Postfix calculator

Simple cli calculator using reverse Polish notation. Part of datastructures and algorithms course.

Usage

postfix [OPTION] or postfix [EXPRESSION]

• Options:

  • -h Prints summarized message about usage.
  • -p Starts postfix calculator with prompt.

• Commands:

  • q Quits prompt.
  • p Prints top entry of stack.
  • f Prints entries of whole stack.
  • c Clears stack.
  • x Exchanges values of two top entries together.

• Arithmetic operations:

  • + Pops two top entries from stack, sums them and pushes result to stack.
  • - Pops two top entries from stack, subtracts first popped from second and pushes result to stack.
  • * Pops two top entries from stack, multiplies them together and pushes result to stack. Use \* when using as cli argument.
  • / Pops two top entries form stack, divides second popped with first popped and pushes result to stack.
  • % Pops two top entries from stack, calculates remainder of division and pushes result to stack.
  • ^ Pops two top entries from stack, calculates power by using first as exponent and second as base. Pushes result to stack.
  • v Pops top entry from stack, calculates square root and pushes result to stack.
  • s Pops all entries from stack, sums them and pushes result to stack.
  • a Pops all entries from stack, calculates average and pushes result to stack.

Examples

$ postfix 12 10 * p 
> 120

$ postfix -p
>>> 2 3 + p 
> 5
>>> 4 5 6 f 
> 6
> 5
> 4 
> 5
>>> s p q
> 20