loenard97 / calc

cli calculator using reverse polish notation

calc

A cli calculator using reverse polish notation

▶️ Usage

In reverse Polish notation operators are appended after their operands, eliminating the need for brackets.

$ calc 3 2 +
5

Accepts command line arguments, as well as stdin:

$ echo "3 2 +" | calc
5

Supported operators

Note The naming of all operators is case insensitive

Constants:

• pi Archimedes’ constant π
• e Euler's constant e

Operators that take one input value:

• ln Loagaritm base e
• log2 Logarithm base 2
• log10 Logarithm base 10
• sin Sine
• cos Cosine
• tan Tangent

Operators that take two input values:

• + Addition
• - Subtraction
• . Multiplication (Note that . is used for multiplication, because * represents a wildcard in bash)
• / Division
• log Logarithm with given base

⚠️ Invalid expressions

Invalid tokens are ignored for computation, but give a warning.

$ calc 3 __ 7 + ?? 6 /
Warning: expression contains 2 invalid tokens
 │ calc 3 __ 7 + ?? 6 /
 └────────^^─────^^────

An expression can not be computed if an operator does not have enough values on the stack to complete its operation...

$ calc 3 +
Error: not enough values on stack to apply operator
 │ calc 3 +
 └────────^

...or if at the end of the computation more than one value remains on the stack.

$ calc 3 5 7 +
Error: stack contains more than one value after applying all operators