This project is currently in its early stages, though it already works well enough for contributors to dogfood it as their daily driver. Its design is subject to change as it matures.
Nu has a list of built-in commands (listed below). If a command is unknown, the command will shell-out and execute it (using cmd on Windows or bash on Linux and MacOS), correctly passing through stdin, stdout and stderr, so things like your daily git workflows and even `vim` will work just fine.
Nu draws inspiration from projects like PowerShell, functional programming languages, and modern cli tools. Rather than thinking of files and services as raw streams of text, Nu looks at each input as something with structure. For example, when you list the contents of a directory, what you get back in a list of objects, where each object represents an item in that directory. These values can be piped through a series of steps, in a series of commands called a 'pipeline'.
In Unix, it's common to pipe between commands to split up a sophisticated command over multiple steps. Nu takes this a step further and builds heavily on the idea of _pipelines_. Just as the Unix philosophy, Nu allows commands to output from stdout and read from stdin. Additionally, commands can output structured data (you can think of this as a third kind of stream). Commands that work in the pipeline fit into one of three categories
Being able to use the same commands and compose them differently is an important philosophy in Nu. For example, we could use the built-in `ps` command as well to get a list of the running processes, using the same `where` as above.
Nu can load file and URL contents as raw text or as structured data (if it recognizes the format). For example, you can load a .toml file as structured data and explore it:
```
/home/jonathan/Source/nushell(master)> open Cargo.toml
By default, Nu will work inside of a single directory and allow you to navigate around your filesystem. Sometimes, you'll want to work in multiple directories at the same time. For this, Nu offers a way of adding additional working directories that you can jump between.
To do so, use the `enter` command, which will allow you create a new "shell" and enter it at the specified path. You can toggle between this new shell and the original shell with the `p` (for previous) and `n` (for next), allowing you to navigate around a ring buffer of shells. Once you're done with a shell, you can `exit` it and remove it from the ring buffer.
Nu supports plugins that offer additional functionality to the shell and follow the same object model that built-in commands use. This allows you to extend nu for your needs.
Plugins are binaries that are available in your path and follow a "nu_plugin_*" naming convention. These binaries interact with nu via a simple JSON-RPC protocol where the command identifies itself and passes along its configuration, which then makes it available for use. If the plugin is a filter, data streams to it one element at a time, and it can stream data back in return via stdin/stdout. If the plugin is a sink, it is given the full vector of final data and is given free reign over stdin/stdout to use as it pleases.
Nu adheres closely to a set of goals that make up its design philosophy. As features are added, they are checked against these goals.
* First and foremost, Nu is cross-platform. Commands and techniques should carry between platforms and offer first-class consistent support for Windows, macOS, and Linux.
* Nu ensures direct compatibility with existing platform-specific executables that make up people's workflows.
* Nu's workflow and tools should have the usability in day-to-day experience of using a shell in 2019 (and beyond).
* Nu views data as both structured and unstructured. It is an object shell like PowerShell.
