NetBSD-5.0.2/usr.bin/units/units.c
/* $NetBSD: units.c,v 1.15 2006/05/01 00:00:12 christos Exp $ */
/*
* 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.
*/
#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "pathnames.h"
#define VERSION "1.0"
#ifndef UNITSFILE
#define UNITSFILE _PATH_UNITSLIB
#endif
#define MAXUNITS 1000
#define MAXPREFIXES 50
#define MAXSUBUNITS 500
#define PRIMITIVECHAR '!'
char *powerstring = "^";
struct {
char *uname;
char *uval;
} unittable[MAXUNITS];
struct unittype {
char *numerator[MAXSUBUNITS];
char *denominator[MAXSUBUNITS];
double factor;
};
struct {
char *prefixname;
char *prefixval;
} prefixtable[MAXPREFIXES];
char *NULLUNIT = "";
int unitcount;
int prefixcount;
int addsubunit __P((char *[], char *));
int addunit __P((struct unittype *, char *, int));
void cancelunit __P((struct unittype *));
int compare __P((const void *, const void *));
int compareproducts __P((char **, char **));
int compareunits __P((struct unittype *, struct unittype *));
int compareunitsreciprocal __P((struct unittype *, struct unittype *));
int completereduce __P((struct unittype *));
void initializeunit __P((struct unittype *));
int main __P((int, char **));
void readerror __P((int));
void readunits __P((char *));
int reduceproduct __P((struct unittype *, int));
int reduceunit __P((struct unittype *));
void showanswer __P((struct unittype *, struct unittype *));
void showunit __P((struct unittype *));
void sortunit __P((struct unittype *));
void usage __P((void));
void zeroerror __P((void));
char *dupstr __P((char *));
char *lookupunit __P((char *));
char *
dupstr(char *str)
{
char *ret;
ret = strdup(str);
if (!ret)
err(3, "Memory allocation error");
return (ret);
}
void
readerror(int linenum)
{
warnx("Error in units file '%s' line %d", UNITSFILE, linenum);
}
void
readunits(char *userfile)
{
FILE *unitfile;
char line[80], *lineptr;
int len, linenum, i;
unitcount = 0;
linenum = 0;
if (userfile) {
unitfile = fopen(userfile, "rt");
if (!unitfile)
err(1, "Unable to open units file '%s'", userfile);
}
else {
unitfile = fopen(UNITSFILE, "rt");
if (!unitfile) {
char *direc, *env;
char filename[1000];
char separator[2];
env = getenv("PATH");
if (env) {
if (strchr(env, ';'))
strlcpy(separator, ";",
sizeof(separator));
else
strlcpy(separator, ":",
sizeof(separator));
direc = strtok(env, separator);
while (direc) {
strlcpy(filename, "", sizeof(filename));
strlcat(filename, direc,
sizeof(filename));
strlcat(filename, "/",
sizeof(filename));
strlcat(filename, UNITSFILE,
sizeof(filename));
unitfile = fopen(filename, "rt");
if (unitfile)
break;
direc = strtok(NULL, separator);
}
}
if (!unitfile)
errx(1, "Can't find units file '%s'",
UNITSFILE);
}
}
while (!feof(unitfile)) {
if (!fgets(line, 79, 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;
if (!strlen(lineptr)) {
readerror(linenum);
continue;
}
lineptr += strspn(lineptr, " \n\t");
len = strcspn(lineptr, "\n\t");
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)) {
readerror(linenum);
continue;
}
len = strcspn(lineptr, "\n\t");
lineptr[len] = 0;
unittable[unitcount++].uval = dupstr(lineptr);
}
}
fclose(unitfile);
}
void
initializeunit(struct unittype * theunit)
{
theunit->factor = 1.0;
theunit->numerator[0] = theunit->denominator[0] = NULL;
}
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);
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()
{
warnx("Unit reduces to zero");
}
/*
Adds the specified string to the unit.
Flip is 0 for adding normally, 1 for adding reciprocal.
Returns 0 for successful addition, nonzero on error.
*/
int
addunit(struct unittype * theunit, char *toadd, int flip)
{
char *scratch, *savescr;
char *item;
char *divider, *slash;
int doingtop;
savescr = scratch = dupstr(toadd);
for (slash = scratch + 1; *slash; slash++)
if (*slash == '-' &&
(tolower((unsigned char)*(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;
divider = strchr(item, '|');
if (divider) {
*divider = 0;
num = atof(item);
if (!num) {
zeroerror();
return 1;
}
if (doingtop ^ flip)
theunit->factor *= num;
else
theunit->factor /= num;
num = atof(divider + 1);
if (!num) {
zeroerror();
return 1;
}
if (doingtop ^ flip)
theunit->factor /= num;
else
theunit->factor *= num;
}
else {
num = atof(item);
if (!num) {
zeroerror();
return 1;
}
if (doingtop ^ flip)
theunit->factor *= num;
else
theunit->factor /= num;
}
}
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(*(char **) item1, *(char **) item2);
}
void
sortunit(struct unittype * theunit)
{
char **ptr;
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(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++) {
if (!strncmp(prefixtable[i].prefixname, unit,
strlen(prefixtable[i].prefixname))) {
unit += strlen(prefixtable[i].prefixname);
if (!strlen(unit) || lookupunit(unit)) {
strlcpy(buffer, prefixtable[i].prefixval,
sizeof(buffer));
strlcat(buffer, " ", sizeof(buffer));
strlcat(buffer, unit, sizeof(buffer));
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))
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 (*one && *two && 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
compareunitsreciprocal(struct unittype * first, struct unittype * second)
{
return
compareproducts(first->numerator, second->denominator) ||
compareproducts(first->denominator, second->numerator);
}
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)) {
if (compareunitsreciprocal(have, want)) {
printf("conformability error\n");
showunit(have);
showunit(want);
} else {
printf("\treciprocal conversion\n");
printf("\t* %.8g\n\t/ %.8g\n", 1 / (have->factor * want->factor),
want->factor * have->factor);
}
}
else
printf("\t* %.8g\n\t/ %.8g\n", have->factor / want->factor,
want->factor / have->factor);
}
void
usage()
{
fprintf(stderr,
"\nunits [-f unitsfile] [-q] [-v] [from-unit to-unit]\n");
fprintf(stderr, "\n -f specify units file\n");
fprintf(stderr, " -q suppress prompting (quiet)\n");
fprintf(stderr, " -v print version number\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, "\n units version %s Copyright (c) 1993 by Adrian Mariano\n",
VERSION);
fprintf(stderr, " This program may be freely distributed\n");
usage();
default:
usage();
break;
}
}
argc -= optind;
argv += optind;
if (argc != 3 && argc != 2 && argc != 0)
usage();
readunits(userfile);
if (argc == 3) {
strlcpy(havestr, argv[0], sizeof(havestr));
strlcat(havestr, " ", sizeof(havestr));
strlcat(havestr, argv[1], sizeof(havestr));
argc--;
argv++;
argv[0] = havestr;
}
if (argc == 2) {
strlcpy(havestr, argv[0], sizeof(havestr));
strlcpy(wantstr, argv[1], sizeof(wantstr));
initializeunit(&have);
addunit(&have, havestr, 0);
completereduce(&have);
initializeunit(&want);
addunit(&want, wantstr, 0);
completereduce(&want);
showanswer(&have, &want);
}
else {
if (!quiet)
printf("%d units, %d prefixes\n\n", unitcount,
prefixcount);
for (;;) {
do {
initializeunit(&have);
if (!quiet)
printf("You have: ");
if (!fgets(havestr, 80, stdin)) {
if (!quiet)
putchar('\n');
exit(0);
}
} while (addunit(&have, havestr, 0) ||
completereduce(&have));
do {
initializeunit(&want);
if (!quiet)
printf("You want: ");
if (!fgets(wantstr, 80, stdin)) {
if (!quiet)
putchar('\n');
exit(0);
}
} while (addunit(&want, wantstr, 0) ||
completereduce(&want));
showanswer(&have, &want);
}
}
return (0);
}