1 /* 2 * Copyright (C) 1984-2007 Mark Nudelman 3 * 4 * You may distribute under the terms of either the GNU General Public 5 * License or the Less License, as specified in the README file. 6 * 7 * For more information about less, or for information on how to 8 * contact the author, see the README file. 9 */ 10 11 12 /* 13 * Process command line options. 14 * 15 * Each option is a single letter which controls a program variable. 16 * The options have defaults which may be changed via 17 * the command line option, toggled via the "-" command, 18 * or queried via the "_" command. 19 */ 20 21 #include "less.h" 22 #include "option.h" 23 24 static struct loption *pendopt; 25 public int plusoption = FALSE; 26 27 static char *propt(); 28 static char *optstring(); 29 static int flip_triple(); 30 31 extern int screen_trashed; 32 extern int less_is_more; 33 extern int quit_at_eof; 34 extern char *every_first_cmd; 35 36 /* 37 * Scan an argument (either from the command line or from the 38 * LESS environment variable) and process it. 39 */ 40 public void 41 scan_option(s) 42 char *s; 43 { 44 register struct loption *o; 45 register int optc; 46 char *optname; 47 char *printopt; 48 char *str; 49 int set_default; 50 int lc; 51 int err; 52 PARG parg; 53 54 if (s == NULL) 55 return; 56 57 /* 58 * If we have a pending option which requires an argument, 59 * handle it now. 60 * This happens if the previous option was, for example, "-P" 61 * without a following string. In that case, the current 62 * option is simply the argument for the previous option. 63 */ 64 if (pendopt != NULL) 65 { 66 switch (pendopt->otype & OTYPE) 67 { 68 case STRING: 69 (*pendopt->ofunc)(INIT, s); 70 break; 71 case NUMBER: 72 printopt = propt(pendopt->oletter); 73 *(pendopt->ovar) = getnum(&s, printopt, (int*)NULL); 74 break; 75 } 76 pendopt = NULL; 77 return; 78 } 79 80 set_default = FALSE; 81 optname = NULL; 82 83 while (*s != '\0') 84 { 85 /* 86 * Check some special cases first. 87 */ 88 switch (optc = *s++) 89 { 90 case ' ': 91 case '\t': 92 case END_OPTION_STRING: 93 continue; 94 case '-': 95 /* 96 * "--" indicates an option name instead of a letter. 97 */ 98 if (*s == '-') 99 { 100 optname = ++s; 101 break; 102 } 103 /* 104 * "-+" means set these options back to their defaults. 105 * (They may have been set otherwise by previous 106 * options.) 107 */ 108 set_default = (*s == '+'); 109 if (set_default) 110 s++; 111 continue; 112 case '+': 113 /* 114 * An option prefixed by a "+" is ungotten, so 115 * that it is interpreted as less commands 116 * processed at the start of the first input file. 117 * "++" means process the commands at the start of 118 * EVERY input file. 119 */ 120 plusoption = TRUE; 121 s = optstring(s, &str, propt('+'), NULL); 122 if (*str == '+') 123 every_first_cmd = save(++str); 124 else 125 ungetsc(str); 126 continue; 127 case '0': case '1': case '2': case '3': case '4': 128 case '5': case '6': case '7': case '8': case '9': 129 /* 130 * Special "more" compatibility form "-<number>" 131 * instead of -z<number> to set the scrolling 132 * window size. 133 */ 134 s--; 135 optc = 'z'; 136 break; 137 case 'n': 138 if (less_is_more) 139 optc = 'z'; 140 break; 141 } 142 143 /* 144 * Not a special case. 145 * Look up the option letter in the option table. 146 */ 147 err = 0; 148 if (optname == NULL) 149 { 150 printopt = propt(optc); 151 lc = ASCII_IS_LOWER(optc); 152 o = findopt(optc); 153 } else 154 { 155 printopt = optname; 156 lc = ASCII_IS_LOWER(optname[0]); 157 o = findopt_name(&optname, NULL, &err); 158 s = optname; 159 optname = NULL; 160 if (*s == '\0' || *s == ' ') 161 { 162 /* 163 * The option name matches exactly. 164 */ 165 ; 166 } else if (*s == '=') 167 { 168 /* 169 * The option name is followed by "=value". 170 */ 171 if (o != NULL && 172 (o->otype & OTYPE) != STRING && 173 (o->otype & OTYPE) != NUMBER) 174 { 175 parg.p_string = printopt; 176 error("The %s option should not be followed by =", 177 &parg); 178 quit(QUIT_ERROR); 179 } 180 s++; 181 } else 182 { 183 /* 184 * The specified name is longer than the 185 * real option name. 186 */ 187 o = NULL; 188 } 189 } 190 if (o == NULL) 191 { 192 parg.p_string = printopt; 193 if (err == OPT_AMBIG) 194 error("%s is an ambiguous abbreviation (\"less --help\" for help)", 195 &parg); 196 else 197 error("There is no %s option (\"less --help\" for help)", 198 &parg); 199 quit(QUIT_ERROR); 200 } 201 202 str = NULL; 203 switch (o->otype & OTYPE) 204 { 205 case BOOL: 206 if (set_default) 207 *(o->ovar) = o->odefault; 208 else 209 *(o->ovar) = ! o->odefault; 210 break; 211 case TRIPLE: 212 if (set_default) 213 *(o->ovar) = o->odefault; 214 else 215 *(o->ovar) = flip_triple(o->odefault, lc); 216 break; 217 case STRING: 218 if (*s == '\0') 219 { 220 /* 221 * Set pendopt and return. 222 * We will get the string next time 223 * scan_option is called. 224 */ 225 pendopt = o; 226 return; 227 } 228 /* 229 * Don't do anything here. 230 * All processing of STRING options is done by 231 * the handling function. 232 */ 233 while (*s == ' ') 234 s++; 235 s = optstring(s, &str, printopt, o->odesc[1]); 236 break; 237 case NUMBER: 238 if (*s == '\0') 239 { 240 pendopt = o; 241 return; 242 } 243 *(o->ovar) = getnum(&s, printopt, (int*)NULL); 244 break; 245 } 246 /* 247 * If the option has a handling function, call it. 248 */ 249 if (o->ofunc != NULL) 250 (*o->ofunc)(INIT, str); 251 } 252 } 253 254 /* 255 * Toggle command line flags from within the program. 256 * Used by the "-" and "_" commands. 257 * how_toggle may be: 258 * OPT_NO_TOGGLE just report the current setting, without changing it. 259 * OPT_TOGGLE invert the current setting 260 * OPT_UNSET set to the default value 261 * OPT_SET set to the inverse of the default value 262 */ 263 public void 264 toggle_option(c, s, how_toggle) 265 int c; 266 char *s; 267 int how_toggle; 268 { 269 register struct loption *o; 270 register int num; 271 int no_prompt; 272 int err; 273 PARG parg; 274 275 no_prompt = (how_toggle & OPT_NO_PROMPT); 276 how_toggle &= ~OPT_NO_PROMPT; 277 278 /* 279 * Look up the option letter in the option table. 280 */ 281 o = findopt(c); 282 if (o == NULL) 283 { 284 parg.p_string = propt(c); 285 error("There is no %s option", &parg); 286 return; 287 } 288 289 if (how_toggle == OPT_TOGGLE && (o->otype & NO_TOGGLE)) 290 { 291 parg.p_string = propt(c); 292 error("Cannot change the %s option", &parg); 293 return; 294 } 295 296 if (how_toggle == OPT_NO_TOGGLE && (o->otype & NO_QUERY)) 297 { 298 parg.p_string = propt(c); 299 error("Cannot query the %s option", &parg); 300 return; 301 } 302 303 /* 304 * Check for something which appears to be a do_toggle 305 * (because the "-" command was used), but really is not. 306 * This could be a string option with no string, or 307 * a number option with no number. 308 */ 309 switch (o->otype & OTYPE) 310 { 311 case STRING: 312 case NUMBER: 313 if (how_toggle == OPT_TOGGLE && *s == '\0') 314 how_toggle = OPT_NO_TOGGLE; 315 break; 316 } 317 318 #if HILITE_SEARCH 319 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT)) 320 repaint_hilite(0); 321 #endif 322 323 /* 324 * Now actually toggle (change) the variable. 325 */ 326 if (how_toggle != OPT_NO_TOGGLE) 327 { 328 switch (o->otype & OTYPE) 329 { 330 case BOOL: 331 /* 332 * Boolean. 333 */ 334 switch (how_toggle) 335 { 336 case OPT_TOGGLE: 337 *(o->ovar) = ! *(o->ovar); 338 break; 339 case OPT_UNSET: 340 *(o->ovar) = o->odefault; 341 break; 342 case OPT_SET: 343 *(o->ovar) = ! o->odefault; 344 break; 345 } 346 break; 347 case TRIPLE: 348 /* 349 * Triple: 350 * If user gave the lower case letter, then switch 351 * to 1 unless already 1, in which case make it 0. 352 * If user gave the upper case letter, then switch 353 * to 2 unless already 2, in which case make it 0. 354 */ 355 switch (how_toggle) 356 { 357 case OPT_TOGGLE: 358 *(o->ovar) = flip_triple(*(o->ovar), 359 ASCII_IS_LOWER(c)); 360 break; 361 case OPT_UNSET: 362 *(o->ovar) = o->odefault; 363 break; 364 case OPT_SET: 365 *(o->ovar) = flip_triple(o->odefault, 366 ASCII_IS_LOWER(c)); 367 break; 368 } 369 break; 370 case STRING: 371 /* 372 * String: don't do anything here. 373 * The handling function will do everything. 374 */ 375 switch (how_toggle) 376 { 377 case OPT_SET: 378 case OPT_UNSET: 379 error("Cannot use \"-+\" or \"--\" for a string option", 380 NULL_PARG); 381 return; 382 } 383 break; 384 case NUMBER: 385 /* 386 * Number: set the variable to the given number. 387 */ 388 switch (how_toggle) 389 { 390 case OPT_TOGGLE: 391 num = getnum(&s, NULL, &err); 392 if (!err) 393 *(o->ovar) = num; 394 break; 395 case OPT_UNSET: 396 *(o->ovar) = o->odefault; 397 break; 398 case OPT_SET: 399 error("Can't use \"-!\" for a numeric option", 400 NULL_PARG); 401 return; 402 } 403 break; 404 } 405 } 406 407 /* 408 * Call the handling function for any special action 409 * specific to this option. 410 */ 411 if (o->ofunc != NULL) 412 (*o->ofunc)((how_toggle==OPT_NO_TOGGLE) ? QUERY : TOGGLE, s); 413 414 #if HILITE_SEARCH 415 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT)) 416 chg_hilite(); 417 #endif 418 419 if (!no_prompt) 420 { 421 /* 422 * Print a message describing the new setting. 423 */ 424 switch (o->otype & OTYPE) 425 { 426 case BOOL: 427 case TRIPLE: 428 /* 429 * Print the odesc message. 430 */ 431 error(o->odesc[*(o->ovar)], NULL_PARG); 432 break; 433 case NUMBER: 434 /* 435 * The message is in odesc[1] and has a %d for 436 * the value of the variable. 437 */ 438 parg.p_int = *(o->ovar); 439 error(o->odesc[1], &parg); 440 break; 441 case STRING: 442 /* 443 * Message was already printed by the handling function. 444 */ 445 break; 446 } 447 } 448 449 if (how_toggle != OPT_NO_TOGGLE && (o->otype & REPAINT)) 450 screen_trashed = TRUE; 451 } 452 453 /* 454 * "Toggle" a triple-valued option. 455 */ 456 static int 457 flip_triple(val, lc) 458 int val; 459 int lc; 460 { 461 if (lc) 462 return ((val == OPT_ON) ? OPT_OFF : OPT_ON); 463 else 464 return ((val == OPT_ONPLUS) ? OPT_OFF : OPT_ONPLUS); 465 } 466 467 /* 468 * Return a string suitable for printing as the "name" of an option. 469 * For example, if the option letter is 'x', just return "-x". 470 */ 471 static char * 472 propt(c) 473 int c; 474 { 475 static char buf[8]; 476 477 sprintf(buf, "-%s", prchar(c)); 478 return (buf); 479 } 480 481 /* 482 * Determine if an option is a single character option (BOOL or TRIPLE), 483 * or if it a multi-character option (NUMBER). 484 */ 485 public int 486 single_char_option(c) 487 int c; 488 { 489 register struct loption *o; 490 491 o = findopt(c); 492 if (o == NULL) 493 return (TRUE); 494 return ((o->otype & (BOOL|TRIPLE|NOVAR|NO_TOGGLE)) != 0); 495 } 496 497 /* 498 * Return the prompt to be used for a given option letter. 499 * Only string and number valued options have prompts. 500 */ 501 public char * 502 opt_prompt(c) 503 int c; 504 { 505 register struct loption *o; 506 507 o = findopt(c); 508 if (o == NULL || (o->otype & (STRING|NUMBER)) == 0) 509 return (NULL); 510 return (o->odesc[0]); 511 } 512 513 /* 514 * Return whether or not there is a string option pending; 515 * that is, if the previous option was a string-valued option letter 516 * (like -P) without a following string. 517 * In that case, the current option is taken to be the string for 518 * the previous option. 519 */ 520 public int 521 isoptpending() 522 { 523 return (pendopt != NULL); 524 } 525 526 /* 527 * Print error message about missing string. 528 */ 529 static void 530 nostring(printopt) 531 char *printopt; 532 { 533 PARG parg; 534 parg.p_string = printopt; 535 error("Value is required after %s", &parg); 536 } 537 538 /* 539 * Print error message if a STRING type option is not followed by a string. 540 */ 541 public void 542 nopendopt() 543 { 544 nostring(propt(pendopt->oletter)); 545 } 546 547 /* 548 * Scan to end of string or to an END_OPTION_STRING character. 549 * In the latter case, replace the char with a null char. 550 * Return a pointer to the remainder of the string, if any. 551 */ 552 static char * 553 optstring(s, p_str, printopt, validchars) 554 char *s; 555 char **p_str; 556 char *printopt; 557 char *validchars; 558 { 559 register char *p; 560 561 if (*s == '\0') 562 { 563 nostring(printopt); 564 quit(QUIT_ERROR); 565 } 566 *p_str = s; 567 for (p = s; *p != '\0'; p++) 568 { 569 if (*p == END_OPTION_STRING || 570 (validchars != NULL && strchr(validchars, *p) == NULL)) 571 { 572 switch (*p) 573 { 574 case END_OPTION_STRING: 575 case ' ': case '\t': case '-': 576 /* Replace the char with a null to terminate string. */ 577 *p++ = '\0'; 578 break; 579 default: 580 /* Cannot replace char; make a copy of the string. */ 581 *p_str = (char *) ecalloc(p-s+1, sizeof(char)); 582 strncpy(*p_str, s, p-s); 583 (*p_str)[p-s] = '\0'; 584 break; 585 } 586 break; 587 } 588 } 589 return (p); 590 } 591 592 /* 593 */ 594 static int 595 num_error(printopt, errp) 596 char *printopt; 597 int *errp; 598 { 599 PARG parg; 600 601 if (errp != NULL) 602 { 603 *errp = TRUE; 604 return (-1); 605 } 606 if (printopt != NULL) 607 { 608 parg.p_string = printopt; 609 error("Number is required after %s", &parg); 610 } 611 quit(QUIT_ERROR); 612 /* NOTREACHED */ 613 return (-1); 614 } 615 616 /* 617 * Translate a string into a number. 618 * Like atoi(), but takes a pointer to a char *, and updates 619 * the char * to point after the translated number. 620 */ 621 public int 622 getnum(sp, printopt, errp) 623 char **sp; 624 char *printopt; 625 int *errp; 626 { 627 register char *s; 628 register int n; 629 register int neg; 630 631 s = skipsp(*sp); 632 neg = FALSE; 633 if (*s == '-') 634 { 635 neg = TRUE; 636 s++; 637 } 638 if (*s < '0' || *s > '9') 639 return (num_error(printopt, errp)); 640 641 n = 0; 642 while (*s >= '0' && *s <= '9') 643 n = 10 * n + *s++ - '0'; 644 *sp = s; 645 if (errp != NULL) 646 *errp = FALSE; 647 if (neg) 648 n = -n; 649 return (n); 650 } 651 652 /* 653 * Translate a string into a fraction, represented by the part of a 654 * number which would follow a decimal point. 655 * The value of the fraction is returned as parts per NUM_FRAC_DENOM. 656 * That is, if "n" is returned, the fraction intended is n/NUM_FRAC_DENOM. 657 */ 658 public long 659 getfraction(sp, printopt, errp) 660 char **sp; 661 char *printopt; 662 int *errp; 663 { 664 register char *s; 665 long frac = 0; 666 int fraclen = 0; 667 668 s = skipsp(*sp); 669 if (*s < '0' || *s > '9') 670 return (num_error(printopt, errp)); 671 672 for ( ; *s >= '0' && *s <= '9'; s++) 673 { 674 frac = (frac * 10) + (*s - '0'); 675 fraclen++; 676 } 677 if (fraclen > NUM_LOG_FRAC_DENOM) 678 while (fraclen-- > NUM_LOG_FRAC_DENOM) 679 frac /= 10; 680 else 681 while (fraclen++ < NUM_LOG_FRAC_DENOM) 682 frac *= 10; 683 *sp = s; 684 if (errp != NULL) 685 *errp = FALSE; 686 return (frac); 687 } 688 689 690 /* 691 * Get the value of the -e flag. 692 */ 693 public int 694 get_quit_at_eof() 695 { 696 if (!less_is_more) 697 return quit_at_eof; 698 /* When less_is_more is set, the -e flag semantics are different. */ 699 return quit_at_eof ? OPT_ON : OPT_ONPLUS; 700 } 701