */ 277 while (to <= fm) 278 *to++ = A_SKIP; 279 fm++; 280 a = *fm++ & 0377; 281 if (a & A_EXTRA) { 282 while (*fm++ != '\0') 283 continue; 284 } 285 } 286 } 287 288 /* 289 * Initialize the command lists. 290 */ 291 void 292 init_cmds(void) 293 { 294 /* 295 * Add the default command tables. 296 */ 297 add_fcmd_table((char *)cmdtable, sizeof (cmdtable)); 298 add_ecmd_table((char *)edittable, sizeof (edittable)); 299 if (less_is_more) { 300 add_fcmd_table((char *)moretable, sizeof (moretable)); 301 return; 302 } else { 303 add_fcmd_table((char *)lesstable, sizeof (lesstable)); 304 } 305 306 /* 307 * Try to add the tables in the system lesskey file. 308 */ 309 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1); 310 /* 311 * Try to add the tables in the standard lesskey file "$HOME/.less". 312 */ 313 add_hometable("LESSKEY", LESSKEYFILE, 0); 314 } 315 316 /* 317 * Add a command table. 318 */ 319 static int 320 add_cmd_table(struct tablelist **tlist, char *buf, int len) 321 { 322 struct tablelist *t; 323 324 if (len == 0) 325 return (0); 326 /* 327 * Allocate a tablelist structure, initialize it, 328 * and link it into the list of tables. 329 */ 330 if ((t = calloc(1, sizeof (struct tablelist))) == NULL) { 331 return (-1); 332 } 333 expand_special_keys(buf, len); 334 t->t_start = buf; 335 t->t_end = buf + len; 336 t->t_next = *tlist; 337 *tlist = t; 338 return (0); 339 } 340 341 /* 342 * Add a command table. 343 */ 344 void 345 add_fcmd_table(char *buf, int len) 346 { 347 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0) 348 error("Warning: some commands disabled", NULL); 349 } 350 351 /* 352 * Add an editing command table. 353 */ 354 void 355 add_ecmd_table(char *buf, int len) 356 { 357 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0) 358 error("Warning: some edit commands disabled", NULL); 359 } 360 361 /* 362 * Add an environment variable table. 363 */ 364 static void 365 add_var_table(struct tablelist **tlist, char *buf, int len) 366 { 367 if (add_cmd_table(tlist, buf, len) < 0) 368 error("Warning: environment variables from " 369 "lesskey file unavailable", NULL); 370 } 371 372 /* 373 * Search a single command table for the command string in cmd. 374 */ 375 static int 376 cmd_search(const char *cmd, char *table, char *endtable, char **sp) 377 { 378 char *p; 379 const char *q; 380 int a; 381 382 *sp = NULL; 383 for (p = table, q = cmd; p < endtable; p++, q++) { 384 if (*p == *q) { 385 /* 386 * Current characters match. 387 * If we're at the end of the string, we've found it. 388 * Return the action code, which is the character 389 * after the null at the end of the string 390 * in the command table. 391 */ 392 if (*p == '\0') { 393 a = *++p & 0377; 394 while (a == A_SKIP) 395 a = *++p & 0377; 396 if (a == A_END_LIST) { 397 /* 398 * We get here only if the original 399 * cmd string passed in was empty (""). 400 * I don't think that can happen, 401 * but just in case ... 402 */ 403 return (A_UINVALID); 404 } 405 /* 406 * Check for an "extra" string. 407 */ 408 if (a & A_EXTRA) { 409 *sp = ++p; 410 a &= ~A_EXTRA; 411 } 412 return (a); 413 } 414 } else if (*q == '\0') { 415 /* 416 * Hit the end of the user's command, 417 * but not the end of the string in the command table. 418 * The user's command is incomplete. 419 */ 420 return (A_PREFIX); 421 } else { 422 /* 423 * Not a match. 424 * Skip ahead to the next command in the 425 * command table, and reset the pointer 426 * to the beginning of the user's command. 427 */ 428 if (*p == '\0' && p[1] == A_END_LIST) { 429 /* 430 * A_END_LIST is a special marker that tells 431 * us to abort the cmd search. 432 */ 433 return (A_UINVALID); 434 } 435 while (*p++ != '\0') 436 continue; 437 while (*p == A_SKIP) 438 p++; 439 if (*p & A_EXTRA) 440 while (*++p != '\0') 441 continue; 442 q = cmd-1; 443 } 444 } 445 /* 446 * No match found in the entire command table. 447 */ 448 return (A_INVALID); 449 } 450 451 /* 452 * Decode a command character and return the associated action. 453 * The "extra" string, if any, is returned in sp. 454 */ 455 static int 456 cmd_decode(struct tablelist *tlist, const char *cmd, char **sp) 457 { 458 struct tablelist *t; 459 int action = A_INVALID; 460 461 /* 462 * Search thru all the command tables. 463 * Stop when we find an action which is not A_INVALID. 464 */ 465 for (t = tlist; t != NULL; t = t->t_next) { 466 action = cmd_search(cmd, t->t_start, t->t_end, sp); 467 if (action != A_INVALID) 468 break; 469 } 470 if (action == A_UINVALID) 471 action = A_INVALID; 472 return (action); 473 } 474 475 /* 476 * Decode a command from the cmdtables list. 477 */ 478 int 479 fcmd_decode(const char *cmd, char **sp) 480 { 481 return (cmd_decode(list_fcmd_tables, cmd, sp)); 482 } 483 484 /* 485 * Decode a command from the edittables list. 486 */ 487 int 488 ecmd_decode(const char *cmd, char **sp) 489 { 490 return (cmd_decode(list_ecmd_tables, cmd, sp)); 491 } 492 493 /* 494 * Get the value of an environment variable. 495 * Looks first in the lesskey file, then in the real environment. 496 */ 497 char * 498 lgetenv(char *var) 499 { 500 int a; 501 char *s; 502 503 /* 504 * Ignore lookups of any LESS* setting when we are more, and ignore 505 * the less key files 506 */ 507 if (less_is_more) { 508 if (strncmp(var, "LESS", 4) == 0) { 509 return (NULL); 510 } 511 return (getenv(var)); 512 } 513 a = cmd_decode(list_var_tables, var, &s); 514 if (a == EV_OK) 515 return (s); 516 s = getenv(var); 517 if (s != NULL && *s != '\0') 518 return (s); 519 a = cmd_decode(list_sysvar_tables, var, &s); 520 if (a == EV_OK) 521 return (s); 522 return (NULL); 523 } 524 525 /* 526 * Get an "integer" from a lesskey file. 527 * Integers are stored in a funny format: 528 * two bytes, low order first, in radix KRADIX. 529 */ 530 static int 531 gint(char **sp) 532 { 533 int n; 534 535 n = *(*sp)++; 536 n += *(*sp)++ * KRADIX; 537 return (n); 538 } 539 540 /* 541 * Process an old (pre-v241) lesskey file. 542 */ 543 static int 544 old_lesskey(char *buf, int len) 545 { 546 /* 547 * Old-style lesskey file. 548 * The file must end with either 549 * ..,cmd,0,action 550 * or ...,cmd,0,action|A_EXTRA,string,0 551 * So the last byte or the second to last byte must be zero. 552 */ 553 if (buf[len-1] != '\0' && buf[len-2] != '\0') 554 return (-1); 555 add_fcmd_table(buf, len); 556 return (0); 557 } 558 559 /* 560 * Process a new (post-v241) lesskey file. 561 */ 562 static int 563 new_lesskey(char *buf, int len, int sysvar) 564 { 565 char *p; 566 int c; 567 int n; 568 569 /* 570 * New-style lesskey file. 571 * Extract the pieces. 572 */ 573 if (buf[len-3] != C0_END_LESSKEY_MAGIC || 574 buf[len-2] != C1_END_LESSKEY_MAGIC || 575 buf[len-1] != C2_END_LESSKEY_MAGIC) 576 return (-1); 577 p = buf + 4; 578 for (;;) { 579 c = *p++; 580 switch (c) { 581 case CMD_SECTION: 582 n = gint(&p); 583 add_fcmd_table(p, n); 584 p += n; 585 break; 586 case EDIT_SECTION: 587 n = gint(&p); 588 add_ecmd_table(p, n); 589 p += n; 590 break; 591 case VAR_SECTION: 592 n = gint(&p); 593 add_var_table((sysvar) ? 594 &list_sysvar_tables : &list_var_tables, p, n); 595 p += n; 596 break; 597 case END_SECTION: 598 return (0); 599 default: 600 /* 601 * Unrecognized section type. 602 */ 603 return (-1); 604 } 605 } 606 } 607 608 /* 609 * Set up a user command table, based on a "lesskey" file. 610 */ 611 int 612 lesskey(char *filename, int sysvar) 613 { 614 char *buf; 615 off_t len; 616 long n; 617 int f; 618 619 if (secure) 620 return (1); 621 /* 622 * Try to open the lesskey file. 623 */ 624 filename = shell_unquote(filename); 625 f = open(filename, O_RDONLY); 626 free(filename); 627 if (f < 0) 628 return (1); 629 630 /* 631 * Read the file into a buffer. 632 * We first figure out the size of the file and allocate space for it. 633 * {{ Minimal error checking is done here. 634 * A garbage .less file will produce strange results. 635 * To avoid a large amount of error checking code here, we 636 * rely on the lesskey program to generate a good .less file. }} 637 */ 638 len = filesize(f); 639 if (len == -1 || len < 3) { 640 /* 641 * Bad file (valid file must have at least 3 chars). 642 */ 643 (void) close(f); 644 return (-1); 645 } 646 if ((buf = calloc((int)len, sizeof (char))) == NULL) { 647 (void) close(f); 648 return (-1); 649 } 650 if (lseek(f, (off_t)0, SEEK_SET) == (off_t)-1) { 651 free(buf); 652 (void) close(f); 653 return (-1); 654 } 655 n = read(f, buf, (unsigned int) len); 656 close(f); 657 if (n != len) { 658 free(buf); 659 return (-1); 660 } 661 662 /* 663 * Figure out if this is an old-style (before version 241) 664 * or new-style lesskey file format. 665 */ 666 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC || 667 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC) 668 return (old_lesskey(buf, (int)len)); 669 return (new_lesskey(buf, (int)len, sysvar)); 670 } 671 672 /* 673 * Add the standard lesskey file "$HOME/.less" 674 */ 675 void 676 add_hometable(char *envname, char *def_filename, int sysvar) 677 { 678 char *filename; 679 PARG parg; 680 681 if (envname != NULL && (filename = lgetenv(envname)) != NULL) 682 filename = estrdup(filename); 683 else if (sysvar) 684 filename = estrdup(def_filename); 685 else 686 filename = homefile(def_filename); 687 if (filename == NULL) 688 return; 689 if (lesskey(filename, sysvar) < 0) { 690 parg.p_string = filename; 691 error("Cannot use lesskey file \"%s\"", &parg); 692 } 693 free(filename); 694 } 695 696 /* 697 * See if a char is a special line-editing command. 698 */ 699 int 700 editchar(int c, int flags) 701 { 702 int action; 703 int nch; 704 char *s; 705 char usercmd[MAX_CMDLEN+1]; 706 707 /* 708 * An editing character could actually be a sequence of characters; 709 * for example, an escape sequence sent by pressing the uparrow key. 710 * To match the editing string, we use the command decoder 711 * but give it the edit-commands command table 712 * This table is constructed to match the user's keyboard. 713 */ 714 if (c == erase_char || c == erase2_char) 715 return (EC_BACKSPACE); 716 if (c == kill_char) 717 return (EC_LINEKILL); 718 719 /* 720 * Collect characters in a buffer. 721 * Start with the one we have, and get more if we need them. 722 */ 723 nch = 0; 724 do { 725 if (nch > 0) 726 c = getcc(); 727 usercmd[nch] = (char)c; 728 usercmd[nch+1] = '\0'; 729 nch++; 730 action = ecmd_decode(usercmd, &s); 731 } while (action == A_PREFIX); 732 733 if (flags & EC_NORIGHTLEFT) { 734 switch (action) { 735 case EC_RIGHT: 736 case EC_LEFT: 737 action = A_INVALID; 738 break; 739 } 740 } 741 if (flags & EC_NOHISTORY) { 742 /* 743 * The caller says there is no history list. 744 * Reject any history-manipulation action. 745 */ 746 switch (action) { 747 case EC_UP: 748 case EC_DOWN: 749 action = A_INVALID; 750 break; 751 } 752 } 753 if (flags & EC_NOCOMPLETE) { 754 /* 755 * The caller says we don't want any filename completion cmds. 756 * Reject them. 757 */ 758 switch (action) { 759 case EC_F_COMPLETE: 760 case EC_B_COMPLETE: 761 case EC_EXPAND: 762 action = A_INVALID; 763 break; 764 } 765 } 766 if ((flags & EC_PEEK) || action == A_INVALID) { 767 /* 768 * We're just peeking, or we didn't understand the command. 769 * Unget all the characters we read in the loop above. 770 * This does NOT include the original character that was 771 * passed in as a parameter. 772 */ 773 while (nch > 1) { 774 ungetcc(usercmd[--nch]); 775 } 776 } else { 777 if (s != NULL) 778 ungetsc(s); 779 } 780 return (action); 781 } 782