File: ca.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright (c) 2026 pacman64
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the "Software"), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23 # SOFTWARE.
  24 
  25 
  26 # ca [expressions...]
  27 #
  28 # CAlculator is an easier-to-use way of running `bc` (basic calculator) where
  29 #
  30 #   - you can calculate multiple different things in one run
  31 #   - you give the expressions as arguments, while `bc` uses stdin
  32 #   - you don't need quoting when avoiding parentheses and spaces
  33 #   - you can use either ** or ^ to raise powers
  34 #   - you can use [ and ] or ( and ) interchangeably
  35 #   - the number of max-accuracy decimals is 25 by default
  36 #   - automatically includes the extended bc math library via option -l
  37 #   - there are several extra predefined values, functions, and aliases
  38 #   - unneeded trailing decimal zeros are ignored for final outputs
  39 
  40 
  41 quiet=0
  42 
  43 case "$1" in
  44     -h|--h|-help|--help)
  45         awk '/^# +ca /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  46         exit 0
  47     ;;
  48 
  49     -q|--q|-quiet|--quiet)
  50         quiet=1
  51         shift
  52     ;;
  53 esac
  54 
  55 [ "$1" = '--' ] && shift
  56 
  57 if [ $# -eq 0 ]; then
  58     awk '/^# +ca /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  59     exit 0
  60 fi
  61 
  62 # default max-accuracy decimals to use for calculations
  63 scale=25
  64 
  65 src='
  66 femto = 0.000000000000001;
  67 pico = 0.000000000001;
  68 nano = 0.000000001;
  69 micro = 0.000001;
  70 milli = 0.001;
  71 
  72 kilo = 1000;
  73 mega = 1000 * kilo;
  74 giga = 1000 * mega;
  75 tera = 1000 * giga;
  76 peta = 1000 * tera;
  77 exa =  1000 * peta;
  78 zetta =  1000 * exa;
  79 
  80 binkilo = 1024;
  81 binmega = 1024 * binkilo;
  82 bingiga = 1024 * binmega;
  83 bintera = 1024 * bingiga;
  84 binpeta = 1024 * bintera;
  85 binexa = 1024 * binpeta;
  86 binzetta = 1024 * binexa;
  87 
  88 kb = 1024;
  89 mb = 1024 * kb;
  90 gb = 1024 * mb;
  91 tb = 1024 * gb;
  92 pb = 1024 * tb;
  93 eb = 1024 * pb;
  94 zb = 1024 * eb;
  95 
  96 kib = 1024;
  97 mib = 1024 * kib;
  98 gib = 1024 * mib;
  99 tib = 1024 * gib;
 100 pib = 1024 * tib;
 101 zib = 1024 * pib;
 102 
 103 mol = 602214076000000000000000;
 104 mole = 602214076000000000000000;
 105 
 106 cup = 0.23658824;
 107 cup2l = 0.23658824;
 108 floz2l = 0.0295735295625;
 109 floz2ml = 29.5735295625;
 110 ft = 0.3048;
 111 ft2m = 0.3048;
 112 gal = 3.785411784;
 113 gal2l = 3.785411784;
 114 in = 2.54;
 115 in2cm = 2.54;
 116 lb = 0.45359237;
 117 lb2kg = 0.45359237;
 118 mi = 1.609344;
 119 mi2km = 1.609344;
 120 mpg = 0.425143707;
 121 mpg2kpl = 0.425143707;
 122 nm = 1.852;
 123 nm2km = 1.852;
 124 nmi = 1.852;
 125 nmi2km = 1.852;
 126 oz2g = 28.349523125
 127 psi2pa = 6894.757293168;
 128 ton = 907.18474;
 129 ton2kg = 907.18474;
 130 yd = 0.9144;
 131 yd2m = 0.9144;
 132 
 133 ga2l = gal2l;
 134 nm2km = nmi2km;
 135 tn2kg = ton2kg;
 136 
 137 million = 1000000;
 138 billion = 1000 * million;
 139 trillion = 1000 * billion;
 140 
 141 hour = 3600;
 142 day = 24 * hour;
 143 week = 7 * day;
 144 
 145 hr = hour;
 146 wk = week;
 147 
 148 /* function "choose": "bc" uses "c" for the built-in cosine function */
 149 
 150 define abs(x) { if (x >= 0) return (x) else return (-x); }
 151 define atan(x) { return (a(x)); }
 152 define bits(x) { return (log2(x)); }
 153 define ceil(x) { return (ceiling(x)); }
 154 define choose(n, k) { return (com(n, k)); }
 155 define circle(r) { return (4 * a(1) * r * r); } /* circle-area from radius */
 156 define circum(r) { return (8 * a(1) * r); } /* circumference from radius */
 157 define circumference(r) { return (8 * a(1) * r); }
 158 define com(n, k) { if (n < k) return (0) else return (per(n, k) / fac(k)); }
 159 define comb(n, k) { return (com(n, k)); }
 160 define combin(n, k) { return (com(n, k)); }
 161 define combinations(n, k) { return (com(n, k)); }
 162 define cos(x) { return (c(x)); }
 163 define cosh(x) { return ((e(x) + e(-x)) / 2); }
 164 define cot(x) { return (c(x) / s(x)); }
 165 define coth(x) { return ((e(x) + e(-x)) / (e(x) - e(-x))); }
 166 define dbin(x, n, p) { return (dbinom(x, n, p)); }
 167 define dbinom(x, n, p) { return (com(n, x) * (p ^ x) * ((1 - p) ^ (n - x))); }
 168 define deg(x) { return (180 * x / pi()); }
 169 define digits(x) { return (log10(x)); }
 170 define degrees(x) { return (deg(x)); }
 171 define dexp(x, r) { if (r < 0) return (0) else return (r * e(-r * x)); }
 172 define dpois(x, l) { return ((l ^ x) * e(-l) / fac(x)); }
 173 define gauss(x) { return (gaussian(x)); }
 174 define gaussian(x) { return (e(-(x * x))); }
 175 define epa(x) { return (epanechnikov(x)); }
 176 define eu() { return (e(1)); }
 177 define euler() { return (e(1)); }
 178 define exp(x) { return (e(x)); }
 179 define f(x) { return (fac(x)); }
 180 define fact(x) { return (fac(x)); }
 181 define factorial(x) { return (fac(x)); }
 182 define ftin(f, i) { return (0.3048 * f + 0.0254 * i); }
 183 define gcd(x, y) { return (x * y / lcm(x, y)); }
 184 define hypot(x, y) { return (sqrt(x*x + y*y)); }
 185 define j0(x) { return (j(0, x)); }
 186 define j1(x) { return (j(1, x)); }
 187 define lboz(l, o) { return (0.45359237 * l + 0.028349523 * o); }
 188 define ln(x) { return (l(x)); }
 189 define log(x) { return (l(x)); }
 190 define logistic(x) { return (1 / (1 + e(-x))); }
 191 define max(x, y) { if (x >= y) return (x) else return (y); }
 192 define min(x, y) { if (x <= y) return (x) else return (y); }
 193 define mix(x, y, k) { return (x * (1 - k) + y * k); }
 194 define mod1(x) { return (mod(x, 1)); }
 195 define modf(x) { return (mod(x, 1)); }
 196 define p(n, k) { return (per(n, k)); }
 197 define pbin(x, n, p) { return (pbinom(x, n, p)); }
 198 define perm(n, k) { return (per(n, k)); }
 199 define permut(n, k) { return (per(n, k)); }
 200 define permutations(n, k) { return (per(n, k)); }
 201 define pexp(x, r) { if (r < 0) return (0) else return (1 - e(-r * x)); }
 202 define pi() { return (4 * a(1)); }
 203 define pow2(x) { return (2 ^ x); }
 204 define power2(x) { return (2 ^ x); }
 205 define pow10(x) { return (10 ^ x); }
 206 define power10(x) { return (10 ^ x); }
 207 define r(x, d) { return (round(x, d)); }
 208 define r0(x) { return (round0(x)); }
 209 define rad(x) { return (pi() * x / 180); }
 210 define radians(x) { return (rad(x)); }
 211 define sgn(x) { return (sgn(x)); }
 212 define sin(x) { return (s(x)); }
 213 define sinc(x) { if (x == 0) return (1) else return (s(x) / x); }
 214 define sinh(x) { return ((e(x) - e(-x)) / 2); }
 215 define tan(x) { return (s(x) / c(x)); }
 216 define tanh(x) { return ((e(x) - e(-x)) / (e(x) + e(-x))); }
 217 define tau() { return (8 * a(1)); }
 218 
 219 define ceiling(x) {
 220     auto s, r;
 221     s = scale;
 222     scale = 0;
 223     r = x % 1;
 224     scale = s;
 225     if (r == 0) return (x);
 226     if (x < 0) return (x - r);
 227     return (x - r + 1);
 228 }
 229 
 230 define epanechnikov(x) {
 231     if ((x < -1) || (x > 1)) return (0);
 232     return (3 / 4 * (1 - (x * x)));
 233 }
 234 
 235 define fac(x) {
 236     auto f, i;
 237     if (x < 0) return (0);
 238     f = 1;
 239     for (i = x; i >= 2; i--) f *= i;
 240     return (f);
 241 }
 242 
 243 define floor(x) {
 244     auto s, r;
 245     s = scale;
 246     scale = 0;
 247     r = x % 1;
 248     scale = s;
 249     if (r == 0) return (x);
 250     if (x < 0) return (x - r - 1);
 251     return (x - r);
 252 }
 253 
 254 define lcm(x, y) {
 255     auto a, b, z;
 256     a = x;
 257     b = y;
 258     if (a > b) {
 259         a = y;
 260         b = x;
 261     }
 262 
 263     /* the LCM is defined only for positive integers */
 264     if (mod(x, 1) != 0 || x < 1 || mod(y, 1) != 0 || y < 1) return (0);
 265 
 266     z = b;
 267     while (mod(z, a) != 0) { z += b; }
 268     return (z);
 269 }
 270 
 271 define log2(x) {
 272     auto r, n;
 273     if (x <= 0) return (l(x) / l(2));
 274 
 275     r = 0;
 276     for (n = x; n > 1; n /= 2) r += 1;
 277 
 278     if (n == 1) return (r);
 279     return (l(x) / l(2));
 280 }
 281 
 282 define log10(x) {
 283     auto r, n;
 284     if (x <= 0) return (l(x) / l(10));
 285 
 286     r = 0;
 287     for (n = x; n > 1; n /= 10) r += 1;
 288 
 289     if (n == 1) return (r);
 290     return (l(x) / l(10));
 291 }
 292 
 293 define mod(x, y) {
 294     auto s, m;
 295     s = scale;
 296     scale = 0;
 297     m = x % y;
 298     scale = s;
 299     return (m);
 300 }
 301 
 302 define per(n, k) {
 303     auto p, i;
 304     if (n < k) return (0);
 305     p = 1;
 306     for (i = n; i >= n - k + 1; i--) p *= i;
 307     return (p);
 308 }
 309 
 310 /* pbinom inefficiently repeats calculations for now, which keeps it simple */
 311 define pbinom(x, n, p) {
 312     auto k, t;
 313     t = 0;
 314     for (k = 0; k <= n; k++) t += dbinom(k, n, p);
 315     return (t);
 316 }
 317 
 318 /* pbinomfast may be wrong, while the simpler pbinom seems correct */
 319 define pbinomfast(x, n, p) {
 320     auto a, b, d, q, k, t;
 321     if ((p < 0) || (p > 1)) return (0);
 322     if (x < 0) return (0);
 323     if (x >= n) return (1);
 324     a = 1;
 325     q = 1 - p;
 326     b = b ^ n;
 327     d = 1;
 328     t = 0;
 329     for (k = 0; k < x;) {
 330         t += (per(n, k) / d) * a * b;
 331         a *= p;
 332         b /= q;
 333         k++;
 334         d *= k;
 335     }
 336     /* remember the last loop, where k == x */
 337     t += (per(n, k) / d) * a * b;
 338     return (t);
 339 }
 340 
 341 define ppois(x, l) {
 342     auto t, d, i;
 343     t = 1;
 344     d = 1;
 345     for (i = 1; i <= l; i++) {
 346         d *= i;
 347         t += (l ^ i) / d;
 348     }
 349     return (e(-l) * t);
 350 }
 351 
 352 define round(x, d) {
 353     auto k;
 354     k = 10 ^ d;
 355     return (round0(x * k) / k);
 356 }
 357 
 358 define round0(x) {
 359     auto i;
 360     i = x - mod(x, 1);
 361     if (x - i >= 0.5) {
 362         return (i + 1);
 363     }
 364     return (i);
 365 }
 366 
 367 define sign(x) {
 368     if (x > 0) return (1);
 369     if (x < 0) return (-1);
 370     return (0);
 371 }
 372 
 373 define tricube(x) {
 374     auto a, b, c, d;
 375     if ((x < -1) || (x > 1)) return (0);
 376     if (x >= 0) a = x else a = -x;
 377     b = a * a * a;
 378     c = 1 - b;
 379     d = c * c * c;
 380     return (70 / 81 * d);
 381 }
 382 '
 383 
 384 code=0
 385 
 386 # ensure each output is all on 1 line, define several funcs and values, then
 387 # inject the expressions given as this script's arguments, transforming them
 388 # according to the rules described above
 389 for arg in "$@"; do
 390     if [ "${code}" -ne 0 ]; then
 391         break
 392     fi
 393 
 394     if [ "${quiet}" -eq 0 ] && [ $# -ge 2 ]; then
 395         printf "\e[7m%s\e[0m\n" "${arg}" > /dev/stderr
 396     fi
 397 
 398     c="$(echo "${arg}" | sed 's-^+--g; s-_--g; s-\*\*-^-g; s-\[-(-g; s-\]-)-g')"
 399     BC_LINE_LENGTH=0 bc -l << EOS
 400 scale = ${scale};
 401 ${src}
 402 ${c}
 403 EOS
 404     code=$?
 405 done | \
 406 
 407 # using `sed` ensures the result shows at least a zero before the decimal dot,
 408 # then rids the result of trailing zero decimals and/or trailing decimal dots
 409 sed -E 's-^\.-0.-; s/^-\./-0./; s-(\.[0-9]*[1-9])0+$-\1-; s-\.0*$--'
 410 
 411 exit "${code}"