moo is a simple calculator that accepts C-like syntax as input.
Calculations are done on expr, if given. Otherwise, the standard input is used.
Numbers can be entered in hexadecimal (0xbeef), decimal (1984), octal (007),
and binary (0b1001). All numerical operators (+, -, *, /, %), bit operators
(|, ^, &, ~, <<, >>), and logical operators (==, !=, <, >, <=, >=, !, &&, ||)
Submitted by: Steven Kreuzer <skreuzer at f2o.org>