usr.bin/units/units.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * units.c   Copyright (c) 1993 by Adrian Mariano (adrian@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 #ifndef lint
  21 static const char rcsid[] =
  22   "$FreeBSD$";
  23 #endif /* not lint */
  24
  25 #include <ctype.h>
  26 #include <err.h>
  27 #include <errno.h>
  28 #include <histedit.h>
  29 #include <getopt.h>
  30 #include <stdbool.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <unistd.h>
  35
  36 #include <capsicum_helpers.h>
  37
  38 #ifndef UNITSFILE
  39 #define UNITSFILE "/usr/share/misc/definitions.units"
  40 #endif
  41
  42 #define MAXUNITS 1000
  43 #define MAXPREFIXES 100
  44
  45 #define MAXSUBUNITS 500
  46
  47 #define PRIMITIVECHAR '!'
  48
  49 static const char *powerstring = "^";
  50 static const char *numfmt = "%.8g";
  51
  52 static struct {
  53         char *uname;
  54         char *uval;
  55 }      unittable[MAXUNITS];
  56
  57 struct unittype {
  58         char *numerator[MAXSUBUNITS];
  59         char *denominator[MAXSUBUNITS];
  60         double factor;
  61         double offset;
  62         int quantity;
  63 };
  64
  65 static struct {
  66         char *prefixname;
  67         char *prefixval;
  68 }      prefixtable[MAXPREFIXES];
  69
  70
  71 static char NULLUNIT[] = "";
  72
  73 #define SEPARATOR      ":"
  74
  75 static int unitcount;
  76 static int prefixcount;
  77 static bool verbose = false;
  78 static bool terse = false;
  79 static const char * outputformat;
  80 static const char * havestr;
  81 static const char * wantstr;
  82
  83 static int       addsubunit(char *product[], char *toadd);
  84 static int       addunit(struct unittype *theunit, const char *toadd, int flip, int quantity);
  85 static void      cancelunit(struct unittype * theunit);
  86 static int       compare(const void *item1, const void *item2);
  87 static int       compareproducts(char **one, char **two);
  88 static int       compareunits(struct unittype * first, struct unittype * second);
  89 static int       completereduce(struct unittype * unit);
  90 static char     *dupstr(const char *str);
  91 static void      initializeunit(struct unittype * theunit);
  92 static char     *lookupunit(const char *unit);
  93 static void      readunits(const char *userfile);
  94 static int       reduceproduct(struct unittype * theunit, int flip);
  95 static int       reduceunit(struct unittype * theunit);
  96 static void      showanswer(struct unittype * have, struct unittype * want);
  97 static void      showunit(struct unittype * theunit);
  98 static void      sortunit(struct unittype * theunit);
  99 static void      usage(void);
 100 static void      zeroerror(void);
 101
 102 static const char* promptstr = "";
 103
 104 static const char * prompt(EditLine *e __unused) {
 105         return promptstr;
 106 }
 107
 108 static char *
 109 dupstr(const char *str)
 110 {
 111         char *ret;
 112
 113         ret = strdup(str);
 114         if (!ret)
 115                 err(3, "dupstr");
 116         return (ret);
 117 }
 118
 119
 120 static void
 121 readunits(const char *userfile)
 122 {
 123         FILE *unitfile;
 124         char line[512], *lineptr;
 125         int len, linenum, i;
 126         cap_rights_t unitfilerights;
 127
 128         unitcount = 0;
 129         linenum = 0;
 130
 131         if (userfile) {
 132                 unitfile = fopen(userfile, "r");
 133                 if (!unitfile)
 134                         errx(1, "unable to open units file '%s'", userfile);
 135         }
 136         else {
 137                 unitfile = fopen(UNITSFILE, "r");
 138                 if (!unitfile) {
 139                         char *direc, *env;
 140                         char filename[1000];
 141
 142                         env = getenv("PATH");
 143                         if (env) {
 144                                 direc = strtok(env, SEPARATOR);
 145                                 while (direc) {
 146                                         snprintf(filename, sizeof(filename),
 147                                             "%s/%s", direc, UNITSFILE);
 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'", UNITSFILE);
 156                 }
 157         }
 158         cap_rights_init(&unitfilerights, CAP_READ, CAP_FSTAT);
 159         if (caph_rights_limit(fileno(unitfile), &unitfilerights) < 0)
 160                 err(1, "cap_rights_limit() failed");
 161         while (!feof(unitfile)) {
 162                 if (!fgets(line, sizeof(line), unitfile))
 163                         break;
 164                 linenum++;
 165                 lineptr = line;
 166                 if (*lineptr == '/' || *lineptr == '#')
 167                         continue;
 168                 lineptr += strspn(lineptr, " \n\t");
 169                 len = strcspn(lineptr, " \n\t");
 170                 lineptr[len] = 0;
 171                 if (!strlen(lineptr))
 172                         continue;
 173                 if (lineptr[strlen(lineptr) - 1] == '-') { /* it's a prefix */
 174                         if (prefixcount == MAXPREFIXES) {
 175                                 warnx("memory for prefixes exceeded in line %d", linenum);
 176                                 continue;
 177                         }
 178                         lineptr[strlen(lineptr) - 1] = 0;
 179                         prefixtable[prefixcount].prefixname = dupstr(lineptr);
 180                         for (i = 0; i < prefixcount; i++)
 181                                 if (!strcmp(prefixtable[i].prefixname, lineptr)) {
 182                                         warnx("redefinition of prefix '%s' on line %d ignored",
 183                                             lineptr, linenum);
 184                                         continue;
 185                                 }
 186                         lineptr += len + 1;
 187                         lineptr += strspn(lineptr, " \n\t");
 188                         len = strcspn(lineptr, "\n\t");
 189                         if (len == 0) {
 190                                 warnx("unexpected end of prefix on line %d",
 191                                     linenum);
 192                                 continue;
 193                         }
 194                         lineptr[len] = 0;
 195                         prefixtable[prefixcount++].prefixval = dupstr(lineptr);
 196                 }
 197                 else {          /* it's not a prefix */
 198                         if (unitcount == MAXUNITS) {
 199                                 warnx("memory for units exceeded in line %d", 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("redefinition of unit '%s' on line %d ignored",
 206                                             lineptr, linenum);
 207                                         continue;
 208                                 }
 209                         lineptr += len + 1;
 210                         lineptr += strspn(lineptr, " \n\t");
 211                         if (!strlen(lineptr)) {
 212                                 warnx("unexpected end of unit on line %d",
 213                                     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 static void
 225 initializeunit(struct unittype * theunit)
 226 {
 227         theunit->numerator[0] = theunit->denominator[0] = NULL;
 228         theunit->factor = 1.0;
 229         theunit->offset = 0.0;
 230         theunit->quantity = 0;
 231 }
 232
 233
 234 static int
 235 addsubunit(char *product[], char *toadd)
 236 {
 237         char **ptr;
 238
 239         for (ptr = product; *ptr && *ptr != NULLUNIT; ptr++);
 240         if (ptr >= product + MAXSUBUNITS) {
 241                 warnx("memory overflow in unit reduction");
 242                 return 1;
 243         }
 244         if (!*ptr)
 245                 *(ptr + 1) = NULL;
 246         *ptr = dupstr(toadd);
 247         return 0;
 248 }
 249
 250
 251 static void
 252 showunit(struct unittype * theunit)
 253 {
 254         char **ptr;
 255         int printedslash;
 256         int counter = 1;
 257
 258         printf(numfmt, theunit->factor);
 259         if (theunit->offset)
 260                 printf("&%.8g", theunit->offset);
 261         for (ptr = theunit->numerator; *ptr; ptr++) {
 262                 if (ptr > theunit->numerator && **ptr &&
 263                     !strcmp(*ptr, *(ptr - 1)))
 264                         counter++;
 265                 else {
 266                         if (counter > 1)
 267                                 printf("%s%d", powerstring, counter);
 268                         if (**ptr)
 269                                 printf(" %s", *ptr);
 270                         counter = 1;
 271                 }
 272         }
 273         if (counter > 1)
 274                 printf("%s%d", powerstring, counter);
 275         counter = 1;
 276         printedslash = 0;
 277         for (ptr = theunit->denominator; *ptr; ptr++) {
 278                 if (ptr > theunit->denominator && **ptr &&
 279                     !strcmp(*ptr, *(ptr - 1)))
 280                         counter++;
 281                 else {
 282                         if (counter > 1)
 283                                 printf("%s%d", powerstring, counter);
 284                         if (**ptr) {
 285                                 if (!printedslash)
 286                                         printf(" /");
 287                                 printedslash = 1;
 288                                 printf(" %s", *ptr);
 289                         }
 290                         counter = 1;
 291                 }
 292         }
 293         if (counter > 1)
 294                 printf("%s%d", powerstring, counter);
 295         printf("\n");
 296 }
 297
 298
 299 void
 300 zeroerror(void)
 301 {
 302         warnx("unit reduces to zero");
 303 }
 304
 305 /*
 306    Adds the specified string to the unit.
 307    Flip is 0 for adding normally, 1 for adding reciprocal.
 308    Quantity is 1 if this is a quantity to be converted rather than a pure unit.
 309
 310    Returns 0 for successful addition, nonzero on error.
 311 */
 312
 313 static int
 314 addunit(struct unittype * theunit, const char *toadd, int flip, int quantity)
 315 {
 316         char *scratch, *savescr;
 317         char *item;
 318         char *divider, *slash, *offset;
 319         int doingtop;
 320
 321         if (!strlen(toadd))
 322                 return 1;
 323
 324         savescr = scratch = dupstr(toadd);
 325         for (slash = scratch + 1; *slash; slash++)
 326                 if (*slash == '-' &&
 327                     (tolower(*(slash - 1)) != 'e' ||
 328                     !strchr(".0123456789", *(slash + 1))))
 329                         *slash = ' ';
 330         slash = strchr(scratch, '/');
 331         if (slash)
 332                 *slash = 0;
 333         doingtop = 1;
 334         do {
 335                 item = strtok(scratch, " *\t\n/");
 336                 while (item) {
 337                         if (strchr("0123456789.", *item)) { /* item is a number */
 338                                 double num, offsetnum;
 339
 340                                 if (quantity)
 341                                         theunit->quantity = 1;
 342
 343                                 offset = strchr(item, '&');
 344                                 if (offset) {
 345                                         *offset = 0;
 346                                         offsetnum = atof(offset+1);
 347                                 } else
 348                                         offsetnum = 0.0;
 349
 350                                 divider = strchr(item, '|');
 351                                 if (divider) {
 352                                         *divider = 0;
 353                                         num = atof(item);
 354                                         if (!num) {
 355                                                 zeroerror();
 356                                                 free(savescr);
 357                                                 return 1;
 358                                         }
 359                                         if (doingtop ^ flip) {
 360                                                 theunit->factor *= num;
 361                                                 theunit->offset *= num;
 362                                         } else {
 363                                                 theunit->factor /= num;
 364                                                 theunit->offset /= num;
 365                                         }
 366                                         num = atof(divider + 1);
 367                                         if (!num) {
 368                                                 zeroerror();
 369                                                 free(savescr);
 370                                                 return 1;
 371                                         }
 372                                         if (doingtop ^ flip) {
 373                                                 theunit->factor /= num;
 374                                                 theunit->offset /= num;
 375                                         } else {
 376                                                 theunit->factor *= num;
 377                                                 theunit->offset *= num;
 378                                         }
 379                                 }
 380                                 else {
 381                                         num = atof(item);
 382                                         if (!num) {
 383                                                 zeroerror();
 384                                                 free(savescr);
 385                                                 return 1;
 386                                         }
 387                                         if (doingtop ^ flip) {
 388                                                 theunit->factor *= num;
 389                                                 theunit->offset *= num;
 390                                         } else {
 391                                                 theunit->factor /= num;
 392                                                 theunit->offset /= num;
 393                                         }
 394                                 }
 395                                 if (doingtop ^ flip)
 396                                         theunit->offset += offsetnum;
 397                         }
 398                         else {  /* item is not a number */
 399                                 int repeat = 1;
 400
 401                                 if (strchr("23456789",
 402                                     item[strlen(item) - 1])) {
 403                                         repeat = item[strlen(item) - 1] - '0';
 404                                         item[strlen(item) - 1] = 0;
 405                                 }
 406                                 for (; repeat; repeat--) {
 407                                         if (addsubunit(doingtop ^ flip ? theunit->numerator : theunit->denominator, item)) {
 408                                                 free(savescr);
 409                                                 return 1;
 410                                         }
 411                                 }
 412                         }
 413                         item = strtok(NULL, " *\t/\n");
 414                 }
 415                 doingtop--;
 416                 if (slash) {
 417                         scratch = slash + 1;
 418                 }
 419                 else
 420                         doingtop--;
 421         } while (doingtop >= 0);
 422         free(savescr);
 423         return 0;
 424 }
 425
 426
 427 static int
 428 compare(const void *item1, const void *item2)
 429 {
 430         return strcmp(*(const char * const *)item1, *(const char * const *)item2);
 431 }
 432
 433
 434 static void
 435 sortunit(struct unittype * theunit)
 436 {
 437         char **ptr;
 438         unsigned int count;
 439
 440         for (count = 0, ptr = theunit->numerator; *ptr; ptr++, count++);
 441         qsort(theunit->numerator, count, sizeof(char *), compare);
 442         for (count = 0, ptr = theunit->denominator; *ptr; ptr++, count++);
 443         qsort(theunit->denominator, count, sizeof(char *), compare);
 444 }
 445
 446
 447 void
 448 cancelunit(struct unittype * theunit)
 449 {
 450         char **den, **num;
 451         int comp;
 452
 453         den = theunit->denominator;
 454         num = theunit->numerator;
 455
 456         while (*num && *den) {
 457                 comp = strcmp(*den, *num);
 458                 if (!comp) {
 459 /*      if (*den!=NULLUNIT) free(*den);
 460       if (*num!=NULLUNIT) free(*num);*/
 461                         *den++ = NULLUNIT;
 462                         *num++ = NULLUNIT;
 463                 }
 464                 else if (comp < 0)
 465                         den++;
 466                 else
 467                         num++;
 468         }
 469 }
 470
 471
 472
 473
 474 /*
 475    Looks up the definition for the specified unit.
 476    Returns a pointer to the definition or a null pointer
 477    if the specified unit does not appear in the units table.
 478 */
 479
 480 static char buffer[100];        /* buffer for lookupunit answers with
 481                                    prefixes */
 482
 483 char *
 484 lookupunit(const char *unit)
 485 {
 486         int i;
 487         char *copy;
 488
 489         for (i = 0; i < unitcount; i++) {
 490                 if (!strcmp(unittable[i].uname, unit))
 491                         return unittable[i].uval;
 492         }
 493
 494         if (unit[strlen(unit) - 1] == '^') {
 495                 copy = dupstr(unit);
 496                 copy[strlen(copy) - 1] = 0;
 497                 for (i = 0; i < unitcount; i++) {
 498                         if (!strcmp(unittable[i].uname, copy)) {
 499                                 strlcpy(buffer, copy, sizeof(buffer));
 500                                 free(copy);
 501                                 return buffer;
 502                         }
 503                 }
 504                 free(copy);
 505         }
 506         if (unit[strlen(unit) - 1] == 's') {
 507                 copy = dupstr(unit);
 508                 copy[strlen(copy) - 1] = 0;
 509                 for (i = 0; i < unitcount; i++) {
 510                         if (!strcmp(unittable[i].uname, copy)) {
 511                                 strlcpy(buffer, copy, sizeof(buffer));
 512                                 free(copy);
 513                                 return buffer;
 514                         }
 515                 }
 516                 if (copy[strlen(copy) - 1] == 'e') {
 517                         copy[strlen(copy) - 1] = 0;
 518                         for (i = 0; i < unitcount; i++) {
 519                                 if (!strcmp(unittable[i].uname, copy)) {
 520                                         strlcpy(buffer, copy, sizeof(buffer));
 521                                         free(copy);
 522                                         return buffer;
 523                                 }
 524                         }
 525                 }
 526                 free(copy);
 527         }
 528         for (i = 0; i < prefixcount; i++) {
 529                 size_t len = strlen(prefixtable[i].prefixname);
 530                 if (!strncmp(prefixtable[i].prefixname, unit, len)) {
 531                         if (!strlen(unit + len) || lookupunit(unit + len)) {
 532                                 snprintf(buffer, sizeof(buffer), "%s %s",
 533                                     prefixtable[i].prefixval, unit + len);
 534                                 return buffer;
 535                         }
 536                 }
 537         }
 538         return 0;
 539 }
 540
 541
 542
 543 /*
 544    reduces a product of symbolic units to primitive units.
 545    The three low bits are used to return flags:
 546
 547      bit 0 (1) set on if reductions were performed without error.
 548      bit 1 (2) set on if no reductions are performed.
 549      bit 2 (4) set on if an unknown unit is discovered.
 550 */
 551
 552
 553 #define ERROR 4
 554
 555 static int
 556 reduceproduct(struct unittype * theunit, int flip)
 557 {
 558
 559         char *toadd;
 560         char **product;
 561         int didsomething = 2;
 562
 563         if (flip)
 564                 product = theunit->denominator;
 565         else
 566                 product = theunit->numerator;
 567
 568         for (; *product; product++) {
 569
 570                 for (;;) {
 571                         if (!strlen(*product))
 572                                 break;
 573                         toadd = lookupunit(*product);
 574                         if (!toadd) {
 575                                 printf("unknown unit '%s'\n", *product);
 576                                 return ERROR;
 577                         }
 578                         if (strchr(toadd, PRIMITIVECHAR))
 579                                 break;
 580                         didsomething = 1;
 581                         if (*product != NULLUNIT) {
 582                                 free(*product);
 583                                 *product = NULLUNIT;
 584                         }
 585                         if (addunit(theunit, toadd, flip, 0))
 586                                 return ERROR;
 587                 }
 588         }
 589         return didsomething;
 590 }
 591
 592
 593 /*
 594    Reduces numerator and denominator of the specified unit.
 595    Returns 0 on success, or 1 on unknown unit error.
 596 */
 597
 598 static int
 599 reduceunit(struct unittype * theunit)
 600 {
 601         int ret;
 602
 603         ret = 1;
 604         while (ret & 1) {
 605                 ret = reduceproduct(theunit, 0) | reduceproduct(theunit, 1);
 606                 if (ret & 4)
 607                         return 1;
 608         }
 609         return 0;
 610 }
 611
 612
 613 static int
 614 compareproducts(char **one, char **two)
 615 {
 616         while (*one || *two) {
 617                 if (!*one && *two != NULLUNIT)
 618                         return 1;
 619                 if (!*two && *one != NULLUNIT)
 620                         return 1;
 621                 if (*one == NULLUNIT)
 622                         one++;
 623                 else if (*two == NULLUNIT)
 624                         two++;
 625                 else if (strcmp(*one, *two))
 626                         return 1;
 627                 else {
 628                         one++;
 629                         two++;
 630                 }
 631         }
 632         return 0;
 633 }
 634
 635
 636 /* Return zero if units are compatible, nonzero otherwise */
 637
 638 static int
 639 compareunits(struct unittype * first, struct unittype * second)
 640 {
 641         return
 642         compareproducts(first->numerator, second->numerator) ||
 643         compareproducts(first->denominator, second->denominator);
 644 }
 645
 646
 647 static int
 648 completereduce(struct unittype * unit)
 649 {
 650         if (reduceunit(unit))
 651                 return 1;
 652         sortunit(unit);
 653         cancelunit(unit);
 654         return 0;
 655 }
 656
 657 static void
 658 showanswer(struct unittype * have, struct unittype * want)
 659 {
 660         double ans;
 661         char* oformat;
 662
 663         if (compareunits(have, want)) {
 664                 printf("conformability error\n");
 665                 if (verbose)
 666                         printf("\t%s = ", havestr);
 667                 else if (!terse)
 668                         printf("\t");
 669                 showunit(have);
 670                 if (!terse) {
 671                         if (verbose)
 672                                 printf("\t%s = ", wantstr);
 673                         else
 674                                 printf("\t");
 675                         showunit(want);
 676                 }
 677         }
 678         else if (have->offset != want->offset) {
 679                 if (want->quantity)
 680                         printf("WARNING: conversion of non-proportional quantities.\n");
 681                 if (have->quantity) {
 682                         asprintf(&oformat, "\t%s\n", outputformat);
 683                         printf(oformat,
 684                             (have->factor + have->offset-want->offset)/want->factor);
 685                         free(oformat);
 686                 }
 687                 else {
 688                         asprintf(&oformat, "\t (-> x*%sg %sg)\n\t (<- y*%sg %sg)\n",
 689                             outputformat, outputformat, outputformat, outputformat);
 690                         printf(oformat,
 691                             have->factor / want->factor,
 692                             (have->offset-want->offset)/want->factor,
 693                             want->factor / have->factor,
 694                             (want->offset - have->offset)/have->factor);
 695                 }
 696         }
 697         else {
 698                 ans = have->factor / want->factor;
 699
 700                 if (verbose) {
 701                         printf("\t%s = ", havestr);
 702                         printf(outputformat, ans);
 703                         printf(" * %s", wantstr);
 704                         printf("\n");
 705                 }
 706                 else if (terse) {
 707                         printf(outputformat, ans);
 708                         printf("\n");
 709                 }
 710                 else {
 711                         printf("\t* ");
 712                         printf(outputformat, ans);
 713                         printf("\n");
 714                 }
 715
 716                 if (verbose) {
 717                         printf("\t%s = (1 / ", havestr);
 718                         printf(outputformat, 1/ans);
 719                         printf(") * %s\n", wantstr);
 720                 }
 721                 else if (!terse) {
 722                         printf("\t/ ");
 723                         printf(outputformat, 1/ans);
 724                         printf("\n");
 725                 }
 726         }
 727 }
 728
 729
 730 static void __dead2
 731 usage(void)
 732 {
 733         fprintf(stderr,
 734             "usage: units [-ehqtUVv] [-f unitsfile] [-o format] [from to]\n");
 735         exit(3);
 736 }
 737
 738 static struct option longopts[] = {
 739         {"exponential", no_argument, NULL, 'e'},
 740         {"file", required_argument, NULL, 'f'},
 741         {"history", required_argument, NULL, 'H'},
 742         {"help", no_argument, NULL, 'h'},
 743         {"output-format", required_argument, NULL, 'o'},
 744         {"quiet", no_argument, NULL, 'q'},
 745         {"terse", no_argument, NULL, 't'},
 746         {"unitsfile", no_argument, NULL, 'U'},
 747         {"version", no_argument, NULL, 'V'},
 748         {"verbose", no_argument, NULL, 'v'},
 749         { 0, 0, 0, 0 }
 750 };
 751
 752
 753 int
 754 main(int argc, char **argv)
 755 {
 756
 757         struct unittype have, want;
 758         int optchar;
 759         bool quiet;
 760         bool readfile;
 761         bool quit;
 762         History *inhistory;
 763         EditLine *el;
 764         HistEvent ev;
 765         int inputsz;
 766         char const * history_file;
 767
 768         quiet = false;
 769         readfile = false;
 770         history_file = NULL;
 771         outputformat = numfmt;
 772         quit = false;
 773         while ((optchar = getopt_long(argc, argv, "+ehf:o:qtvH:UV", longopts, NULL)) != -1) {
 774                 switch (optchar) {
 775                 case 'e':
 776                         outputformat = "%6e";
 777                         break;
 778                 case 'f':
 779                         readfile = true;
 780                         if (strlen(optarg) == 0)
 781                                 readunits(NULL);
 782                         else
 783                                 readunits(optarg);
 784                         break;
 785                 case 'H':
 786                         history_file = optarg;
 787                         break;
 788                 case 'q':
 789                         quiet = true;
 790                         break;
 791                 case 't':
 792                         terse = true;
 793                         break;
 794                 case 'o':
 795                         outputformat = optarg;
 796                         break;
 797                 case 'v':
 798                         verbose = true;
 799                         break;
 800                 case 'V':
 801                         fprintf(stderr, "FreeBSD units\n");
 802                         /* FALLTHROUGH */
 803                 case 'U':
 804                         if (access(UNITSFILE, F_OK) == 0)
 805                                 printf("%s\n", UNITSFILE);
 806                         else
 807                                 printf("Units data file not found");
 808                         exit(0);
 809                 case 'h':
 810                         /* FALLTHROUGH */
 811
 812                 default:
 813                         usage();
 814                 }
 815         }
 816
 817         if (!readfile)
 818                 readunits(NULL);
 819
 820         if (optind == argc - 2) {
 821                 if (caph_enter() < 0)
 822                         err(1, "unable to enter capability mode");
 823
 824                 havestr = argv[optind];
 825                 wantstr = argv[optind + 1];
 826                 initializeunit(&have);
 827                 addunit(&have, havestr, 0, 1);
 828                 completereduce(&have);
 829                 initializeunit(&want);
 830                 addunit(&want, wantstr, 0, 1);
 831                 completereduce(&want);
 832                 showanswer(&have, &want);
 833         } else {
 834                 inhistory = history_init();
 835                 el = el_init(argv[0], stdin, stdout, stderr);
 836                 el_set(el, EL_PROMPT, &prompt);
 837                 el_set(el, EL_EDITOR, "emacs");
 838                 el_set(el, EL_SIGNAL, 1);
 839                 el_set(el, EL_HIST, history, inhistory);
 840                 el_source(el, NULL);
 841                 history(inhistory, &ev, H_SETSIZE, 800);
 842                 if (inhistory == 0)
 843                         err(1, "Could not initialize history");
 844
 845                 if (caph_enter() < 0)
 846                         err(1, "unable to enter capability mode");
 847
 848                 if (!quiet)
 849                         printf("%d units, %d prefixes\n", unitcount,
 850                             prefixcount);
 851                 while (!quit) {
 852                         do {
 853                                 initializeunit(&have);
 854                                 if (!quiet)
 855                                         promptstr = "You have: ";
 856                                 havestr = el_gets(el, &inputsz);
 857                                 if (havestr == NULL) {
 858                                         quit = true;
 859                                         break;
 860                                 }
 861                                 if (inputsz > 0)
 862                                         history(inhistory, &ev, H_ENTER,
 863                                         havestr);
 864                         } while (addunit(&have, havestr, 0, 1) ||
 865                             completereduce(&have));
 866                         if (quit) {
 867                                 break;
 868                         }
 869                         do {
 870                                 initializeunit(&want);
 871                                 if (!quiet)
 872                                         promptstr = "You want: ";
 873                                 wantstr = el_gets(el, &inputsz);
 874                                 if (wantstr == NULL) {
 875                                         quit = true;
 876                                         break;
 877                                 }
 878                                 if (inputsz > 0)
 879                                         history(inhistory, &ev, H_ENTER,
 880                                         wantstr);
 881                         } while (addunit(&want, wantstr, 0, 1) ||
 882                             completereduce(&want));
 883                         if (quit) {
 884                                 break;
 885                         }
 886                         showanswer(&have, &want);
 887                 }
 888
 889                 history_end(inhistory);
 890                 el_end(el);
 891         }
 892
 893         return (0);
 894 }