option.c revision 221715
155682Smarkm/* 272445Sassar * Copyright (C) 1984-2011 Mark Nudelman 355682Smarkm * 455682Smarkm * You may distribute under the terms of either the GNU General Public 555682Smarkm * License or the Less License, as specified in the README file. 655682Smarkm * 755682Smarkm * For more information about less, or for information on how to 855682Smarkm * contact the author, see the README file. 955682Smarkm */ 1055682Smarkm 1155682Smarkm 1255682Smarkm/* 1355682Smarkm * Process command line options. 1455682Smarkm * 1555682Smarkm * Each option is a single letter which controls a program variable. 1655682Smarkm * The options have defaults which may be changed via 1755682Smarkm * the command line option, toggled via the "-" command, 1855682Smarkm * or queried via the "_" command. 1955682Smarkm */ 2055682Smarkm 2155682Smarkm#include "less.h" 2255682Smarkm#include "option.h" 2355682Smarkm 2455682Smarkmstatic struct loption *pendopt; 2555682Smarkmpublic int plusoption = FALSE; 2655682Smarkm 2755682Smarkmstatic char *optstring(); 2855682Smarkmstatic int flip_triple(); 2955682Smarkm 3055682Smarkmextern int screen_trashed; 3155682Smarkmextern int less_is_more; 3255682Smarkmextern int quit_at_eof; 3355682Smarkmextern char *every_first_cmd; 34178825Sdfr 3555682Smarkm/* 36102644Snectar * Return a printable description of an option. 37102644Snectar */ 3855682Smarkm static char * 3955682Smarkmopt_desc(o) 40178825Sdfr struct loption *o; 4155682Smarkm{ 42178825Sdfr static char buf[OPTNAME_MAX + 10]; 4355682Smarkm if (o->oletter == OLETTER_NONE) 4455682Smarkm SNPRINTF1(buf, sizeof(buf), "--%s", o->onames->oname); 4555682Smarkm else 4655682Smarkm SNPRINTF2(buf, sizeof(buf), "-%c (--%s)", o->oletter, o->onames->oname); 47178825Sdfr return (buf); 4855682Smarkm} 49178825Sdfr 50178825Sdfr/* 5155682Smarkm * Return a string suitable for printing as the "name" of an option. 5255682Smarkm * For example, if the option letter is 'x', just return "-x". 5355682Smarkm */ 5472445Sassar public char * 5572445Sassarpropt(c) 5655682Smarkm int c; 5755682Smarkm{ 5855682Smarkm static char buf[8]; 5955682Smarkm 6055682Smarkm sprintf(buf, "-%s", prchar(c)); 6155682Smarkm return (buf); 6255682Smarkm} 6355682Smarkm 6455682Smarkm/* 6555682Smarkm * Scan an argument (either from the command line or from the 6655682Smarkm * LESS environment variable) and process it. 6755682Smarkm */ 6855682Smarkm public void 6955682Smarkmscan_option(s) 7055682Smarkm char *s; 7155682Smarkm{ 7255682Smarkm register struct loption *o; 7355682Smarkm register int optc; 7455682Smarkm char *optname; 7555682Smarkm char *printopt; 76178825Sdfr char *str; 7755682Smarkm int set_default; 7855682Smarkm int lc; 7955682Smarkm int err; 8055682Smarkm PARG parg; 8155682Smarkm 8255682Smarkm if (s == NULL) 8355682Smarkm return; 8455682Smarkm 8555682Smarkm /* 8655682Smarkm * If we have a pending option which requires an argument, 8755682Smarkm * handle it now. 8855682Smarkm * This happens if the previous option was, for example, "-P" 8955682Smarkm * without a following string. In that case, the current 9055682Smarkm * option is simply the argument for the previous option. 9172445Sassar */ 9255682Smarkm if (pendopt != NULL) 9355682Smarkm { 9455682Smarkm switch (pendopt->otype & OTYPE) 9555682Smarkm { 9655682Smarkm case STRING: 9755682Smarkm (*pendopt->ofunc)(INIT, s); 9855682Smarkm break; 9955682Smarkm case NUMBER: 10055682Smarkm printopt = opt_desc(pendopt); 10155682Smarkm *(pendopt->ovar) = getnum(&s, printopt, (int*)NULL); 10255682Smarkm break; 10372445Sassar } 10472445Sassar pendopt = NULL; 10572445Sassar return; 10672445Sassar } 10772445Sassar 10872445Sassar set_default = FALSE; 10955682Smarkm optname = NULL; 11055682Smarkm 111178825Sdfr while (*s != '\0') 112178825Sdfr { 113178825Sdfr /* 114178825Sdfr * Check some special cases first. 115178825Sdfr */ 116178825Sdfr switch (optc = *s++) 117178825Sdfr { 118178825Sdfr case ' ': 119178825Sdfr case '\t': 120178825Sdfr case END_OPTION_STRING: 121178825Sdfr continue; 122178825Sdfr case '-': 123178825Sdfr /* 124178825Sdfr * "--" indicates an option name instead of a letter. 12555682Smarkm */ 12655682Smarkm if (*s == '-') 12755682Smarkm { 12855682Smarkm optname = ++s; 12955682Smarkm break; 13055682Smarkm } 13155682Smarkm /* 13255682Smarkm * "-+" means set these options back to their defaults. 13355682Smarkm * (They may have been set otherwise by previous 13472445Sassar * options.) 13572445Sassar */ 13672445Sassar set_default = (*s == '+'); 13755682Smarkm if (set_default) 13855682Smarkm s++; 13955682Smarkm continue; 14055682Smarkm case '+': 14155682Smarkm /* 14272445Sassar * An option prefixed by a "+" is ungotten, so 14355682Smarkm * that it is interpreted as less commands 144102644Snectar * processed at the start of the first input file. 145 * "++" means process the commands at the start of 146 * EVERY input file. 147 */ 148 plusoption = TRUE; 149 s = optstring(s, &str, propt('+'), NULL); 150 if (*str == '+') 151 every_first_cmd = save(++str); 152 else 153 ungetsc(str); 154 continue; 155 case '0': case '1': case '2': case '3': case '4': 156 case '5': case '6': case '7': case '8': case '9': 157 /* 158 * Special "more" compatibility form "-<number>" 159 * instead of -z<number> to set the scrolling 160 * window size. 161 */ 162 s--; 163 optc = 'z'; 164 break; 165 case 'n': 166 if (less_is_more) 167 optc = 'z'; 168 break; 169 } 170 171 /* 172 * Not a special case. 173 * Look up the option letter in the option table. 174 */ 175 err = 0; 176 if (optname == NULL) 177 { 178 printopt = propt(optc); 179 lc = ASCII_IS_LOWER(optc); 180 o = findopt(optc); 181 } else 182 { 183 printopt = optname; 184 lc = ASCII_IS_LOWER(optname[0]); 185 o = findopt_name(&optname, NULL, &err); 186 s = optname; 187 optname = NULL; 188 if (*s == '\0' || *s == ' ') 189 { 190 /* 191 * The option name matches exactly. 192 */ 193 ; 194 } else if (*s == '=') 195 { 196 /* 197 * The option name is followed by "=value". 198 */ 199 if (o != NULL && 200 (o->otype & OTYPE) != STRING && 201 (o->otype & OTYPE) != NUMBER) 202 { 203 parg.p_string = printopt; 204 error("The %s option should not be followed by =", 205 &parg); 206 quit(QUIT_ERROR); 207 } 208 s++; 209 } else 210 { 211 /* 212 * The specified name is longer than the 213 * real option name. 214 */ 215 o = NULL; 216 } 217 } 218 if (o == NULL) 219 { 220 parg.p_string = printopt; 221 if (err == OPT_AMBIG) 222 error("%s is an ambiguous abbreviation (\"less --help\" for help)", 223 &parg); 224 else 225 error("There is no %s option (\"less --help\" for help)", 226 &parg); 227 quit(QUIT_ERROR); 228 } 229 230 str = NULL; 231 switch (o->otype & OTYPE) 232 { 233 case BOOL: 234 if (set_default) 235 *(o->ovar) = o->odefault; 236 else 237 *(o->ovar) = ! o->odefault; 238 break; 239 case TRIPLE: 240 if (set_default) 241 *(o->ovar) = o->odefault; 242 else 243 *(o->ovar) = flip_triple(o->odefault, lc); 244 break; 245 case STRING: 246 if (*s == '\0') 247 { 248 /* 249 * Set pendopt and return. 250 * We will get the string next time 251 * scan_option is called. 252 */ 253 pendopt = o; 254 return; 255 } 256 /* 257 * Don't do anything here. 258 * All processing of STRING options is done by 259 * the handling function. 260 */ 261 while (*s == ' ') 262 s++; 263 s = optstring(s, &str, printopt, o->odesc[1]); 264 break; 265 case NUMBER: 266 if (*s == '\0') 267 { 268 pendopt = o; 269 return; 270 } 271 *(o->ovar) = getnum(&s, printopt, (int*)NULL); 272 break; 273 } 274 /* 275 * If the option has a handling function, call it. 276 */ 277 if (o->ofunc != NULL) 278 (*o->ofunc)(INIT, str); 279 } 280} 281 282/* 283 * Toggle command line flags from within the program. 284 * Used by the "-" and "_" commands. 285 * how_toggle may be: 286 * OPT_NO_TOGGLE just report the current setting, without changing it. 287 * OPT_TOGGLE invert the current setting 288 * OPT_UNSET set to the default value 289 * OPT_SET set to the inverse of the default value 290 */ 291 public void 292toggle_option(o, lower, s, how_toggle) 293 struct loption *o; 294 int lower; 295 char *s; 296 int how_toggle; 297{ 298 register int num; 299 int no_prompt; 300 int err; 301 PARG parg; 302 303 no_prompt = (how_toggle & OPT_NO_PROMPT); 304 how_toggle &= ~OPT_NO_PROMPT; 305 306 if (o == NULL) 307 { 308 error("No such option", NULL_PARG); 309 return; 310 } 311 312 if (how_toggle == OPT_TOGGLE && (o->otype & NO_TOGGLE)) 313 { 314 parg.p_string = opt_desc(o); 315 error("Cannot change the %s option", &parg); 316 return; 317 } 318 319 if (how_toggle == OPT_NO_TOGGLE && (o->otype & NO_QUERY)) 320 { 321 parg.p_string = opt_desc(o); 322 error("Cannot query the %s option", &parg); 323 return; 324 } 325 326 /* 327 * Check for something which appears to be a do_toggle 328 * (because the "-" command was used), but really is not. 329 * This could be a string option with no string, or 330 * a number option with no number. 331 */ 332 switch (o->otype & OTYPE) 333 { 334 case STRING: 335 case NUMBER: 336 if (how_toggle == OPT_TOGGLE && *s == '\0') 337 how_toggle = OPT_NO_TOGGLE; 338 break; 339 } 340 341#if HILITE_SEARCH 342 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT)) 343 repaint_hilite(0); 344#endif 345 346 /* 347 * Now actually toggle (change) the variable. 348 */ 349 if (how_toggle != OPT_NO_TOGGLE) 350 { 351 switch (o->otype & OTYPE) 352 { 353 case BOOL: 354 /* 355 * Boolean. 356 */ 357 switch (how_toggle) 358 { 359 case OPT_TOGGLE: 360 *(o->ovar) = ! *(o->ovar); 361 break; 362 case OPT_UNSET: 363 *(o->ovar) = o->odefault; 364 break; 365 case OPT_SET: 366 *(o->ovar) = ! o->odefault; 367 break; 368 } 369 break; 370 case TRIPLE: 371 /* 372 * Triple: 373 * If user gave the lower case letter, then switch 374 * to 1 unless already 1, in which case make it 0. 375 * If user gave the upper case letter, then switch 376 * to 2 unless already 2, in which case make it 0. 377 */ 378 switch (how_toggle) 379 { 380 case OPT_TOGGLE: 381 *(o->ovar) = flip_triple(*(o->ovar), lower); 382 break; 383 case OPT_UNSET: 384 *(o->ovar) = o->odefault; 385 break; 386 case OPT_SET: 387 *(o->ovar) = flip_triple(o->odefault, lower); 388 break; 389 } 390 break; 391 case STRING: 392 /* 393 * String: don't do anything here. 394 * The handling function will do everything. 395 */ 396 switch (how_toggle) 397 { 398 case OPT_SET: 399 case OPT_UNSET: 400 error("Cannot use \"-+\" or \"--\" for a string option", 401 NULL_PARG); 402 return; 403 } 404 break; 405 case NUMBER: 406 /* 407 * Number: set the variable to the given number. 408 */ 409 switch (how_toggle) 410 { 411 case OPT_TOGGLE: 412 num = getnum(&s, NULL, &err); 413 if (!err) 414 *(o->ovar) = num; 415 break; 416 case OPT_UNSET: 417 *(o->ovar) = o->odefault; 418 break; 419 case OPT_SET: 420 error("Can't use \"-!\" for a numeric option", 421 NULL_PARG); 422 return; 423 } 424 break; 425 } 426 } 427 428 /* 429 * Call the handling function for any special action 430 * specific to this option. 431 */ 432 if (o->ofunc != NULL) 433 (*o->ofunc)((how_toggle==OPT_NO_TOGGLE) ? QUERY : TOGGLE, s); 434 435#if HILITE_SEARCH 436 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT)) 437 chg_hilite(); 438#endif 439 440 if (!no_prompt) 441 { 442 /* 443 * Print a message describing the new setting. 444 */ 445 switch (o->otype & OTYPE) 446 { 447 case BOOL: 448 case TRIPLE: 449 /* 450 * Print the odesc message. 451 */ 452 error(o->odesc[*(o->ovar)], NULL_PARG); 453 break; 454 case NUMBER: 455 /* 456 * The message is in odesc[1] and has a %d for 457 * the value of the variable. 458 */ 459 parg.p_int = *(o->ovar); 460 error(o->odesc[1], &parg); 461 break; 462 case STRING: 463 /* 464 * Message was already printed by the handling function. 465 */ 466 break; 467 } 468 } 469 470 if (how_toggle != OPT_NO_TOGGLE && (o->otype & REPAINT)) 471 screen_trashed = TRUE; 472} 473 474/* 475 * "Toggle" a triple-valued option. 476 */ 477 static int 478flip_triple(val, lc) 479 int val; 480 int lc; 481{ 482 if (lc) 483 return ((val == OPT_ON) ? OPT_OFF : OPT_ON); 484 else 485 return ((val == OPT_ONPLUS) ? OPT_OFF : OPT_ONPLUS); 486} 487 488/* 489 * Determine if an option takes a parameter. 490 */ 491 public int 492opt_has_param(o) 493 struct loption *o; 494{ 495 if (o == NULL) 496 return (0); 497 if (o->otype & (BOOL|TRIPLE|NOVAR|NO_TOGGLE)) 498 return (0); 499 return (1); 500} 501 502/* 503 * Return the prompt to be used for a given option letter. 504 * Only string and number valued options have prompts. 505 */ 506 public char * 507opt_prompt(o) 508 struct loption *o; 509{ 510 if (o == NULL || (o->otype & (STRING|NUMBER)) == 0) 511 return ("?"); 512 return (o->odesc[0]); 513} 514 515/* 516 * Return whether or not there is a string option pending; 517 * that is, if the previous option was a string-valued option letter 518 * (like -P) without a following string. 519 * In that case, the current option is taken to be the string for 520 * the previous option. 521 */ 522 public int 523isoptpending() 524{ 525 return (pendopt != NULL); 526} 527 528/* 529 * Print error message about missing string. 530 */ 531 static void 532nostring(printopt) 533 char *printopt; 534{ 535 PARG parg; 536 parg.p_string = printopt; 537 error("Value is required after %s", &parg); 538} 539 540/* 541 * Print error message if a STRING type option is not followed by a string. 542 */ 543 public void 544nopendopt() 545{ 546 nostring(opt_desc(pendopt)); 547} 548 549/* 550 * Scan to end of string or to an END_OPTION_STRING character. 551 * In the latter case, replace the char with a null char. 552 * Return a pointer to the remainder of the string, if any. 553 */ 554 static char * 555optstring(s, p_str, printopt, validchars) 556 char *s; 557 char **p_str; 558 char *printopt; 559 char *validchars; 560{ 561 register char *p; 562 563 if (*s == '\0') 564 { 565 nostring(printopt); 566 quit(QUIT_ERROR); 567 } 568 *p_str = s; 569 for (p = s; *p != '\0'; p++) 570 { 571 if (*p == END_OPTION_STRING || 572 (validchars != NULL && strchr(validchars, *p) == NULL)) 573 { 574 switch (*p) 575 { 576 case END_OPTION_STRING: 577 case ' ': case '\t': case '-': 578 /* Replace the char with a null to terminate string. */ 579 *p++ = '\0'; 580 break; 581 default: 582 /* Cannot replace char; make a copy of the string. */ 583 *p_str = (char *) ecalloc(p-s+1, sizeof(char)); 584 strncpy(*p_str, s, p-s); 585 (*p_str)[p-s] = '\0'; 586 break; 587 } 588 break; 589 } 590 } 591 return (p); 592} 593 594/* 595 */ 596 static int 597num_error(printopt, errp) 598 char *printopt; 599 int *errp; 600{ 601 PARG parg; 602 603 if (errp != NULL) 604 { 605 *errp = TRUE; 606 return (-1); 607 } 608 if (printopt != NULL) 609 { 610 parg.p_string = printopt; 611 error("Number is required after %s", &parg); 612 } 613 quit(QUIT_ERROR); 614 /* NOTREACHED */ 615 return (-1); 616} 617 618/* 619 * Translate a string into a number. 620 * Like atoi(), but takes a pointer to a char *, and updates 621 * the char * to point after the translated number. 622 */ 623 public int 624getnum(sp, printopt, errp) 625 char **sp; 626 char *printopt; 627 int *errp; 628{ 629 register char *s; 630 register int n; 631 register int neg; 632 633 s = skipsp(*sp); 634 neg = FALSE; 635 if (*s == '-') 636 { 637 neg = TRUE; 638 s++; 639 } 640 if (*s < '0' || *s > '9') 641 return (num_error(printopt, errp)); 642 643 n = 0; 644 while (*s >= '0' && *s <= '9') 645 n = 10 * n + *s++ - '0'; 646 *sp = s; 647 if (errp != NULL) 648 *errp = FALSE; 649 if (neg) 650 n = -n; 651 return (n); 652} 653 654/* 655 * Translate a string into a fraction, represented by the part of a 656 * number which would follow a decimal point. 657 * The value of the fraction is returned as parts per NUM_FRAC_DENOM. 658 * That is, if "n" is returned, the fraction intended is n/NUM_FRAC_DENOM. 659 */ 660 public long 661getfraction(sp, printopt, errp) 662 char **sp; 663 char *printopt; 664 int *errp; 665{ 666 register char *s; 667 long frac = 0; 668 int fraclen = 0; 669 670 s = skipsp(*sp); 671 if (*s < '0' || *s > '9') 672 return (num_error(printopt, errp)); 673 674 for ( ; *s >= '0' && *s <= '9'; s++) 675 { 676 frac = (frac * 10) + (*s - '0'); 677 fraclen++; 678 } 679 if (fraclen > NUM_LOG_FRAC_DENOM) 680 while (fraclen-- > NUM_LOG_FRAC_DENOM) 681 frac /= 10; 682 else 683 while (fraclen++ < NUM_LOG_FRAC_DENOM) 684 frac *= 10; 685 *sp = s; 686 if (errp != NULL) 687 *errp = FALSE; 688 return (frac); 689} 690 691 692/* 693 * Get the value of the -e flag. 694 */ 695 public int 696get_quit_at_eof() 697{ 698 if (!less_is_more) 699 return quit_at_eof; 700 /* When less_is_more is set, the -e flag semantics are different. */ 701 return quit_at_eof ? OPT_ON : OPT_ONPLUS; 702} 703