turtle is a reimplementation of the Unix command line environment in
Haskell so that you can use Haskell as both a shell and a scripting
language.

Features include:
* Batteries included: Command an extended suite of predefined utilities
* Interoperability: You can still run external shell commands
* Portability: Works on Windows, OS X, and Linux
* Exception safety: Safely acquire and release resources
* Streaming: Transform or fold command output in constant space
* Patterns: Use typed regular expressions that can parse structured values
* Formatting: Type-safe printf-style text formatting
* Modern: Supports text and system-filepath