units.c revision 1.13
1 /* $NetBSD: units.c,v 1.13 2003/12/05 22:26:43 mycroft Exp $ */ 2 3 /* 4 * units.c Copyright (c) 1993 by Adrian Mariano (adrian (at) cam.cornell.edu) 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. The name of the author may not be used to endorse or promote products 12 * derived from this software without specific prior written permission. 13 * Disclaimer: This software is provided by the author "as is". The author 14 * shall not be liable for any damages caused in any way by this software. 15 * 16 * I would appreciate (though I do not require) receiving a copy of any 17 * improvements you might make to this program. 18 */ 19 20 #include <ctype.h> 21 #include <err.h> 22 #include <stdio.h> 23 #include <string.h> 24 #include <stdlib.h> 25 #include <unistd.h> 26 27 #include "pathnames.h" 28 29 #define VERSION "1.0" 30 31 #ifndef UNITSFILE 32 #define UNITSFILE _PATH_UNITSLIB 33 #endif 34 35 #define MAXUNITS 1000 36 #define MAXPREFIXES 50 37 38 #define MAXSUBUNITS 500 39 40 #define PRIMITIVECHAR '!' 41 42 char *powerstring = "^"; 43 44 struct { 45 char *uname; 46 char *uval; 47 } unittable[MAXUNITS]; 48 49 struct unittype { 50 char *numerator[MAXSUBUNITS]; 51 char *denominator[MAXSUBUNITS]; 52 double factor; 53 }; 54 55 struct { 56 char *prefixname; 57 char *prefixval; 58 } prefixtable[MAXPREFIXES]; 59 60 61 char *NULLUNIT = ""; 62 63 int unitcount; 64 int prefixcount; 65 66 67 int addsubunit __P((char *[], char *)); 68 int addunit __P((struct unittype *, char *, int)); 69 void cancelunit __P((struct unittype *)); 70 int compare __P((const void *, const void *)); 71 int compareproducts __P((char **, char **)); 72 int compareunits __P((struct unittype *, struct unittype *)); 73 int compareunitsreciprocal __P((struct unittype *, struct unittype *)); 74 int completereduce __P((struct unittype *)); 75 void initializeunit __P((struct unittype *)); 76 int main __P((int, char **)); 77 void readerror __P((int)); 78 void readunits __P((char *)); 79 int reduceproduct __P((struct unittype *, int)); 80 int reduceunit __P((struct unittype *)); 81 void showanswer __P((struct unittype *, struct unittype *)); 82 void showunit __P((struct unittype *)); 83 void sortunit __P((struct unittype *)); 84 void usage __P((void)); 85 void zeroerror __P((void)); 86 char *dupstr __P((char *)); 87 char *lookupunit __P((char *)); 88 89 90 char * 91 dupstr(char *str) 92 { 93 char *ret; 94 95 ret = strdup(str); 96 if (!ret) 97 err(3, "Memory allocation error"); 98 return (ret); 99 } 100 101 102 void 103 readerror(int linenum) 104 { 105 warnx("Error in units file '%s' line %d", UNITSFILE, linenum); 106 } 107 108 109 void 110 readunits(char *userfile) 111 { 112 FILE *unitfile; 113 char line[80], *lineptr; 114 int len, linenum, i; 115 116 unitcount = 0; 117 linenum = 0; 118 119 if (userfile) { 120 unitfile = fopen(userfile, "rt"); 121 if (!unitfile) 122 err(1, "Unable to open units file '%s'", userfile); 123 } 124 else { 125 unitfile = fopen(UNITSFILE, "rt"); 126 if (!unitfile) { 127 char *direc, *env; 128 char filename[1000]; 129 char separator[2]; 130 131 env = getenv("PATH"); 132 if (env) { 133 if (strchr(env, ';')) 134 strlcpy(separator, ";", 135 sizeof(separator)); 136 else 137 strlcpy(separator, ":", 138 sizeof(separator)); 139 direc = strtok(env, separator); 140 while (direc) { 141 strlcpy(filename, "", sizeof(filename)); 142 strlcat(filename, direc, 143 sizeof(filename)); 144 strlcat(filename, "/", 145 sizeof(filename)); 146 strlcat(filename, UNITSFILE, 147 sizeof(filename)); 148 unitfile = fopen(filename, "rt"); 149 if (unitfile) 150 break; 151 direc = strtok(NULL, separator); 152 } 153 } 154 if (!unitfile) 155 errx(1, "Can't find units file '%s'", 156 UNITSFILE); 157 } 158 } 159 while (!feof(unitfile)) { 160 if (!fgets(line, 79, unitfile)) 161 break; 162 linenum++; 163 lineptr = line; 164 if (*lineptr == '/') 165 continue; 166 lineptr += strspn(lineptr, " \n\t"); 167 len = strcspn(lineptr, " \n\t"); 168 lineptr[len] = 0; 169 if (!strlen(lineptr)) 170 continue; 171 if (lineptr[strlen(lineptr) - 1] == '-') { /* it's a prefix */ 172 if (prefixcount == MAXPREFIXES) { 173 warnx("Memory for prefixes exceeded in line %d", 174 linenum); 175 continue; 176 } 177 lineptr[strlen(lineptr) - 1] = 0; 178 prefixtable[prefixcount].prefixname = dupstr(lineptr); 179 for (i = 0; i < prefixcount; i++) 180 if (!strcmp(prefixtable[i].prefixname, lineptr)) { 181 warnx( 182 "Redefinition of prefix '%s' on line %d ignored", 183 lineptr, linenum); 184 continue; 185 } 186 lineptr += len + 1; 187 if (!strlen(lineptr)) { 188 readerror(linenum); 189 continue; 190 } 191 lineptr += strspn(lineptr, " \n\t"); 192 len = strcspn(lineptr, "\n\t"); 193 lineptr[len] = 0; 194 prefixtable[prefixcount++].prefixval = dupstr(lineptr); 195 } 196 else { /* it's not a prefix */ 197 if (unitcount == MAXUNITS) { 198 warnx("Memory for units exceeded in line %d", 199 linenum); 200 continue; 201 } 202 unittable[unitcount].uname = dupstr(lineptr); 203 for (i = 0; i < unitcount; i++) 204 if (!strcmp(unittable[i].uname, lineptr)) { 205 warnx( 206 "Redefinition of unit '%s' on line %d ignored", 207 lineptr, linenum); 208 continue; 209 } 210 lineptr += len + 1; 211 lineptr += strspn(lineptr, " \n\t"); 212 if (!strlen(lineptr)) { 213 readerror(linenum); 214 continue; 215 } 216 len = strcspn(lineptr, "\n\t"); 217 lineptr[len] = 0; 218 unittable[unitcount++].uval = dupstr(lineptr); 219 } 220 } 221 fclose(unitfile); 222 } 223 224 void 225 initializeunit(struct unittype * theunit) 226 { 227 theunit->factor = 1.0; 228 theunit->numerator[0] = theunit->denominator[0] = NULL; 229 } 230 231 232 int 233 addsubunit(char *product[], char *toadd) 234 { 235 char **ptr; 236 237 for (ptr = product; *ptr && *ptr != NULLUNIT; ptr++); 238 if (ptr >= product + MAXSUBUNITS) { 239 warnx("Memory overflow in unit reduction"); 240 return 1; 241 } 242 if (!*ptr) 243 *(ptr + 1) = 0; 244 *ptr = dupstr(toadd); 245 return 0; 246 } 247 248 249 void 250 showunit(struct unittype * theunit) 251 { 252 char **ptr; 253 int printedslash; 254 int counter = 1; 255 256 printf("\t%.8g", theunit->factor); 257 for (ptr = theunit->numerator; *ptr; ptr++) { 258 if (ptr > theunit->numerator && **ptr && 259 !strcmp(*ptr, *(ptr - 1))) 260 counter++; 261 else { 262 if (counter > 1) 263 printf("%s%d", powerstring, counter); 264 if (**ptr) 265 printf(" %s", *ptr); 266 counter = 1; 267 } 268 } 269 if (counter > 1) 270 printf("%s%d", powerstring, counter); 271 counter = 1; 272 printedslash = 0; 273 for (ptr = theunit->denominator; *ptr; ptr++) { 274 if (ptr > theunit->denominator && **ptr && 275 !strcmp(*ptr, *(ptr - 1))) 276 counter++; 277 else { 278 if (counter > 1) 279 printf("%s%d", powerstring, counter); 280 if (**ptr) { 281 if (!printedslash) 282 printf(" /"); 283 printedslash = 1; 284 printf(" %s", *ptr); 285 } 286 counter = 1; 287 } 288 } 289 if (counter > 1) 290 printf("%s%d", powerstring, counter); 291 printf("\n"); 292 } 293 294 295 void 296 zeroerror() 297 { 298 warnx("Unit reduces to zero"); 299 } 300 301 /* 302 Adds the specified string to the unit. 303 Flip is 0 for adding normally, 1 for adding reciprocal. 304 305 Returns 0 for successful addition, nonzero on error. 306 */ 307 308 int 309 addunit(struct unittype * theunit, char *toadd, int flip) 310 { 311 char *scratch, *savescr; 312 char *item; 313 char *divider, *slash; 314 int doingtop; 315 316 savescr = scratch = dupstr(toadd); 317 for (slash = scratch + 1; *slash; slash++) 318 if (*slash == '-' && 319 (tolower(*(slash - 1)) != 'e' || 320 !strchr(".0123456789", *(slash + 1)))) 321 *slash = ' '; 322 slash = strchr(scratch, '/'); 323 if (slash) 324 *slash = 0; 325 doingtop = 1; 326 do { 327 item = strtok(scratch, " *\t\n/"); 328 while (item) { 329 if (strchr("0123456789.", *item)) { /* item is a number */ 330 double num; 331 332 divider = strchr(item, '|'); 333 if (divider) { 334 *divider = 0; 335 num = atof(item); 336 if (!num) { 337 zeroerror(); 338 return 1; 339 } 340 if (doingtop ^ flip) 341 theunit->factor *= num; 342 else 343 theunit->factor /= num; 344 num = atof(divider + 1); 345 if (!num) { 346 zeroerror(); 347 return 1; 348 } 349 if (doingtop ^ flip) 350 theunit->factor /= num; 351 else 352 theunit->factor *= num; 353 } 354 else { 355 num = atof(item); 356 if (!num) { 357 zeroerror(); 358 return 1; 359 } 360 if (doingtop ^ flip) 361 theunit->factor *= num; 362 else 363 theunit->factor /= num; 364 365 } 366 } 367 else { /* item is not a number */ 368 int repeat = 1; 369 370 if (strchr("23456789", 371 item[strlen(item) - 1])) { 372 repeat = item[strlen(item) - 1] - '0'; 373 item[strlen(item) - 1] = 0; 374 } 375 for (; repeat; repeat--) 376 if (addsubunit(doingtop ^ flip ? theunit->numerator : theunit->denominator, item)) 377 return 1; 378 } 379 item = strtok(NULL, " *\t/\n"); 380 } 381 doingtop--; 382 if (slash) { 383 scratch = slash + 1; 384 } 385 else 386 doingtop--; 387 } while (doingtop >= 0); 388 free(savescr); 389 return 0; 390 } 391 392 393 int 394 compare(const void *item1, const void *item2) 395 { 396 return strcmp(*(char **) item1, *(char **) item2); 397 } 398 399 400 void 401 sortunit(struct unittype * theunit) 402 { 403 char **ptr; 404 int count; 405 406 for (count = 0, ptr = theunit->numerator; *ptr; ptr++, count++); 407 qsort(theunit->numerator, count, sizeof(char *), compare); 408 for (count = 0, ptr = theunit->denominator; *ptr; ptr++, count++); 409 qsort(theunit->denominator, count, sizeof(char *), compare); 410 } 411 412 413 void 414 cancelunit(struct unittype * theunit) 415 { 416 char **den, **num; 417 int comp; 418 419 den = theunit->denominator; 420 num = theunit->numerator; 421 422 while (*num && *den) { 423 comp = strcmp(*den, *num); 424 if (!comp) { 425 /* if (*den!=NULLUNIT) free(*den); 426 if (*num!=NULLUNIT) free(*num);*/ 427 *den++ = NULLUNIT; 428 *num++ = NULLUNIT; 429 } 430 else if (comp < 0) 431 den++; 432 else 433 num++; 434 } 435 } 436 437 438 439 440 /* 441 Looks up the definition for the specified unit. 442 Returns a pointer to the definition or a null pointer 443 if the specified unit does not appear in the units table. 444 */ 445 446 static char buffer[100]; /* buffer for lookupunit answers with 447 prefixes */ 448 449 char * 450 lookupunit(char *unit) 451 { 452 int i; 453 char *copy; 454 455 for (i = 0; i < unitcount; i++) { 456 if (!strcmp(unittable[i].uname, unit)) 457 return unittable[i].uval; 458 } 459 460 if (unit[strlen(unit) - 1] == '^') { 461 copy = dupstr(unit); 462 copy[strlen(copy) - 1] = 0; 463 for (i = 0; i < unitcount; i++) { 464 if (!strcmp(unittable[i].uname, copy)) { 465 strlcpy(buffer, copy, sizeof(buffer)); 466 free(copy); 467 return buffer; 468 } 469 } 470 free(copy); 471 } 472 if (unit[strlen(unit) - 1] == 's') { 473 copy = dupstr(unit); 474 copy[strlen(copy) - 1] = 0; 475 for (i = 0; i < unitcount; i++) { 476 if (!strcmp(unittable[i].uname, copy)) { 477 strlcpy(buffer, copy, sizeof(buffer)); 478 free(copy); 479 return buffer; 480 } 481 } 482 if (copy[strlen(copy) - 1] == 'e') { 483 copy[strlen(copy) - 1] = 0; 484 for (i = 0; i < unitcount; i++) { 485 if (!strcmp(unittable[i].uname, copy)) { 486 strlcpy(buffer, copy, sizeof(buffer)); 487 free(copy); 488 return buffer; 489 } 490 } 491 } 492 free(copy); 493 } 494 for (i = 0; i < prefixcount; i++) { 495 if (!strncmp(prefixtable[i].prefixname, unit, 496 strlen(prefixtable[i].prefixname))) { 497 unit += strlen(prefixtable[i].prefixname); 498 if (!strlen(unit) || lookupunit(unit)) { 499 strlcpy(buffer, prefixtable[i].prefixval, 500 sizeof(buffer)); 501 strlcat(buffer, " ", sizeof(buffer)); 502 strlcat(buffer, unit, sizeof(buffer)); 503 return buffer; 504 } 505 } 506 } 507 return 0; 508 } 509 510 511 512 /* 513 reduces a product of symbolic units to primitive units. 514 The three low bits are used to return flags: 515 516 bit 0 (1) set on if reductions were performed without error. 517 bit 1 (2) set on if no reductions are performed. 518 bit 2 (4) set on if an unknown unit is discovered. 519 */ 520 521 522 #define ERROR 4 523 524 int 525 reduceproduct(struct unittype * theunit, int flip) 526 { 527 528 char *toadd; 529 char **product; 530 int didsomething = 2; 531 532 if (flip) 533 product = theunit->denominator; 534 else 535 product = theunit->numerator; 536 537 for (; *product; product++) { 538 539 for (;;) { 540 if (!strlen(*product)) 541 break; 542 toadd = lookupunit(*product); 543 if (!toadd) { 544 printf("unknown unit '%s'\n", *product); 545 return ERROR; 546 } 547 if (strchr(toadd, PRIMITIVECHAR)) 548 break; 549 didsomething = 1; 550 if (*product != NULLUNIT) { 551 free(*product); 552 *product = NULLUNIT; 553 } 554 if (addunit(theunit, toadd, flip)) 555 return ERROR; 556 } 557 } 558 return didsomething; 559 } 560 561 562 /* 563 Reduces numerator and denominator of the specified unit. 564 Returns 0 on success, or 1 on unknown unit error. 565 */ 566 567 int 568 reduceunit(struct unittype * theunit) 569 { 570 int ret; 571 572 ret = 1; 573 while (ret & 1) { 574 ret = reduceproduct(theunit, 0) | reduceproduct(theunit, 1); 575 if (ret & 4) 576 return 1; 577 } 578 return 0; 579 } 580 581 582 int 583 compareproducts(char **one, char **two) 584 { 585 while (*one || *two) { 586 if (!*one && *two != NULLUNIT) 587 return 1; 588 if (!*two && *one != NULLUNIT) 589 return 1; 590 if (*one == NULLUNIT) 591 one++; 592 else if (*two == NULLUNIT) 593 two++; 594 else if (strcmp(*one, *two)) 595 return 1; 596 else 597 one++, two++; 598 } 599 return 0; 600 } 601 602 603 /* Return zero if units are compatible, nonzero otherwise */ 604 605 int 606 compareunits(struct unittype * first, struct unittype * second) 607 { 608 return 609 compareproducts(first->numerator, second->numerator) || 610 compareproducts(first->denominator, second->denominator); 611 } 612 613 int 614 compareunitsreciprocal(struct unittype * first, struct unittype * second) 615 { 616 return 617 compareproducts(first->numerator, second->denominator) || 618 compareproducts(first->denominator, second->numerator); 619 } 620 621 622 int 623 completereduce(struct unittype * unit) 624 { 625 if (reduceunit(unit)) 626 return 1; 627 sortunit(unit); 628 cancelunit(unit); 629 return 0; 630 } 631 632 633 void 634 showanswer(struct unittype * have, struct unittype * want) 635 { 636 if (compareunits(have, want)) { 637 if (compareunitsreciprocal(have, want)) { 638 printf("conformability error\n"); 639 showunit(have); 640 showunit(want); 641 } else { 642 printf("\treciprocal conversion\n"); 643 printf("\t* %.8g\n\t/ %.8g\n", 1 / (have->factor * want->factor), 644 want->factor * have->factor); 645 } 646 } 647 else 648 printf("\t* %.8g\n\t/ %.8g\n", have->factor / want->factor, 649 want->factor / have->factor); 650 } 651 652 653 void 654 usage() 655 { 656 fprintf(stderr, 657 "\nunits [-f unitsfile] [-q] [-v] [from-unit to-unit]\n"); 658 fprintf(stderr, "\n -f specify units file\n"); 659 fprintf(stderr, " -q suppress prompting (quiet)\n"); 660 fprintf(stderr, " -v print version number\n"); 661 exit(3); 662 } 663 664 665 int 666 main(int argc, char **argv) 667 { 668 669 struct unittype have, want; 670 char havestr[81], wantstr[81]; 671 int optchar; 672 char *userfile = 0; 673 int quiet = 0; 674 675 while ((optchar = getopt(argc, argv, "vqf:")) != -1) { 676 switch (optchar) { 677 case 'f': 678 userfile = optarg; 679 break; 680 case 'q': 681 quiet = 1; 682 break; 683 case 'v': 684 fprintf(stderr, "\n units version %s Copyright (c) 1993 by Adrian Mariano\n", 685 VERSION); 686 fprintf(stderr, " This program may be freely distributed\n"); 687 usage(); 688 default: 689 usage(); 690 break; 691 } 692 } 693 694 argc -= optind; 695 argv += optind; 696 697 if (argc != 3 && argc != 2 && argc != 0) 698 usage(); 699 700 readunits(userfile); 701 702 if (argc == 3) { 703 strlcpy(havestr, argv[0], sizeof(havestr)); 704 strlcat(havestr, " ", sizeof(havestr)); 705 strlcat(havestr, argv[1], sizeof(havestr)); 706 argc--; 707 argv++; 708 argv[0] = havestr; 709 } 710 711 if (argc == 2) { 712 strlcpy(havestr, argv[0], sizeof(havestr)); 713 strlcpy(wantstr, argv[1], sizeof(wantstr)); 714 initializeunit(&have); 715 addunit(&have, havestr, 0); 716 completereduce(&have); 717 initializeunit(&want); 718 addunit(&want, wantstr, 0); 719 completereduce(&want); 720 showanswer(&have, &want); 721 } 722 else { 723 if (!quiet) 724 printf("%d units, %d prefixes\n\n", unitcount, 725 prefixcount); 726 for (;;) { 727 do { 728 initializeunit(&have); 729 if (!quiet) 730 printf("You have: "); 731 if (!fgets(havestr, 80, stdin)) { 732 if (!quiet) 733 putchar('\n'); 734 exit(0); 735 } 736 } while (addunit(&have, havestr, 0) || 737 completereduce(&have)); 738 do { 739 initializeunit(&want); 740 if (!quiet) 741 printf("You want: "); 742 if (!fgets(wantstr, 80, stdin)) { 743 if (!quiet) 744 putchar('\n'); 745 exit(0); 746 } 747 } while (addunit(&want, wantstr, 0) || 748 completereduce(&want)); 749 showanswer(&have, &want); 750 } 751 } 752 return (0); 753 } 754
Indexes created Fri Sep 26 08:10:20 GMT 2025