RPNCalc

RPNCalc is the command-line based Reverse Polish Notation (RPN) calculator.
RPN calculators make it very simple to do complex calculations, especially
if there are parentheses involved. In essence, you enter your numbers first,
and then the operator.

So, to add 2 and 3 to get 5, you would first add the number 2 to the stack.
Then you would add 5 to the stack (pushing the 2 to the second position.)
Now, to add them you would enter + and RPNCalc would remove the 2 and 3
from the stack, add them, and push 5 back onto the stack.

There is a very large collection of functions that can be used. Trig functions,
statistical functions, user defined functions, multiple stacks, constants, etc.

For a quick summary of RPNCalc usage, run the program with the -h switch or enter h
within the program.

Please take a look at the User guide for detailed information on what
RPNCalc is and how to use it. Once you use an RPN calculator,
it's hard to go back to a traditional one.

Homepage: https://github.com/frossm/rpncalc
RPNCalc user guide: https://frossm.github.io/RPNCalc-UserGuide