ev

Description

Unix utility to compute the min, max, and expected value of a D&D-like dice roll.

Compilation

ev can be built using Rust's cargo tool:

$ cargo build --release

Usage

ev can be used in two ways: it can read a list of rolls from the positional command-line arguments and output their statistics, or, if no positional arguments are given, it can read rolls from stdin. By default, the output is spread across multiple lines, in a way that is easy to read for a human.

$ ev 1d6 3d4+1
1d6:
        min: 1
        max: 6
        ev : 3.5
3d4+1:
        min: 4
        max: 13
        ev : 8.5

$ echo 5d8-4 | ev
5d8-4:
        min: 1
        max: 36
        ev : 18.5

If the ev command is to be used as part of a Unix pipe-line, the -s flag is helpful: the output for each dice roll will be on a single line, making integration with tools like awk or sed simpler.

$ ev -s 1d6 3d4+1
1d6 1 6 3.5
3d4+1 4 13 8.5

$ ev -s 2d6 1d8+2 3d4+1 | column -t
2d6    2  12  7
1d8+2  3  10  6.5
3d4+1  4  13  8.5