decode.c revision 240121
1127664Sbms/* 2127664Sbms * Copyright (C) 1984-2012 Mark Nudelman 3127664Sbms * 4127664Sbms * You may distribute under the terms of either the GNU General Public 5127664Sbms * License or the Less License, as specified in the README file. 6127664Sbms * 7127664Sbms * For more information, see the README file. 8127664Sbms */ 9127664Sbms 10127664Sbms 11127664Sbms/* 12127664Sbms * Routines to decode user commands. 13127664Sbms * 14127664Sbms * This is all table driven. 15127664Sbms * A command table is a sequence of command descriptors. 16127664Sbms * Each command descriptor is a sequence of bytes with the following format: 17127664Sbms * <c1><c2>...<cN><0><action> 18127664Sbms * The characters c1,c2,...,cN are the command string; that is, 19127664Sbms * the characters which the user must type. 20127664Sbms * It is terminated by a null <0> byte. 21127664Sbms * The byte after the null byte is the action code associated 22127664Sbms * with the command string. 23127664Sbms * If an action byte is OR-ed with A_EXTRA, this indicates 24127664Sbms * that the option byte is followed by an extra string. 25127664Sbms * 26127664Sbms * There may be many command tables. 27127664Sbms * The first (default) table is built-in. 28127664Sbms * Other tables are read in from "lesskey" files. 29127664Sbms * All the tables are linked together and are searched in order. 30127664Sbms */ 31127664Sbms 32127664Sbms#include "less.h" 33127664Sbms#include "cmd.h" 34127664Sbms#include "lesskey.h" 35127664Sbms 36127664Sbmsextern int erase_char, erase2_char, kill_char; 37146768Ssamextern int secure; 38127664Sbms 39127664Sbms#define SK(k) \ 40127664Sbms SK_SPECIAL_KEY, (k), 6, 1, 1, 1 41127664Sbms/* 42127664Sbms * Command table is ordered roughly according to expected 43127664Sbms * frequency of use, so the common commands are near the beginning. 44127664Sbms */ 45127664Sbms 46127664Sbmsstatic unsigned char cmdtable[] = 47127664Sbms{ 48127664Sbms '\r',0, A_F_LINE, 49127664Sbms '\n',0, A_F_LINE, 50127664Sbms 'e',0, A_F_LINE, 51127664Sbms 'j',0, A_F_LINE, 52127664Sbms SK(SK_DOWN_ARROW),0, A_F_LINE, 53127664Sbms CONTROL('E'),0, A_F_LINE, 54127664Sbms CONTROL('N'),0, A_F_LINE, 55127664Sbms 'k',0, A_B_LINE, 56127664Sbms 'y',0, A_B_LINE, 57127664Sbms CONTROL('Y'),0, A_B_LINE, 58127664Sbms SK(SK_CONTROL_K),0, A_B_LINE, 59127664Sbms CONTROL('P'),0, A_B_LINE, 60127664Sbms SK(SK_UP_ARROW),0, A_B_LINE, 61127664Sbms 'J',0, A_FF_LINE, 62127664Sbms 'K',0, A_BF_LINE, 63127664Sbms 'Y',0, A_BF_LINE, 64127664Sbms 'd',0, A_F_SCROLL, 65127664Sbms CONTROL('D'),0, A_F_SCROLL, 66127664Sbms 'u',0, A_B_SCROLL, 67127664Sbms CONTROL('U'),0, A_B_SCROLL, 68127664Sbms ' ',0, A_F_SCREEN, 69127664Sbms 'f',0, A_F_SCREEN, 70127664Sbms CONTROL('F'),0, A_F_SCREEN, 71127664Sbms CONTROL('V'),0, A_F_SCREEN, 72127664Sbms SK(SK_PAGE_DOWN),0, A_F_SCREEN, 73127664Sbms 'b',0, A_B_SCREEN, 74127664Sbms CONTROL('B'),0, A_B_SCREEN, 75127664Sbms ESC,'v',0, A_B_SCREEN, 76127664Sbms SK(SK_PAGE_UP),0, A_B_SCREEN, 77127664Sbms 'z',0, A_F_WINDOW, 78127664Sbms 'w',0, A_B_WINDOW, 79127664Sbms ESC,' ',0, A_FF_SCREEN, 80127664Sbms 'F',0, A_F_FOREVER, 81127664Sbms ESC,'F',0, A_F_UNTIL_HILITE, 82127664Sbms 'R',0, A_FREPAINT, 83127664Sbms 'r',0, A_REPAINT, 84127664Sbms CONTROL('R'),0, A_REPAINT, 85127664Sbms CONTROL('L'),0, A_REPAINT, 86127664Sbms ESC,'u',0, A_UNDO_SEARCH, 87127664Sbms 'g',0, A_GOLINE, 88127664Sbms SK(SK_HOME),0, A_GOLINE, 89127664Sbms '<',0, A_GOLINE, 90127664Sbms ESC,'<',0, A_GOLINE, 91127664Sbms 'p',0, A_PERCENT, 92146768Ssam '%',0, A_PERCENT, 93146768Ssam ESC,'[',0, A_LSHIFT, 94146768Ssam ESC,']',0, A_RSHIFT, 95127664Sbms ESC,'(',0, A_LSHIFT, 96127664Sbms ESC,')',0, A_RSHIFT, 97127664Sbms SK(SK_RIGHT_ARROW),0, A_RSHIFT, 98127664Sbms SK(SK_LEFT_ARROW),0, A_LSHIFT, 99127664Sbms '{',0, A_F_BRACKET|A_EXTRA, '{','}',0, 100127664Sbms '}',0, A_B_BRACKET|A_EXTRA, '{','}',0, 101127664Sbms '(',0, A_F_BRACKET|A_EXTRA, '(',')',0, 102127664Sbms ')',0, A_B_BRACKET|A_EXTRA, '(',')',0, 103127664Sbms '[',0, A_F_BRACKET|A_EXTRA, '[',']',0, 104127664Sbms ']',0, A_B_BRACKET|A_EXTRA, '[',']',0, 105127664Sbms ESC,CONTROL('F'),0, A_F_BRACKET, 106127664Sbms ESC,CONTROL('B'),0, A_B_BRACKET, 107127664Sbms 'G',0, A_GOEND, 108127664Sbms ESC,'>',0, A_GOEND, 109127664Sbms '>',0, A_GOEND, 110127664Sbms SK(SK_END),0, A_GOEND, 111127664Sbms 'P',0, A_GOPOS, 112127664Sbms 113127664Sbms '0',0, A_DIGIT, 114127664Sbms '1',0, A_DIGIT, 115127664Sbms '2',0, A_DIGIT, 116127664Sbms '3',0, A_DIGIT, 117127664Sbms '4',0, A_DIGIT, 118127664Sbms '5',0, A_DIGIT, 119127664Sbms '6',0, A_DIGIT, 120127664Sbms '7',0, A_DIGIT, 121127664Sbms '8',0, A_DIGIT, 122127664Sbms '9',0, A_DIGIT, 123127664Sbms '.',0, A_DIGIT, 124127664Sbms 125127664Sbms '=',0, A_STAT, 126127664Sbms CONTROL('G'),0, A_STAT, 127127664Sbms ':','f',0, A_STAT, 128127664Sbms '/',0, A_F_SEARCH, 129127664Sbms '?',0, A_B_SEARCH, 130127664Sbms ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0, 131127664Sbms ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0, 132127664Sbms 'n',0, A_AGAIN_SEARCH, 133127664Sbms ESC,'n',0, A_T_AGAIN_SEARCH, 134127664Sbms 'N',0, A_REVERSE_SEARCH, 135127664Sbms ESC,'N',0, A_T_REVERSE_SEARCH, 136127664Sbms '&',0, A_FILTER, 137127664Sbms 'm',0, A_SETMARK, 138127664Sbms '\'',0, A_GOMARK, 139127664Sbms CONTROL('X'),CONTROL('X'),0, A_GOMARK, 140127664Sbms 'E',0, A_EXAMINE, 141127664Sbms ':','e',0, A_EXAMINE, 142127664Sbms CONTROL('X'),CONTROL('V'),0, A_EXAMINE, 143127664Sbms ':','n',0, A_NEXT_FILE, 144127664Sbms ':','p',0, A_PREV_FILE, 145127664Sbms 't',0, A_NEXT_TAG, 146127664Sbms 'T',0, A_PREV_TAG, 147127664Sbms ':','x',0, A_INDEX_FILE, 148127664Sbms ':','d',0, A_REMOVE_FILE, 149127664Sbms '-',0, A_OPT_TOGGLE, 150127664Sbms ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0, 151127664Sbms 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0, 152127664Sbms '_',0, A_DISP_OPTION, 153127664Sbms '|',0, A_PIPE, 154127664Sbms 'v',0, A_VISUAL, 155127664Sbms '!',0, A_SHELL, 156127664Sbms '+',0, A_FIRSTCMD, 157127664Sbms 158127664Sbms 'H',0, A_HELP, 159127664Sbms 'h',0, A_HELP, 160127664Sbms SK(SK_F1),0, A_HELP, 161127664Sbms 'V',0, A_VERSION, 162127664Sbms 'q',0, A_QUIT, 163127664Sbms 'Q',0, A_QUIT, 164127664Sbms ':','q',0, A_QUIT, 165127664Sbms ':','Q',0, A_QUIT, 166127664Sbms 'Z','Z',0, A_QUIT 167127664Sbms}; 168127664Sbms 169127664Sbmsstatic unsigned char edittable[] = 170127664Sbms{ 171127664Sbms '\t',0, EC_F_COMPLETE, /* TAB */ 172127664Sbms '\17',0, EC_B_COMPLETE, /* BACKTAB */ 173127664Sbms SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */ 174127664Sbms ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */ 175127664Sbms CONTROL('L'),0, EC_EXPAND, /* CTRL-L */ 176127664Sbms CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */ 177127664Sbms CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */ 178127664Sbms ESC,'l',0, EC_RIGHT, /* ESC l */ 179127664Sbms SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */ 180127664Sbms ESC,'h',0, EC_LEFT, /* ESC h */ 181146768Ssam SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */ 182146768Ssam ESC,'b',0, EC_W_LEFT, /* ESC b */ 183146768Ssam ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */ 184146768Ssam SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */ 185146768Ssam ESC,'w',0, EC_W_RIGHT, /* ESC w */ 186146768Ssam ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */ 187146768Ssam SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */ 188146768Ssam ESC,'i',0, EC_INSERT, /* ESC i */ 189146768Ssam SK(SK_INSERT),0, EC_INSERT, /* INSERT */ 190146768Ssam ESC,'x',0, EC_DELETE, /* ESC x */ 191146768Ssam SK(SK_DELETE),0, EC_DELETE, /* DELETE */ 192146768Ssam ESC,'X',0, EC_W_DELETE, /* ESC X */ 193146768Ssam ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */ 194146768Ssam SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */ 195146768Ssam SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */ 196146768Ssam ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */ 197146768Ssam ESC,'0',0, EC_HOME, /* ESC 0 */ 198146768Ssam SK(SK_HOME),0, EC_HOME, /* HOME */ 199146768Ssam ESC,'$',0, EC_END, /* ESC $ */ 200146768Ssam SK(SK_END),0, EC_END, /* END */ 201146768Ssam ESC,'k',0, EC_UP, /* ESC k */ 202146768Ssam SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */ 203146768Ssam ESC,'j',0, EC_DOWN, /* ESC j */ 204146768Ssam SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */ 205146768Ssam CONTROL('G'),0, EC_ABORT, /* CTRL-G */ 206146768Ssam}; 207146768Ssam 208146768Ssam/* 209146768Ssam * Structure to support a list of command tables. 210146768Ssam */ 211127664Sbmsstruct tablelist 212127664Sbms{ 213127664Sbms struct tablelist *t_next; 214127664Sbms char *t_start; 215127664Sbms char *t_end; 216127664Sbms}; 217127664Sbms 218127664Sbms/* 219127664Sbms * List of command tables and list of line-edit tables. 220127664Sbms */ 221127664Sbmsstatic struct tablelist *list_fcmd_tables = NULL; 222127664Sbmsstatic struct tablelist *list_ecmd_tables = NULL; 223127664Sbmsstatic struct tablelist *list_var_tables = NULL; 224127664Sbmsstatic struct tablelist *list_sysvar_tables = NULL; 225127664Sbms 226127664Sbms 227127664Sbms/* 228127664Sbms * Expand special key abbreviations in a command table. 229127664Sbms */ 230127664Sbms static void 231127664Sbmsexpand_special_keys(table, len) 232127664Sbms char *table; 233127664Sbms int len; 234127664Sbms{ 235127664Sbms register char *fm; 236127664Sbms register char *to; 237127664Sbms register int a; 238127664Sbms char *repl; 239127664Sbms int klen; 240127664Sbms 241127664Sbms for (fm = table; fm < table + len; ) 242127664Sbms { 243127664Sbms /* 244127664Sbms * Rewrite each command in the table with any 245127664Sbms * special key abbreviations expanded. 246127664Sbms */ 247127664Sbms for (to = fm; *fm != '\0'; ) 248127664Sbms { 249127664Sbms if (*fm != SK_SPECIAL_KEY) 250127664Sbms { 251127664Sbms *to++ = *fm++; 252127664Sbms continue; 253127664Sbms } 254127664Sbms /* 255127664Sbms * After SK_SPECIAL_KEY, next byte is the type 256127664Sbms * of special key (one of the SK_* contants), 257127664Sbms * and the byte after that is the number of bytes, 258127664Sbms * N, reserved by the abbreviation (including the 259127664Sbms * SK_SPECIAL_KEY and key type bytes). 260127664Sbms * Replace all N bytes with the actual bytes 261127664Sbms * output by the special key on this terminal. 262127664Sbms */ 263127664Sbms repl = special_key_str(fm[1]); 264127664Sbms klen = fm[2] & 0377; 265127664Sbms fm += klen; 266127664Sbms if (repl == NULL || (int) strlen(repl) > klen) 267127664Sbms repl = "\377"; 268127664Sbms while (*repl != '\0') 269127664Sbms *to++ = *repl++; 270127664Sbms } 271127664Sbms *to++ = '\0'; 272127664Sbms /* 273127664Sbms * Fill any unused bytes between end of command and 274127664Sbms * the action byte with A_SKIP. 275127664Sbms */ 276127664Sbms while (to <= fm) 277127664Sbms *to++ = A_SKIP; 278127664Sbms fm++; 279127664Sbms a = *fm++ & 0377; 280127664Sbms if (a & A_EXTRA) 281127664Sbms { 282127664Sbms while (*fm++ != '\0') 283127664Sbms continue; 284127664Sbms } 285127664Sbms } 286127664Sbms} 287127664Sbms 288127664Sbms/* 289127664Sbms * Initialize the command lists. 290127664Sbms */ 291127664Sbms public void 292127664Sbmsinit_cmds() 293127664Sbms{ 294127664Sbms /* 295127664Sbms * Add the default command tables. 296127664Sbms */ 297127664Sbms add_fcmd_table((char*)cmdtable, sizeof(cmdtable)); 298127664Sbms add_ecmd_table((char*)edittable, sizeof(edittable)); 299127664Sbms#if USERFILE 300127664Sbms /* 301127664Sbms * For backwards compatibility, 302127664Sbms * try to add tables in the OLD system lesskey file. 303127664Sbms */ 304127664Sbms#ifdef BINDIR 305127664Sbms add_hometable(NULL, BINDIR "/.sysless", 1); 306127664Sbms#endif 307127664Sbms /* 308127664Sbms * Try to add the tables in the system lesskey file. 309127664Sbms */ 310127664Sbms add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1); 311127664Sbms /* 312127664Sbms * Try to add the tables in the standard lesskey file "$HOME/.less". 313127664Sbms */ 314127664Sbms add_hometable("LESSKEY", LESSKEYFILE, 0); 315127664Sbms#endif 316127664Sbms} 317127664Sbms 318127664Sbms/* 319127664Sbms * Add a command table. 320146768Ssam */ 321127664Sbms static int 322146768Ssamadd_cmd_table(tlist, buf, len) 323146768Ssam struct tablelist **tlist; 324146768Ssam char *buf; 325146768Ssam int len; 326146768Ssam{ 327146768Ssam register struct tablelist *t; 328146768Ssam 329146768Ssam if (len == 0) 330146768Ssam return (0); 331146768Ssam /* 332146768Ssam * Allocate a tablelist structure, initialize it, 333146768Ssam * and link it into the list of tables. 334146768Ssam */ 335146768Ssam if ((t = (struct tablelist *) 336146768Ssam calloc(1, sizeof(struct tablelist))) == NULL) 337146768Ssam { 338146768Ssam return (-1); 339146768Ssam } 340146768Ssam expand_special_keys(buf, len); 341146768Ssam t->t_start = buf; 342146768Ssam t->t_end = buf + len; 343146768Ssam t->t_next = *tlist; 344146768Ssam *tlist = t; 345146768Ssam return (0); 346146768Ssam} 347146768Ssam 348146768Ssam/* 349127664Sbms * Add a command table. 350127664Sbms */ 351127664Sbms public void 352127664Sbmsadd_fcmd_table(buf, len) 353127664Sbms char *buf; 354127664Sbms int len; 355127664Sbms{ 356127664Sbms if (add_cmd_table(&list_fcmd_tables, buf, len) < 0) 357127664Sbms error("Warning: some commands disabled", NULL_PARG); 358127664Sbms} 359127664Sbms 360127664Sbms/* 361127664Sbms * Add an editing command table. 362127664Sbms */ 363127664Sbms public void 364127664Sbmsadd_ecmd_table(buf, len) 365127664Sbms char *buf; 366127664Sbms int len; 367127664Sbms{ 368127664Sbms if (add_cmd_table(&list_ecmd_tables, buf, len) < 0) 369127664Sbms error("Warning: some edit commands disabled", NULL_PARG); 370127664Sbms} 371127664Sbms 372127664Sbms/* 373127664Sbms * Add an environment variable table. 374127664Sbms */ 375127664Sbms static void 376127664Sbmsadd_var_table(tlist, buf, len) 377127664Sbms struct tablelist **tlist; 378127664Sbms char *buf; 379127664Sbms int len; 380127664Sbms{ 381127664Sbms if (add_cmd_table(tlist, buf, len) < 0) 382127664Sbms error("Warning: environment variables from lesskey file unavailable", NULL_PARG); 383127664Sbms} 384127664Sbms 385127664Sbms/* 386127664Sbms * Search a single command table for the command string in cmd. 387 */ 388 static int 389cmd_search(cmd, table, endtable, sp) 390 char *cmd; 391 char *table; 392 char *endtable; 393 char **sp; 394{ 395 register char *p; 396 register char *q; 397 register int a; 398 399 *sp = NULL; 400 for (p = table, q = cmd; p < endtable; p++, q++) 401 { 402 if (*p == *q) 403 { 404 /* 405 * Current characters match. 406 * If we're at the end of the string, we've found it. 407 * Return the action code, which is the character 408 * after the null at the end of the string 409 * in the command table. 410 */ 411 if (*p == '\0') 412 { 413 a = *++p & 0377; 414 while (a == A_SKIP) 415 a = *++p & 0377; 416 if (a == A_END_LIST) 417 { 418 /* 419 * We get here only if the original 420 * cmd string passed in was empty (""). 421 * I don't think that can happen, 422 * but just in case ... 423 */ 424 return (A_UINVALID); 425 } 426 /* 427 * Check for an "extra" string. 428 */ 429 if (a & A_EXTRA) 430 { 431 *sp = ++p; 432 a &= ~A_EXTRA; 433 } 434 return (a); 435 } 436 } else if (*q == '\0') 437 { 438 /* 439 * Hit the end of the user's command, 440 * but not the end of the string in the command table. 441 * The user's command is incomplete. 442 */ 443 return (A_PREFIX); 444 } else 445 { 446 /* 447 * Not a match. 448 * Skip ahead to the next command in the 449 * command table, and reset the pointer 450 * to the beginning of the user's command. 451 */ 452 if (*p == '\0' && p[1] == A_END_LIST) 453 { 454 /* 455 * A_END_LIST is a special marker that tells 456 * us to abort the cmd search. 457 */ 458 return (A_UINVALID); 459 } 460 while (*p++ != '\0') 461 continue; 462 while (*p == A_SKIP) 463 p++; 464 if (*p & A_EXTRA) 465 while (*++p != '\0') 466 continue; 467 q = cmd-1; 468 } 469 } 470 /* 471 * No match found in the entire command table. 472 */ 473 return (A_INVALID); 474} 475 476/* 477 * Decode a command character and return the associated action. 478 * The "extra" string, if any, is returned in sp. 479 */ 480 static int 481cmd_decode(tlist, cmd, sp) 482 struct tablelist *tlist; 483 char *cmd; 484 char **sp; 485{ 486 register struct tablelist *t; 487 register int action = A_INVALID; 488 489 /* 490 * Search thru all the command tables. 491 * Stop when we find an action which is not A_INVALID. 492 */ 493 for (t = tlist; t != NULL; t = t->t_next) 494 { 495 action = cmd_search(cmd, t->t_start, t->t_end, sp); 496 if (action != A_INVALID) 497 break; 498 } 499 if (action == A_UINVALID) 500 action = A_INVALID; 501 return (action); 502} 503 504/* 505 * Decode a command from the cmdtables list. 506 */ 507 public int 508fcmd_decode(cmd, sp) 509 char *cmd; 510 char **sp; 511{ 512 return (cmd_decode(list_fcmd_tables, cmd, sp)); 513} 514 515/* 516 * Decode a command from the edittables list. 517 */ 518 public int 519ecmd_decode(cmd, sp) 520 char *cmd; 521 char **sp; 522{ 523 return (cmd_decode(list_ecmd_tables, cmd, sp)); 524} 525 526/* 527 * Get the value of an environment variable. 528 * Looks first in the lesskey file, then in the real environment. 529 */ 530 public char * 531lgetenv(var) 532 char *var; 533{ 534 int a; 535 char *s; 536 537 a = cmd_decode(list_var_tables, var, &s); 538 if (a == EV_OK) 539 return (s); 540 s = getenv(var); 541 if (s != NULL && *s != '\0') 542 return (s); 543 a = cmd_decode(list_sysvar_tables, var, &s); 544 if (a == EV_OK) 545 return (s); 546 return (NULL); 547} 548 549#if USERFILE 550/* 551 * Get an "integer" from a lesskey file. 552 * Integers are stored in a funny format: 553 * two bytes, low order first, in radix KRADIX. 554 */ 555 static int 556gint(sp) 557 char **sp; 558{ 559 int n; 560 561 n = *(*sp)++; 562 n += *(*sp)++ * KRADIX; 563 return (n); 564} 565 566/* 567 * Process an old (pre-v241) lesskey file. 568 */ 569 static int 570old_lesskey(buf, len) 571 char *buf; 572 int len; 573{ 574 /* 575 * Old-style lesskey file. 576 * The file must end with either 577 * ...,cmd,0,action 578 * or ...,cmd,0,action|A_EXTRA,string,0 579 * So the last byte or the second to last byte must be zero. 580 */ 581 if (buf[len-1] != '\0' && buf[len-2] != '\0') 582 return (-1); 583 add_fcmd_table(buf, len); 584 return (0); 585} 586 587/* 588 * Process a new (post-v241) lesskey file. 589 */ 590 static int 591new_lesskey(buf, len, sysvar) 592 char *buf; 593 int len; 594 int sysvar; 595{ 596 char *p; 597 register int c; 598 register int n; 599 600 /* 601 * New-style lesskey file. 602 * Extract the pieces. 603 */ 604 if (buf[len-3] != C0_END_LESSKEY_MAGIC || 605 buf[len-2] != C1_END_LESSKEY_MAGIC || 606 buf[len-1] != C2_END_LESSKEY_MAGIC) 607 return (-1); 608 p = buf + 4; 609 for (;;) 610 { 611 c = *p++; 612 switch (c) 613 { 614 case CMD_SECTION: 615 n = gint(&p); 616 add_fcmd_table(p, n); 617 p += n; 618 break; 619 case EDIT_SECTION: 620 n = gint(&p); 621 add_ecmd_table(p, n); 622 p += n; 623 break; 624 case VAR_SECTION: 625 n = gint(&p); 626 add_var_table((sysvar) ? 627 &list_sysvar_tables : &list_var_tables, p, n); 628 p += n; 629 break; 630 case END_SECTION: 631 return (0); 632 default: 633 /* 634 * Unrecognized section type. 635 */ 636 return (-1); 637 } 638 } 639} 640 641/* 642 * Set up a user command table, based on a "lesskey" file. 643 */ 644 public int 645lesskey(filename, sysvar) 646 char *filename; 647 int sysvar; 648{ 649 register char *buf; 650 register POSITION len; 651 register long n; 652 register int f; 653 654 if (secure) 655 return (1); 656 /* 657 * Try to open the lesskey file. 658 */ 659 filename = shell_unquote(filename); 660 f = open(filename, OPEN_READ); 661 free(filename); 662 if (f < 0) 663 return (1); 664 665 /* 666 * Read the file into a buffer. 667 * We first figure out the size of the file and allocate space for it. 668 * {{ Minimal error checking is done here. 669 * A garbage .less file will produce strange results. 670 * To avoid a large amount of error checking code here, we 671 * rely on the lesskey program to generate a good .less file. }} 672 */ 673 len = filesize(f); 674 if (len == NULL_POSITION || len < 3) 675 { 676 /* 677 * Bad file (valid file must have at least 3 chars). 678 */ 679 close(f); 680 return (-1); 681 } 682 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL) 683 { 684 close(f); 685 return (-1); 686 } 687 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK) 688 { 689 free(buf); 690 close(f); 691 return (-1); 692 } 693 n = read(f, buf, (unsigned int) len); 694 close(f); 695 if (n != len) 696 { 697 free(buf); 698 return (-1); 699 } 700 701 /* 702 * Figure out if this is an old-style (before version 241) 703 * or new-style lesskey file format. 704 */ 705 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC || 706 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC) 707 return (old_lesskey(buf, (int)len)); 708 return (new_lesskey(buf, (int)len, sysvar)); 709} 710 711/* 712 * Add the standard lesskey file "$HOME/.less" 713 */ 714 public void 715add_hometable(envname, def_filename, sysvar) 716 char *envname; 717 char *def_filename; 718 int sysvar; 719{ 720 char *filename; 721 PARG parg; 722 723 if (envname != NULL && (filename = lgetenv(envname)) != NULL) 724 filename = save(filename); 725 else if (sysvar) 726 filename = save(def_filename); 727 else 728 filename = homefile(def_filename); 729 if (filename == NULL) 730 return; 731 if (lesskey(filename, sysvar) < 0) 732 { 733 parg.p_string = filename; 734 error("Cannot use lesskey file \"%s\"", &parg); 735 } 736 free(filename); 737} 738#endif 739 740/* 741 * See if a char is a special line-editing command. 742 */ 743 public int 744editchar(c, flags) 745 int c; 746 int flags; 747{ 748 int action; 749 int nch; 750 char *s; 751 char usercmd[MAX_CMDLEN+1]; 752 753 /* 754 * An editing character could actually be a sequence of characters; 755 * for example, an escape sequence sent by pressing the uparrow key. 756 * To match the editing string, we use the command decoder 757 * but give it the edit-commands command table 758 * This table is constructed to match the user's keyboard. 759 */ 760 if (c == erase_char || c == erase2_char) 761 return (EC_BACKSPACE); 762 if (c == kill_char) 763 return (EC_LINEKILL); 764 765 /* 766 * Collect characters in a buffer. 767 * Start with the one we have, and get more if we need them. 768 */ 769 nch = 0; 770 do { 771 if (nch > 0) 772 c = getcc(); 773 usercmd[nch] = c; 774 usercmd[nch+1] = '\0'; 775 nch++; 776 action = ecmd_decode(usercmd, &s); 777 } while (action == A_PREFIX); 778 779 if (flags & EC_NORIGHTLEFT) 780 { 781 switch (action) 782 { 783 case EC_RIGHT: 784 case EC_LEFT: 785 action = A_INVALID; 786 break; 787 } 788 } 789#if CMD_HISTORY 790 if (flags & EC_NOHISTORY) 791 { 792 /* 793 * The caller says there is no history list. 794 * Reject any history-manipulation action. 795 */ 796 switch (action) 797 { 798 case EC_UP: 799 case EC_DOWN: 800 action = A_INVALID; 801 break; 802 } 803 } 804#endif 805#if TAB_COMPLETE_FILENAME 806 if (flags & EC_NOCOMPLETE) 807 { 808 /* 809 * The caller says we don't want any filename completion cmds. 810 * Reject them. 811 */ 812 switch (action) 813 { 814 case EC_F_COMPLETE: 815 case EC_B_COMPLETE: 816 case EC_EXPAND: 817 action = A_INVALID; 818 break; 819 } 820 } 821#endif 822 if ((flags & EC_PEEK) || action == A_INVALID) 823 { 824 /* 825 * We're just peeking, or we didn't understand the command. 826 * Unget all the characters we read in the loop above. 827 * This does NOT include the original character that was 828 * passed in as a parameter. 829 */ 830 while (nch > 1) 831 { 832 ungetcc(usercmd[--nch]); 833 } 834 } else 835 { 836 if (s != NULL) 837 ungetsc(s); 838 } 839 return action; 840} 841 842