1 /* 2 * Copyright (C) 1984-2000 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 option *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 char *every_first_cmd; 33 34 /* 35 * Scan an argument (either from the command line or from the 36 * LESS environment variable) and process it. 37 */ 38 public void 39 scan_option(s) 40 char *s; 41 { 42 register struct option *o; 43 register int optc; 44 char *optname; 45 char *printopt; 46 char *str; 47 int set_default; 48 int lc; 49 int err; 50 PARG parg; 51 52 if (s == NULL) 53 return; 54 55 /* 56 * If we have a pending option which requires an argument, 57 * handle it now. 58 * This happens if the previous option was, for example, "-P" 59 * without a following string. In that case, the current 60 * option is simply the argument for the previous option. 61 */ 62 if (pendopt != NULL) 63 { 64 switch (pendopt->otype & OTYPE) 65 { 66 case STRING: 67 (*pendopt->ofunc)(INIT, s); 68 break; 69 case NUMBER: 70 printopt = propt(pendopt->oletter); 71 *(pendopt->ovar) = getnum(&s, printopt, (int*)NULL); 72 break; 73 } 74 pendopt = NULL; 75 return; 76 } 77 78 set_default = FALSE; 79 optname = NULL; 80 81 while (*s != '\0') 82 { 83 /* 84 * Check some special cases first. 85 */ 86 switch (optc = *s++) 87 { 88 case ' ': 89 case '\t': 90 case END_OPTION_STRING: 91 continue; 92 case '-': 93 /* 94 * "--" indicates an option name instead of a letter. 95 */ 96 if (*s == '-') 97 { 98 optname = ++s; 99 break; 100 } 101 /* 102 * "-+" means set these options back to their defaults. 103 * (They may have been set otherwise by previous 104 * options.) 105 */ 106 set_default = (*s == '+'); 107 if (set_default) 108 s++; 109 continue; 110 case '+': 111 /* 112 * An option prefixed by a "+" is ungotten, so 113 * that it is interpreted as less commands 114 * processed at the start of the first input file. 115 * "++" means process the commands at the start of 116 * EVERY input file. 117 */ 118 plusoption = TRUE; 119 str = s; 120 s = optstring(s, propt('+'), NULL); 121 if (*str == '+') 122 every_first_cmd = save(++str); 123 else 124 ungetsc(str); 125 continue; 126 case '0': case '1': case '2': case '3': case '4': 127 case '5': case '6': case '7': case '8': case '9': 128 /* 129 * Special "more" compatibility form "-<number>" 130 * instead of -z<number> to set the scrolling 131 * window size. 132 */ 133 s--; 134 optc = 'z'; 135 break; 136 } 137 138 /* 139 * Not a special case. 140 * Look up the option letter in the option table. 141 */ 142 err = 0; 143 if (optname == NULL) 144 { 145 printopt = propt(optc); 146 lc = SIMPLE_IS_LOWER(optc); 147 o = findopt(optc); 148 } else 149 { 150 printopt = optname; 151 lc = SIMPLE_IS_LOWER(optname[0]); 152 o = findopt_name(&optname, NULL, &err); 153 s = optname; 154 optname = NULL; 155 if (*s == '\0' || *s == ' ') 156 { 157 /* 158 * The option name matches exactly. 159 */ 160 ; 161 } else if (*s == '=') 162 { 163 /* 164 * The option name is followed by "=value". 165 */ 166 if (o != NULL && 167 (o->otype & OTYPE) != STRING && 168 (o->otype & OTYPE) != NUMBER) 169 { 170 parg.p_string = printopt; 171 error("The %s option should not be followed by =", 172 &parg); 173 quit(QUIT_ERROR); 174 } 175 s++; 176 } else 177 { 178 /* 179 * The specified name is longer than the 180 * real option name. 181 */ 182 o = NULL; 183 } 184 } 185 if (o == NULL) 186 { 187 parg.p_string = printopt; 188 if (err == OPT_AMBIG) 189 error("%s is an ambiguous abbreviation (\"less --help\" for help)", 190 &parg); 191 else 192 error("There is no %s option (\"less --help\" for help)", 193 &parg); 194 quit(QUIT_ERROR); 195 } 196 197 str = NULL; 198 switch (o->otype & OTYPE) 199 { 200 case BOOL: 201 if (set_default) 202 *(o->ovar) = o->odefault; 203 else 204 *(o->ovar) = ! o->odefault; 205 break; 206 case TRIPLE: 207 if (set_default) 208 *(o->ovar) = o->odefault; 209 else 210 *(o->ovar) = flip_triple(o->odefault, lc); 211 break; 212 case STRING: 213 if (*s == '\0') 214 { 215 /* 216 * Set pendopt and return. 217 * We will get the string next time 218 * scan_option is called. 219 */ 220 pendopt = o; 221 return; 222 } 223 /* 224 * Don't do anything here. 225 * All processing of STRING options is done by 226 * the handling function. 227 */ 228 str = s; 229 s = optstring(s, printopt, o->odesc[1]); 230 break; 231 case NUMBER: 232 if (*s == '\0') 233 { 234 pendopt = o; 235 return; 236 } 237 *(o->ovar) = getnum(&s, printopt, (int*)NULL); 238 break; 239 } 240 /* 241 * If the option has a handling function, call it. 242 */ 243 if (o->ofunc != NULL) 244 (*o->ofunc)(INIT, str); 245 } 246 } 247 248 /* 249 * Toggle command line flags from within the program. 250 * Used by the "-" and "_" commands. 251 * how_toggle may be: 252 * OPT_NO_TOGGLE just report the current setting, without changing it. 253 * OPT_TOGGLE invert the current setting 254 * OPT_UNSET set to the default value 255 * OPT_SET set to the inverse of the default value 256 */ 257 public void 258 toggle_option(c, s, how_toggle) 259 int c; 260 char *s; 261 int how_toggle; 262 { 263 register struct option *o; 264 register int num; 265 int no_prompt; 266 int err; 267 PARG parg; 268 269 no_prompt = (how_toggle & OPT_NO_PROMPT); 270 how_toggle &= ~OPT_NO_PROMPT; 271 272 /* 273 * Look up the option letter in the option table. 274 */ 275 o = findopt(c); 276 if (o == NULL) 277 { 278 parg.p_string = propt(c); 279 error("There is no %s option", &parg); 280 return; 281 } 282 283 if (how_toggle == OPT_TOGGLE && (o->otype & NO_TOGGLE)) 284 { 285 parg.p_string = propt(c); 286 error("Cannot change the %s option", &parg); 287 return; 288 } 289 290 if (how_toggle == OPT_NO_TOGGLE && (o->otype & NO_QUERY)) 291 { 292 parg.p_string = propt(c); 293 error("Cannot query the %s option", &parg); 294 return; 295 } 296 297 /* 298 * Check for something which appears to be a do_toggle 299 * (because the "-" command was used), but really is not. 300 * This could be a string option with no string, or 301 * a number option with no number. 302 */ 303 switch (o->otype & OTYPE) 304 { 305 case STRING: 306 case NUMBER: 307 if (how_toggle == OPT_TOGGLE && *s == '\0') 308 how_toggle = OPT_NO_TOGGLE; 309 break; 310 } 311 312 #if HILITE_SEARCH 313 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT)) 314 repaint_hilite(0); 315 #endif 316 317 /* 318 * Now actually toggle (change) the variable. 319 */ 320 if (how_toggle != OPT_NO_TOGGLE) 321 { 322 switch (o->otype & OTYPE) 323 { 324 case BOOL: 325 /* 326 * Boolean. 327 */ 328 switch (how_toggle) 329 { 330 case OPT_TOGGLE: 331 *(o->ovar) = ! *(o->ovar); 332 break; 333 case OPT_UNSET: 334 *(o->ovar) = o->odefault; 335 break; 336 case OPT_SET: 337 *(o->ovar) = ! o->odefault; 338 break; 339 } 340 break; 341 case TRIPLE: 342 /* 343 * Triple: 344 * If user gave the lower case letter, then switch 345 * to 1 unless already 1, in which case make it 0. 346 * If user gave the upper case letter, then switch 347 * to 2 unless already 2, in which case make it 0. 348 */ 349 switch (how_toggle) 350 { 351 case OPT_TOGGLE: 352 *(o->ovar) = flip_triple(*(o->ovar), 353 islower(c)); 354 break; 355 case OPT_UNSET: 356 *(o->ovar) = o->odefault; 357 break; 358 case OPT_SET: 359 *(o->ovar) = flip_triple(o->odefault, 360 islower(c)); 361 break; 362 } 363 break; 364 case STRING: 365 /* 366 * String: don't do anything here. 367 * The handling function will do everything. 368 */ 369 switch (how_toggle) 370 { 371 case OPT_SET: 372 case OPT_UNSET: 373 error("Cannot use \"-+\" or \"--\" for a string option", 374 NULL_PARG); 375 return; 376 } 377 break; 378 case NUMBER: 379 /* 380 * Number: set the variable to the given number. 381 */ 382 switch (how_toggle) 383 { 384 case OPT_TOGGLE: 385 num = getnum(&s, '\0', &err); 386 if (!err) 387 *(o->ovar) = num; 388 break; 389 case OPT_UNSET: 390 *(o->ovar) = o->odefault; 391 break; 392 case OPT_SET: 393 error("Can't use \"-!\" for a numeric option", 394 NULL_PARG); 395 return; 396 } 397 break; 398 } 399 } 400 401 /* 402 * Call the handling function for any special action 403 * specific to this option. 404 */ 405 if (o->ofunc != NULL) 406 (*o->ofunc)((how_toggle==OPT_NO_TOGGLE) ? QUERY : TOGGLE, s); 407 408 #if HILITE_SEARCH 409 if (how_toggle != OPT_NO_TOGGLE && (o->otype & HL_REPAINT)) 410 chg_hilite(); 411 #endif 412 413 if (!no_prompt) 414 { 415 /* 416 * Print a message describing the new setting. 417 */ 418 switch (o->otype & OTYPE) 419 { 420 case BOOL: 421 case TRIPLE: 422 /* 423 * Print the odesc message. 424 */ 425 error(o->odesc[*(o->ovar)], NULL_PARG); 426 break; 427 case NUMBER: 428 /* 429 * The message is in odesc[1] and has a %d for 430 * the value of the variable. 431 */ 432 parg.p_int = *(o->ovar); 433 error(o->odesc[1], &parg); 434 break; 435 case STRING: 436 /* 437 * Message was already printed by the handling function. 438 */ 439 break; 440 } 441 } 442 443 if (how_toggle != OPT_NO_TOGGLE && (o->otype & REPAINT)) 444 screen_trashed = TRUE; 445 } 446 447 /* 448 * "Toggle" a triple-valued option. 449 */ 450 static int 451 flip_triple(val, lc) 452 int val; 453 int lc; 454 { 455 if (lc) 456 return ((val == OPT_ON) ? OPT_OFF : OPT_ON); 457 else 458 return ((val == OPT_ONPLUS) ? OPT_OFF : OPT_ONPLUS); 459 } 460 461 /* 462 * Return a string suitable for printing as the "name" of an option. 463 * For example, if the option letter is 'x', just return "-x". 464 */ 465 static char * 466 propt(c) 467 int c; 468 { 469 static char buf[8]; 470 471 sprintf(buf, "-%s", prchar(c)); 472 return (buf); 473 } 474 475 /* 476 * Determine if an option is a single character option (BOOL or TRIPLE), 477 * or if it a multi-character option (NUMBER). 478 */ 479 public int 480 single_char_option(c) 481 int c; 482 { 483 register struct option *o; 484 485 o = findopt(c); 486 if (o == NULL) 487 return (TRUE); 488 return ((o->otype & (BOOL|TRIPLE|NOVAR|NO_TOGGLE)) != 0); 489 } 490 491 /* 492 * Return the prompt to be used for a given option letter. 493 * Only string and number valued options have prompts. 494 */ 495 public char * 496 opt_prompt(c) 497 int c; 498 { 499 register struct option *o; 500 501 o = findopt(c); 502 if (o == NULL || (o->otype & (STRING|NUMBER)) == 0) 503 return (NULL); 504 return (o->odesc[0]); 505 } 506 507 /* 508 * Return whether or not there is a string option pending; 509 * that is, if the previous option was a string-valued option letter 510 * (like -P) without a following string. 511 * In that case, the current option is taken to be the string for 512 * the previous option. 513 */ 514 public int 515 isoptpending() 516 { 517 return (pendopt != NULL); 518 } 519 520 /* 521 * Print error message about missing string. 522 */ 523 static void 524 nostring(printopt) 525 char *printopt; 526 { 527 PARG parg; 528 parg.p_string = printopt; 529 error("Value is required after %s", &parg); 530 } 531 532 /* 533 * Print error message if a STRING type option is not followed by a string. 534 */ 535 public void 536 nopendopt() 537 { 538 nostring(propt(pendopt->oletter)); 539 } 540 541 /* 542 * Scan to end of string or to an END_OPTION_STRING character. 543 * In the latter case, replace the char with a null char. 544 * Return a pointer to the remainder of the string, if any. 545 */ 546 static char * 547 optstring(s, printopt, validchars) 548 char *s; 549 char *printopt; 550 char *validchars; 551 { 552 register char *p; 553 PARG parg; 554 555 if (*s == '\0') 556 { 557 nostring(printopt); 558 quit(QUIT_ERROR); 559 } 560 for (p = s; *p != '\0'; p++) 561 if (*p == END_OPTION_STRING || 562 (validchars != NULL && strchr(validchars, *p) == NULL)) 563 { 564 switch (*p) 565 { 566 case END_OPTION_STRING: 567 case ' ': case '\t': case '-': 568 break; 569 default: 570 parg.p_string = p; 571 error("Option string needs delimiter before %s", &parg); 572 break; 573 } 574 *p = '\0'; 575 return (p+1); 576 } 577 return (p); 578 } 579 580 /* 581 * Translate a string into a number. 582 * Like atoi(), but takes a pointer to a char *, and updates 583 * the char * to point after the translated number. 584 */ 585 public int 586 getnum(sp, printopt, errp) 587 char **sp; 588 char *printopt; 589 int *errp; 590 { 591 register char *s; 592 register int n; 593 register int neg; 594 PARG parg; 595 596 s = skipsp(*sp); 597 neg = FALSE; 598 if (*s == '-') 599 { 600 neg = TRUE; 601 s++; 602 } 603 if (*s < '0' || *s > '9') 604 { 605 if (errp != NULL) 606 { 607 *errp = TRUE; 608 return (-1); 609 } 610 parg.p_string = printopt; 611 error("Number is required after %s", &parg); 612 quit(QUIT_ERROR); 613 } 614 615 n = 0; 616 while (*s >= '0' && *s <= '9') 617 n = 10 * n + *s++ - '0'; 618 *sp = s; 619 if (errp != NULL) 620 *errp = FALSE; 621 if (neg) 622 n = -n; 623 return (n); 624 } 625