calccu

calccu is a small interactive terminal calculator. It updates the result while you type, and pressing Enter commits the current expression so the result becomes available as ans. Committed inputs and results stay visible as a short on-screen history above the prompt. Calculator answers are shown with a leading <.

Install

From this directory:

npm install -g .

Then run:

calccu

For local development:

npm start
npm test

You can also run one expression without opening the TUI:

calccu "2 + 2"
echo "2x = 3" | calccu
calccu --help
calccu --version

Keys

• Enter commits the current input.
• Ctrl+C quits.
• Ctrl+L clears the terminal.
• Left and right arrows move the cursor.
• Up and down arrows recall previous commands.
• PageUp/PageDown scroll visible-session results.
• Home/End or Ctrl+A/Ctrl+E move to the start/end.
• Ctrl+U/Ctrl+K delete before/after the cursor.
• Ctrl+W deletes the previous word.

Commands

help
?
clear
clear history
quit
exit
vars
funcs
ls vars
ls funcs
history
units
precision
precision 8
del name
delete name
del var name
del fn name

clear and Ctrl+L clear the visible calculator history. Command recall is saved between sessions in ~/.calccu_history.

Examples

2 + 3 * 4
2m + 30cm
5km to m
32F to C
1MiB to B

x = 12
2x + 1

f(x) = x^2 + 1
f(3)

2x = 3
3(x - 1) = 9
x/2 = 3
1/3x = 2
x^2 - 4 = 0

Supported Math

• Operators: +, -, *, /, ^
• Parentheses
• Implicit multiplication, such as 2x and 3(x + 1)
• Variables
• User-defined functions
• Fraction-style input through division, such as 1/3x = 2
• Unit categories: temperature, length, weight, area, volume, energy, speed, time, and data
• Unit conversion with to, such as 5km to m
• Configurable displayed significant digits with precision 8
• Built-in constants: pi, e
• Built-in functions: abs, acos, asin, atan, ceil, cos, exp, floor, ln, log, max, min, round, sin, sqrt, tan

Equation solving supports exact single-variable linear equations and quadratic equations up to degree two. Linear solutions are kept exact where possible, such as 2x = 3 producing x = 3/2.

Supported units:

• Temperature: C, F, K, degC, degF
• Length: mm, cm, m, km, in, ft, yd, mi
• Weight: mg, g, kg, t, oz, lb, st
• Area: m2, cm2, km2, ft2, in2, acre, ha
• Volume: m3, cm3, mm3, L, l, mL, ml, gal, qt, pt, cup, fl_oz
• Energy: J, kJ, cal, kcal, Wh, kWh, BTU, btu
• Speed: mps, kmh, mph, knot, fps
• Time: ms, s, min, h, day, week
• Data: bit, b, B, KB, MB, GB, TB, KiB, MiB, GiB, TiB