Unix utility for conversion of infix-form expressions into reverse polish notation (postfix) format
Usage: rpn [-p precision] [-ehsV] [--version] [--help] ["<expression>"].
Don't forget to use quote marks and parentheses.
-p precision Number of digits shown after the decimal point.
-s Output in scientific format (e.g. 2.45e2, 1.5e-3).
-e Evaluate expression (instead of conversion).
-V --version Print version and exit...
-h, -? --help Prints this help message.