2 * units.c Copyright (c) 1993 by Adrian Mariano (adrian@cam.cornell.edu)
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. The name of the author may not be used to endorse or promote products
10 * derived from this software without specific prior written permission.
11 * Disclaimer: This software is provided by the author "as is". The author
12 * shall not be liable for any damages caused in any way by this software.
14 * I would appreciate (though I do not require) receiving a copy of any
15 * improvements you might make to this program.
19 static const char rcsid[] =
34 #include <sys/capsicum.h>
36 #include "pathnames.h"
39 #define UNITSFILE _PATH_UNITSLIB
43 #define MAXPREFIXES 100
45 #define MAXSUBUNITS 500
47 #define PRIMITIVECHAR '!'
49 static const char *powerstring = "^";
54 } unittable[MAXUNITS];
57 char *numerator[MAXSUBUNITS];
58 char *denominator[MAXSUBUNITS];
67 } prefixtable[MAXPREFIXES];
70 static char NULLUNIT[] = "";
75 static int prefixcount;
76 static bool verbose = false;
77 static bool terse = false;
78 static const char * outputformat;
79 static const char * havestr;
80 static const char * wantstr;
82 static int addsubunit(char *product[], char *toadd);
83 static int addunit(struct unittype *theunit, const char *toadd, int flip, int quantity);
84 static void cancelunit(struct unittype * theunit);
85 static int compare(const void *item1, const void *item2);
86 static int compareproducts(char **one, char **two);
87 static int compareunits(struct unittype * first, struct unittype * second);
88 static int completereduce(struct unittype * unit);
89 static char *dupstr(const char *str);
90 static void initializeunit(struct unittype * theunit);
91 static char *lookupunit(const char *unit);
92 static void readunits(const char *userfile);
93 static int reduceproduct(struct unittype * theunit, int flip);
94 static int reduceunit(struct unittype * theunit);
95 static void showanswer(struct unittype * have, struct unittype * want);
96 static void showunit(struct unittype * theunit);
97 static void sortunit(struct unittype * theunit);
98 static void usage(void);
99 static void zeroerror(void);
101 static const char* promptstr = "";
103 static const char * prompt(EditLine *e __unused) {
108 dupstr(const char *str)
120 readunits(const char *userfile)
123 char line[512], *lineptr;
125 cap_rights_t unitfilerights;
131 unitfile = fopen(userfile, "rt");
133 errx(1, "unable to open units file '%s'", userfile);
136 unitfile = fopen(UNITSFILE, "rt");
141 env = getenv("PATH");
143 direc = strtok(env, SEPARATOR);
145 snprintf(filename, sizeof(filename),
146 "%s/%s", direc, UNITSFILE);
147 unitfile = fopen(filename, "rt");
150 direc = strtok(NULL, SEPARATOR);
154 errx(1, "can't find units file '%s'", UNITSFILE);
157 cap_rights_init(&unitfilerights, CAP_READ, CAP_FSTAT);
158 if (cap_rights_limit(fileno(unitfile), &unitfilerights) < 0
160 err(1, "cap_rights_limit() failed");
161 while (!feof(unitfile)) {
162 if (!fgets(line, sizeof(line), unitfile))
166 if (*lineptr == '/' || *lineptr == '#')
168 lineptr += strspn(lineptr, " \n\t");
169 len = strcspn(lineptr, " \n\t");
171 if (!strlen(lineptr))
173 if (lineptr[strlen(lineptr) - 1] == '-') { /* it's a prefix */
174 if (prefixcount == MAXPREFIXES) {
175 warnx("memory for prefixes exceeded in line %d", linenum);
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",
187 lineptr += strspn(lineptr, " \n\t");
188 len = strcspn(lineptr, "\n\t");
190 warnx("unexpected end of prefix on line %d",
195 prefixtable[prefixcount++].prefixval = dupstr(lineptr);
197 else { /* it's not a prefix */
198 if (unitcount == MAXUNITS) {
199 warnx("memory for units exceeded in line %d", linenum);
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",
210 lineptr += strspn(lineptr, " \n\t");
211 if (!strlen(lineptr)) {
212 warnx("unexpected end of unit on line %d",
216 len = strcspn(lineptr, "\n\t");
218 unittable[unitcount++].uval = dupstr(lineptr);
225 initializeunit(struct unittype * theunit)
227 theunit->numerator[0] = theunit->denominator[0] = NULL;
228 theunit->factor = 1.0;
229 theunit->offset = 0.0;
230 theunit->quantity = 0;
235 addsubunit(char *product[], char *toadd)
239 for (ptr = product; *ptr && *ptr != NULLUNIT; ptr++);
240 if (ptr >= product + MAXSUBUNITS) {
241 warnx("memory overflow in unit reduction");
246 *ptr = dupstr(toadd);
252 showunit(struct unittype * theunit)
258 printf("%.8g", theunit->factor);
260 printf("&%.8g", theunit->offset);
261 for (ptr = theunit->numerator; *ptr; ptr++) {
262 if (ptr > theunit->numerator && **ptr &&
263 !strcmp(*ptr, *(ptr - 1)))
267 printf("%s%d", powerstring, counter);
274 printf("%s%d", powerstring, counter);
277 for (ptr = theunit->denominator; *ptr; ptr++) {
278 if (ptr > theunit->denominator && **ptr &&
279 !strcmp(*ptr, *(ptr - 1)))
283 printf("%s%d", powerstring, counter);
294 printf("%s%d", powerstring, counter);
302 warnx("unit reduces to zero");
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.
310 Returns 0 for successful addition, nonzero on error.
314 addunit(struct unittype * theunit, const char *toadd, int flip, int quantity)
316 char *scratch, *savescr;
318 char *divider, *slash, *offset;
324 savescr = scratch = dupstr(toadd);
325 for (slash = scratch + 1; *slash; slash++)
327 (tolower(*(slash - 1)) != 'e' ||
328 !strchr(".0123456789", *(slash + 1))))
330 slash = strchr(scratch, '/');
335 item = strtok(scratch, " *\t\n/");
337 if (strchr("0123456789.", *item)) { /* item is a number */
338 double num, offsetnum;
341 theunit->quantity = 1;
343 offset = strchr(item, '&');
346 offsetnum = atof(offset+1);
350 divider = strchr(item, '|');
358 if (doingtop ^ flip) {
359 theunit->factor *= num;
360 theunit->offset *= num;
362 theunit->factor /= num;
363 theunit->offset /= num;
365 num = atof(divider + 1);
370 if (doingtop ^ flip) {
371 theunit->factor /= num;
372 theunit->offset /= num;
374 theunit->factor *= num;
375 theunit->offset *= num;
384 if (doingtop ^ flip) {
385 theunit->factor *= num;
386 theunit->offset *= num;
388 theunit->factor /= num;
389 theunit->offset /= num;
393 theunit->offset += offsetnum;
395 else { /* item is not a number */
398 if (strchr("23456789",
399 item[strlen(item) - 1])) {
400 repeat = item[strlen(item) - 1] - '0';
401 item[strlen(item) - 1] = 0;
403 for (; repeat; repeat--)
404 if (addsubunit(doingtop ^ flip ? theunit->numerator : theunit->denominator, item))
407 item = strtok(NULL, " *\t/\n");
415 } while (doingtop >= 0);
422 compare(const void *item1, const void *item2)
424 return strcmp(*(const char * const *)item1, *(const char * const *)item2);
429 sortunit(struct unittype * theunit)
434 for (count = 0, ptr = theunit->numerator; *ptr; ptr++, count++);
435 qsort(theunit->numerator, count, sizeof(char *), compare);
436 for (count = 0, ptr = theunit->denominator; *ptr; ptr++, count++);
437 qsort(theunit->denominator, count, sizeof(char *), compare);
442 cancelunit(struct unittype * theunit)
447 den = theunit->denominator;
448 num = theunit->numerator;
450 while (*num && *den) {
451 comp = strcmp(*den, *num);
453 /* if (*den!=NULLUNIT) free(*den);
454 if (*num!=NULLUNIT) free(*num);*/
469 Looks up the definition for the specified unit.
470 Returns a pointer to the definition or a null pointer
471 if the specified unit does not appear in the units table.
474 static char buffer[100]; /* buffer for lookupunit answers with
478 lookupunit(const char *unit)
483 for (i = 0; i < unitcount; i++) {
484 if (!strcmp(unittable[i].uname, unit))
485 return unittable[i].uval;
488 if (unit[strlen(unit) - 1] == '^') {
490 copy[strlen(copy) - 1] = 0;
491 for (i = 0; i < unitcount; i++) {
492 if (!strcmp(unittable[i].uname, copy)) {
493 strlcpy(buffer, copy, sizeof(buffer));
500 if (unit[strlen(unit) - 1] == 's') {
502 copy[strlen(copy) - 1] = 0;
503 for (i = 0; i < unitcount; i++) {
504 if (!strcmp(unittable[i].uname, copy)) {
505 strlcpy(buffer, copy, sizeof(buffer));
510 if (copy[strlen(copy) - 1] == 'e') {
511 copy[strlen(copy) - 1] = 0;
512 for (i = 0; i < unitcount; i++) {
513 if (!strcmp(unittable[i].uname, copy)) {
514 strlcpy(buffer, copy, sizeof(buffer));
522 for (i = 0; i < prefixcount; i++) {
523 size_t len = strlen(prefixtable[i].prefixname);
524 if (!strncmp(prefixtable[i].prefixname, unit, len)) {
525 if (!strlen(unit + len) || lookupunit(unit + len)) {
526 snprintf(buffer, sizeof(buffer), "%s %s",
527 prefixtable[i].prefixval, unit + len);
538 reduces a product of symbolic units to primitive units.
539 The three low bits are used to return flags:
541 bit 0 (1) set on if reductions were performed without error.
542 bit 1 (2) set on if no reductions are performed.
543 bit 2 (4) set on if an unknown unit is discovered.
550 reduceproduct(struct unittype * theunit, int flip)
555 int didsomething = 2;
558 product = theunit->denominator;
560 product = theunit->numerator;
562 for (; *product; product++) {
565 if (!strlen(*product))
567 toadd = lookupunit(*product);
569 printf("unknown unit '%s'\n", *product);
572 if (strchr(toadd, PRIMITIVECHAR))
575 if (*product != NULLUNIT) {
579 if (addunit(theunit, toadd, flip, 0))
588 Reduces numerator and denominator of the specified unit.
589 Returns 0 on success, or 1 on unknown unit error.
593 reduceunit(struct unittype * theunit)
599 ret = reduceproduct(theunit, 0) | reduceproduct(theunit, 1);
608 compareproducts(char **one, char **two)
610 while (*one || *two) {
611 if (!*one && *two != NULLUNIT)
613 if (!*two && *one != NULLUNIT)
615 if (*one == NULLUNIT)
617 else if (*two == NULLUNIT)
619 else if (strcmp(*one, *two))
628 /* Return zero if units are compatible, nonzero otherwise */
631 compareunits(struct unittype * first, struct unittype * second)
634 compareproducts(first->numerator, second->numerator) ||
635 compareproducts(first->denominator, second->denominator);
640 completereduce(struct unittype * unit)
642 if (reduceunit(unit))
650 showanswer(struct unittype * have, struct unittype * want)
655 if (compareunits(have, want)) {
656 printf("conformability error\n");
658 printf("\t%s = ", havestr);
664 printf("\t%s = ", wantstr);
670 else if (have->offset != want->offset) {
672 printf("WARNING: conversion of non-proportional quantities.\n");
673 if (have->quantity) {
674 asprintf(&oformat, "\t%s\n", outputformat);
676 (have->factor + have->offset-want->offset)/want->factor);
680 asprintf(&oformat, "\t (-> x*%sg %sg)\n\t (<- y*%sg %sg)\n",
681 outputformat, outputformat, outputformat, outputformat);
683 have->factor / want->factor,
684 (have->offset-want->offset)/want->factor,
685 want->factor / have->factor,
686 (want->offset - have->offset)/have->factor);
690 ans = have->factor / want->factor;
693 printf("\t%s = ", havestr);
694 printf(outputformat, ans);
695 printf(" * %s", wantstr);
699 printf(outputformat, ans);
704 printf(outputformat, ans);
709 printf("\t%s = (1 / ", havestr);
710 printf(outputformat, 1/ans);
711 printf(") * %s\n", wantstr);
715 printf(outputformat, 1/ans);
726 "usage: units [-f unitsfile] [-UVq] [from-unit to-unit]\n");
730 static struct option longopts[] = {
731 {"help", no_argument, NULL, 'h'},
732 {"exponential", no_argument, NULL, 'e'},
733 {"file", required_argument, NULL, 'f'},
734 {"output-format", required_argument, NULL, 'o'},
735 {"quiet", no_argument, NULL, 'q'},
736 {"terse", no_argument, NULL, 't'},
737 {"unitsfile", no_argument, NULL, 'U'},
738 {"verbose", no_argument, NULL, 'v'},
739 {"version", no_argument, NULL, 'V'},
745 main(int argc, char **argv)
748 struct unittype have, want;
759 outputformat = "%.8g";
760 while ((optchar = getopt_long(argc, argv, "+ehf:oqtvUV", longopts, NULL)) != -1) {
763 outputformat = "%6e";
767 if (strlen(optarg) == 0)
779 outputformat = optarg;
785 fprintf(stderr, "FreeBSD units\n");
788 if (access(UNITSFILE, F_OK) == 0)
789 printf("%s\n", UNITSFILE);
791 printf("Units data file not found");
805 inhistory = history_init();
806 el = el_init(argv[0], stdin, stdout, stderr);
807 el_set(el, EL_PROMPT, &prompt);
808 el_set(el, EL_EDITOR, "emacs");
809 el_set(el, EL_SIGNAL, 1);
810 el_set(el, EL_HIST, history, inhistory);
812 history(inhistory, &ev, H_SETSIZE, 800);
814 err(1, "Could not initialize history");
816 if (cap_enter() < 0 && errno != ENOSYS)
817 err(1, "unable to enter capability mode");
819 if (optind == argc - 2) {
820 havestr = argv[optind];
821 wantstr = argv[optind + 1];
822 initializeunit(&have);
823 addunit(&have, havestr, 0, 1);
824 completereduce(&have);
825 initializeunit(&want);
826 addunit(&want, wantstr, 0, 1);
827 completereduce(&want);
828 showanswer(&have, &want);
832 printf("%d units, %d prefixes\n", unitcount,
836 initializeunit(&have);
838 promptstr = "You have: ";
839 havestr = el_gets(el, &inputsz);
843 history(inhistory, &ev, H_ENTER,
845 } while (addunit(&have, havestr, 0, 1) ||
846 completereduce(&have));
848 initializeunit(&want);
850 promptstr = "You want: ";
851 wantstr = el_gets(el, &inputsz);
855 history(inhistory, &ev, H_ENTER,
857 } while (addunit(&want, wantstr, 0, 1) ||
858 completereduce(&want));
859 showanswer(&have, &want);
863 history_end(inhistory);