RPN

A Reverse Polish Notation calculator using double precision and supporting most standard scientific calculator operations.

Expressions can be passed as shell arguments, in which case they will be interpreted separately, with each result printed on a new line. There is also an interactive mode, which allows the user to evaluate expressions in the context of a single stack.

Compilation

Simply compile with gcc -o rpn *.c

Running

Get help on usage:

$ rpn --help
Usage: rpn ...

Evaluate 1 + 2 (note the quotes; necessary to express a single expression):

$ rpn '1 2 +'
3

Evaluate pi^2 and log(1.1):

$ rpn 'pi 2 ^' '1.1 log'
9.8696
0.0953102

Enter interactive mode (note print to show the state of the stack):

rpn $ ./rpn        
>>> 1 1 +
2
>>> 3 *
6
>>> e
2.71828
>>> print
.--------------.
[       2.7183 ]
[            6 ]
'--------------'
>>> %
0.563436
>>> print
.--------------.
[      0.56344 ]
'--------------'
>>> quit