Shell independent helper functions

[thorncp]

Historically, I've had a collection of helper functions, first written in bash, then ported to zsh, now partially ported to fish. Porting these is not how I want to spend my time. Is it worth the effort of writing them to be shell independent, then (hopefully) never having this problem again?

Desires:

• Not written in sh/bash/zsh. These are not enjoyable to author and are a pain to maintain

• Performance is priority. My first thought is to use Ruby for everything, but the startup costs may be too high. E.g.

    % time sh -c ""
            0.00 real         0.00 user         0.00 sys
    % time ruby -e ""
            0.28 real         0.16 user         0.09 sys
  

See also:

• Old zsh functions: https://github.com/thorncp/dotfiles/tree/97374f0/zsh/functions
• Ported fish functions: https://github.com/thorncp/dotfiles/tree/3623665/config/fish/functions