freebsd-dev/usr.bin/units/units.c
Eitan Adler 6d12a83408 units(1): make -V print version instead of -v
The units program is likely little used.  It is even less likely that a script
will want the units program to print out its version number by passing -v.

GNU units uses -V for version and -v for verbosity.

Increase compatibility between these two versions (written by the same author)
by switching our flag as well.

Take this opportunity to remove bogus information about the version number and
just call it 'FreeBSD units'.

Discussed with:	cperciva, rwatson
2014-04-07 02:31:10 +00:00

756 lines
16 KiB
C

/*
* units.c Copyright (c) 1993 by Adrian Mariano (adrian@cam.cornell.edu)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
* Disclaimer: This software is provided by the author "as is". The author
* shall not be liable for any damages caused in any way by this software.
*
* I would appreciate (though I do not require) receiving a copy of any
* improvements you might make to this program.
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/capsicum.h>
#include "pathnames.h"
#ifndef UNITSFILE
#define UNITSFILE _PATH_UNITSLIB
#endif
#define MAXUNITS 1000
#define MAXPREFIXES 100
#define MAXSUBUNITS 500
#define PRIMITIVECHAR '!'
static const char *powerstring = "^";
static struct {
char *uname;
char *uval;
} unittable[MAXUNITS];
struct unittype {
char *numerator[MAXSUBUNITS];
char *denominator[MAXSUBUNITS];
double factor;
double offset;
int quantity;
};
static struct {
char *prefixname;
char *prefixval;
} prefixtable[MAXPREFIXES];
static char NULLUNIT[] = "";
#ifdef MSDOS
#define SEPARATOR ";"
#else
#define SEPARATOR ":"
#endif
static int unitcount;
static int prefixcount;
char *dupstr(const char *str);
void readunits(const char *userfile);
void initializeunit(struct unittype * theunit);
int addsubunit(char *product[], char *toadd);
void showunit(struct unittype * theunit);
void zeroerror(void);
int addunit(struct unittype *theunit, char *toadd, int flip, int quantity);
int compare(const void *item1, const void *item2);
void sortunit(struct unittype * theunit);
void cancelunit(struct unittype * theunit);
char *lookupunit(const char *unit);
int reduceproduct(struct unittype * theunit, int flip);
int reduceunit(struct unittype * theunit);
int compareproducts(char **one, char **two);
int compareunits(struct unittype * first, struct unittype * second);
int completereduce(struct unittype * unit);
void showanswer(struct unittype * have, struct unittype * want);
void usage(void);
char *
dupstr(const char *str)
{
char *ret;
ret = malloc(strlen(str) + 1);
if (!ret)
errx(3, "memory allocation error");
strcpy(ret, str);
return (ret);
}
void
readunits(const char *userfile)
{
FILE *unitfile;
char line[512], *lineptr;
int len, linenum, i;
cap_rights_t unitfilerights;
unitcount = 0;
linenum = 0;
if (userfile) {
unitfile = fopen(userfile, "rt");
if (!unitfile)
errx(1, "unable to open units file '%s'", userfile);
}
else {
unitfile = fopen(UNITSFILE, "rt");
if (!unitfile) {
char *direc, *env;
char filename[1000];
env = getenv("PATH");
if (env) {
direc = strtok(env, SEPARATOR);
while (direc) {
snprintf(filename, sizeof(filename),
"%s/%s", direc, UNITSFILE);
unitfile = fopen(filename, "rt");
if (unitfile)
break;
direc = strtok(NULL, SEPARATOR);
}
}
if (!unitfile)
errx(1, "can't find units file '%s'", UNITSFILE);
}
}
if (cap_enter() < 0 && errno != ENOSYS)
err(1, "unable to enter capability mode");
cap_rights_init(&unitfilerights, CAP_READ, CAP_FSTAT);
if (cap_rights_limit(fileno(unitfile), &unitfilerights) < 0
&& errno != ENOSYS)
err(1, "cap_rights_limit() failed");
while (!feof(unitfile)) {
if (!fgets(line, sizeof(line), unitfile))
break;
linenum++;
lineptr = line;
if (*lineptr == '/')
continue;
lineptr += strspn(lineptr, " \n\t");
len = strcspn(lineptr, " \n\t");
lineptr[len] = 0;
if (!strlen(lineptr))
continue;
if (lineptr[strlen(lineptr) - 1] == '-') { /* it's a prefix */
if (prefixcount == MAXPREFIXES) {
warnx("memory for prefixes exceeded in line %d", linenum);
continue;
}
lineptr[strlen(lineptr) - 1] = 0;
prefixtable[prefixcount].prefixname = dupstr(lineptr);
for (i = 0; i < prefixcount; i++)
if (!strcmp(prefixtable[i].prefixname, lineptr)) {
warnx("redefinition of prefix '%s' on line %d ignored",
lineptr, linenum);
continue;
}
lineptr += len + 1;
lineptr += strspn(lineptr, " \n\t");
len = strcspn(lineptr, "\n\t");
if (len == 0) {
warnx("unexpected end of prefix on line %d",
linenum);
continue;
}
lineptr[len] = 0;
prefixtable[prefixcount++].prefixval = dupstr(lineptr);
}
else { /* it's not a prefix */
if (unitcount == MAXUNITS) {
warnx("memory for units exceeded in line %d", linenum);
continue;
}
unittable[unitcount].uname = dupstr(lineptr);
for (i = 0; i < unitcount; i++)
if (!strcmp(unittable[i].uname, lineptr)) {
warnx("redefinition of unit '%s' on line %d ignored",
lineptr, linenum);
continue;
}
lineptr += len + 1;
lineptr += strspn(lineptr, " \n\t");
if (!strlen(lineptr)) {
warnx("unexpected end of unit on line %d",
linenum);
continue;
}
len = strcspn(lineptr, "\n\t");
lineptr[len] = 0;
unittable[unitcount++].uval = dupstr(lineptr);
}
}
fclose(unitfile);
}
void
initializeunit(struct unittype * theunit)
{
theunit->numerator[0] = theunit->denominator[0] = NULL;
theunit->factor = 1.0;
theunit->offset = 0.0;
theunit->quantity = 0;
}
int
addsubunit(char *product[], char *toadd)
{
char **ptr;
for (ptr = product; *ptr && *ptr != NULLUNIT; ptr++);
if (ptr >= product + MAXSUBUNITS) {
warnx("memory overflow in unit reduction");
return 1;
}
if (!*ptr)
*(ptr + 1) = 0;
*ptr = dupstr(toadd);
return 0;
}
void
showunit(struct unittype * theunit)
{
char **ptr;
int printedslash;
int counter = 1;
printf("\t%.8g", theunit->factor);
if (theunit->offset)
printf("&%.8g", theunit->offset);
for (ptr = theunit->numerator; *ptr; ptr++) {
if (ptr > theunit->numerator && **ptr &&
!strcmp(*ptr, *(ptr - 1)))
counter++;
else {
if (counter > 1)
printf("%s%d", powerstring, counter);
if (**ptr)
printf(" %s", *ptr);
counter = 1;
}
}
if (counter > 1)
printf("%s%d", powerstring, counter);
counter = 1;
printedslash = 0;
for (ptr = theunit->denominator; *ptr; ptr++) {
if (ptr > theunit->denominator && **ptr &&
!strcmp(*ptr, *(ptr - 1)))
counter++;
else {
if (counter > 1)
printf("%s%d", powerstring, counter);
if (**ptr) {
if (!printedslash)
printf(" /");
printedslash = 1;
printf(" %s", *ptr);
}
counter = 1;
}
}
if (counter > 1)
printf("%s%d", powerstring, counter);
printf("\n");
}
void
zeroerror(void)
{
warnx("unit reduces to zero");
}
/*
Adds the specified string to the unit.
Flip is 0 for adding normally, 1 for adding reciprocal.
Quantity is 1 if this is a quantity to be converted rather than a pure unit.
Returns 0 for successful addition, nonzero on error.
*/
int
addunit(struct unittype * theunit, char *toadd, int flip, int quantity)
{
char *scratch, *savescr;
char *item;
char *divider, *slash, *offset;
int doingtop;
if (!strlen(toadd))
return 1;
savescr = scratch = dupstr(toadd);
for (slash = scratch + 1; *slash; slash++)
if (*slash == '-' &&
(tolower(*(slash - 1)) != 'e' ||
!strchr(".0123456789", *(slash + 1))))
*slash = ' ';
slash = strchr(scratch, '/');
if (slash)
*slash = 0;
doingtop = 1;
do {
item = strtok(scratch, " *\t\n/");
while (item) {
if (strchr("0123456789.", *item)) { /* item is a number */
double num, offsetnum;
if (quantity)
theunit->quantity = 1;
offset = strchr(item, '&');
if (offset) {
*offset = 0;
offsetnum = atof(offset+1);
} else
offsetnum = 0.0;
divider = strchr(item, '|');
if (divider) {
*divider = 0;
num = atof(item);
if (!num) {
zeroerror();
return 1;
}
if (doingtop ^ flip) {
theunit->factor *= num;
theunit->offset *= num;
} else {
theunit->factor /= num;
theunit->offset /= num;
}
num = atof(divider + 1);
if (!num) {
zeroerror();
return 1;
}
if (doingtop ^ flip) {
theunit->factor /= num;
theunit->offset /= num;
} else {
theunit->factor *= num;
theunit->offset *= num;
}
}
else {
num = atof(item);
if (!num) {
zeroerror();
return 1;
}
if (doingtop ^ flip) {
theunit->factor *= num;
theunit->offset *= num;
} else {
theunit->factor /= num;
theunit->offset /= num;
}
}
if (doingtop ^ flip)
theunit->offset += offsetnum;
}
else { /* item is not a number */
int repeat = 1;
if (strchr("23456789",
item[strlen(item) - 1])) {
repeat = item[strlen(item) - 1] - '0';
item[strlen(item) - 1] = 0;
}
for (; repeat; repeat--)
if (addsubunit(doingtop ^ flip ? theunit->numerator : theunit->denominator, item))
return 1;
}
item = strtok(NULL, " *\t/\n");
}
doingtop--;
if (slash) {
scratch = slash + 1;
}
else
doingtop--;
} while (doingtop >= 0);
free(savescr);
return 0;
}
int
compare(const void *item1, const void *item2)
{
return strcmp(*(const char * const *)item1, *(const char * const *)item2);
}
void
sortunit(struct unittype * theunit)
{
char **ptr;
unsigned int count;
for (count = 0, ptr = theunit->numerator; *ptr; ptr++, count++);
qsort(theunit->numerator, count, sizeof(char *), compare);
for (count = 0, ptr = theunit->denominator; *ptr; ptr++, count++);
qsort(theunit->denominator, count, sizeof(char *), compare);
}
void
cancelunit(struct unittype * theunit)
{
char **den, **num;
int comp;
den = theunit->denominator;
num = theunit->numerator;
while (*num && *den) {
comp = strcmp(*den, *num);
if (!comp) {
/* if (*den!=NULLUNIT) free(*den);
if (*num!=NULLUNIT) free(*num);*/
*den++ = NULLUNIT;
*num++ = NULLUNIT;
}
else if (comp < 0)
den++;
else
num++;
}
}
/*
Looks up the definition for the specified unit.
Returns a pointer to the definition or a null pointer
if the specified unit does not appear in the units table.
*/
static char buffer[100]; /* buffer for lookupunit answers with
prefixes */
char *
lookupunit(const char *unit)
{
int i;
char *copy;
for (i = 0; i < unitcount; i++) {
if (!strcmp(unittable[i].uname, unit))
return unittable[i].uval;
}
if (unit[strlen(unit) - 1] == '^') {
copy = dupstr(unit);
copy[strlen(copy) - 1] = 0;
for (i = 0; i < unitcount; i++) {
if (!strcmp(unittable[i].uname, copy)) {
strlcpy(buffer, copy, sizeof(buffer));
free(copy);
return buffer;
}
}
free(copy);
}
if (unit[strlen(unit) - 1] == 's') {
copy = dupstr(unit);
copy[strlen(copy) - 1] = 0;
for (i = 0; i < unitcount; i++) {
if (!strcmp(unittable[i].uname, copy)) {
strlcpy(buffer, copy, sizeof(buffer));
free(copy);
return buffer;
}
}
if (copy[strlen(copy) - 1] == 'e') {
copy[strlen(copy) - 1] = 0;
for (i = 0; i < unitcount; i++) {
if (!strcmp(unittable[i].uname, copy)) {
strlcpy(buffer, copy, sizeof(buffer));
free(copy);
return buffer;
}
}
}
free(copy);
}
for (i = 0; i < prefixcount; i++) {
size_t len = strlen(prefixtable[i].prefixname);
if (!strncmp(prefixtable[i].prefixname, unit, len)) {
if (!strlen(unit + len) || lookupunit(unit + len)) {
snprintf(buffer, sizeof(buffer), "%s %s",
prefixtable[i].prefixval, unit + len);
return buffer;
}
}
}
return 0;
}
/*
reduces a product of symbolic units to primitive units.
The three low bits are used to return flags:
bit 0 (1) set on if reductions were performed without error.
bit 1 (2) set on if no reductions are performed.
bit 2 (4) set on if an unknown unit is discovered.
*/
#define ERROR 4
int
reduceproduct(struct unittype * theunit, int flip)
{
char *toadd;
char **product;
int didsomething = 2;
if (flip)
product = theunit->denominator;
else
product = theunit->numerator;
for (; *product; product++) {
for (;;) {
if (!strlen(*product))
break;
toadd = lookupunit(*product);
if (!toadd) {
printf("unknown unit '%s'\n", *product);
return ERROR;
}
if (strchr(toadd, PRIMITIVECHAR))
break;
didsomething = 1;
if (*product != NULLUNIT) {
free(*product);
*product = NULLUNIT;
}
if (addunit(theunit, toadd, flip, 0))
return ERROR;
}
}
return didsomething;
}
/*
Reduces numerator and denominator of the specified unit.
Returns 0 on success, or 1 on unknown unit error.
*/
int
reduceunit(struct unittype * theunit)
{
int ret;
ret = 1;
while (ret & 1) {
ret = reduceproduct(theunit, 0) | reduceproduct(theunit, 1);
if (ret & 4)
return 1;
}
return 0;
}
int
compareproducts(char **one, char **two)
{
while (*one || *two) {
if (!*one && *two != NULLUNIT)
return 1;
if (!*two && *one != NULLUNIT)
return 1;
if (*one == NULLUNIT)
one++;
else if (*two == NULLUNIT)
two++;
else if (strcmp(*one, *two))
return 1;
else
one++, two++;
}
return 0;
}
/* Return zero if units are compatible, nonzero otherwise */
int
compareunits(struct unittype * first, struct unittype * second)
{
return
compareproducts(first->numerator, second->numerator) ||
compareproducts(first->denominator, second->denominator);
}
int
completereduce(struct unittype * unit)
{
if (reduceunit(unit))
return 1;
sortunit(unit);
cancelunit(unit);
return 0;
}
void
showanswer(struct unittype * have, struct unittype * want)
{
if (compareunits(have, want)) {
printf("conformability error\n");
showunit(have);
showunit(want);
}
else if (have->offset != want->offset) {
if (want->quantity)
printf("WARNING: conversion of non-proportional quantities.\n");
printf("\t");
if (have->quantity)
printf("%.8g\n",
(have->factor + have->offset-want->offset)/want->factor);
else
printf(" (-> x*%.8g %+.8g)\n\t (<- y*%.8g %+.8g)\n",
have->factor / want->factor,
(have->offset-want->offset)/want->factor,
want->factor / have->factor,
(want->offset - have->offset)/have->factor);
}
else
printf("\t* %.8g\n\t/ %.8g\n", have->factor / want->factor,
want->factor / have->factor);
}
void
usage(void)
{
fprintf(stderr,
"usage: units [-f unitsfile] [-q] [-v] [from-unit to-unit]\n");
exit(3);
}
int
main(int argc, char **argv)
{
struct unittype have, want;
char havestr[81], wantstr[81];
int optchar;
char *userfile = 0;
int quiet = 0;
while ((optchar = getopt(argc, argv, "Vqf:")) != -1) {
switch (optchar) {
case 'f':
userfile = optarg;
break;
case 'q':
quiet = 1;
break;
case 'V':
fprintf(stderr, "FreeBSD units\n");
usage();
break;
default:
usage();
}
}
if (optind != argc - 2 && optind != argc)
usage();
readunits(userfile);
if (optind == argc - 2) {
strlcpy(havestr, argv[optind], sizeof(havestr));
strlcpy(wantstr, argv[optind + 1], sizeof(wantstr));
initializeunit(&have);
addunit(&have, havestr, 0, 1);
completereduce(&have);
initializeunit(&want);
addunit(&want, wantstr, 0, 1);
completereduce(&want);
showanswer(&have, &want);
}
else {
if (!quiet)
printf("%d units, %d prefixes\n", unitcount,
prefixcount);
for (;;) {
do {
initializeunit(&have);
if (!quiet)
printf("You have: ");
if (!fgets(havestr, sizeof(havestr), stdin)) {
if (!quiet)
putchar('\n');
exit(0);
}
} while (addunit(&have, havestr, 0, 1) ||
completereduce(&have));
do {
initializeunit(&want);
if (!quiet)
printf("You want: ");
if (!fgets(wantstr, sizeof(wantstr), stdin)) {
if (!quiet)
putchar('\n');
exit(0);
}
} while (addunit(&want, wantstr, 0, 1) ||
completereduce(&want));
showanswer(&have, &want);
}
}
return(0);
}