bc19be25b1
# Description
This PR uses the new plugin protocol to intelligently keep plugin
processes running in the background for further plugin calls.
Running plugins can be seen by running the new `plugin list` command,
and stopped by running the new `plugin stop` command.
This is an enhancement for the performance of plugins, as starting new
plugin processes has overhead, especially for plugins in languages that
take a significant amount of time on startup. It also enables plugins
that have persistent state between commands, making the migration of
features like dataframes and `stor` to plugins possible.
Plugins are automatically stopped by the new plugin garbage collector,
configurable with `$env.config.plugin_gc`:
```nushell
$env.config.plugin_gc = {
# Configuration for plugin garbage collection
default: {
enabled: true # true to enable stopping of inactive plugins
stop_after: 10sec # how long to wait after a plugin is inactive to stop it
}
plugins: {
# alternate configuration for specific plugins, by name, for example:
#
# gstat: {
# enabled: false
# }
}
}
```
If garbage collection is enabled, plugins will be stopped after
`stop_after` passes after they were last active. Plugins are counted as
inactive if they have no running plugin calls. Reading the stream from
the response of a plugin call is still considered to be activity, but if
a plugin holds on to a stream but the call ends without an active
streaming response, it is not counted as active even if it is reading
it. Plugins can explicitly disable the GC as appropriate with
`engine.set_gc_disabled(true)`.
The `version` command now lists plugin names rather than plugin
commands. The list of plugin commands is accessible via `plugin list`.
Recommend doing this together with #12029, because it will likely force
plugin developers to do the right thing with mutability and lead to less
unexpected behavior when running plugins nested / in parallel.
# User-Facing Changes
- new command: `plugin list`
- new command: `plugin stop`
- changed command: `version` (now lists plugin names, rather than
commands)
- new config: `$env.config.plugin_gc`
- Plugins will keep running and be reused, at least for the configured
GC period
- Plugins that used mutable state in weird ways like `inc` did might
misbehave until fixed
- Plugins can disable GC if they need to
- Had to change plugin signature to accept `&EngineInterface` so that
the GC disable feature works. #12029 does this anyway, and I'm expecting
(resolvable) conflicts with that
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
Because there is some specific OS behavior required for plugins to not
respond to Ctrl-C directly, I've developed against and tested on both
Linux and Windows to ensure that works properly.
# After Submitting
I think this probably needs to be in the book somewhere
|
||
|---|---|---|
| .cargo | ||
| .githooks | ||
| .github | ||
| assets | ||
| benches | ||
| crates | ||
| devdocs | ||
| docker | ||
| scripts | ||
| src | ||
| tests | ||
| wix | ||
| .gitattributes | ||
| .gitignore | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| Cross.toml | ||
| LICENSE | ||
| README.md | ||
| rust-toolchain.toml | ||
| toolkit.nu | ||
| typos.toml | ||
Nushell
A new type of shell.
Table of Contents
- Status
- Learning About Nu
- Installation
- Configuration
- Philosophy
- Goals
- Officially Supported By
- Contributing
- License
Status
This project has reached a minimum-viable-product level of quality. Many people use it as their daily driver, but it may be unstable for some commands. Nu's design is subject to change as it matures.
Learning About Nu
The Nushell book is the primary source of Nushell documentation. You can find a full list of Nu commands in the book, and we have many examples of using Nu in our cookbook.
We're also active on Discord and Twitter; come and chat with us!
Installation
To quickly install Nu:
# Linux and macOS
brew install nushell
# Windows
winget install nushell
To use Nu in GitHub Action, check setup-nu for more detail.
Detailed installation instructions can be found in the installation chapter of the book. Nu is available via many package managers:
For details about which platforms the Nushell team actively supports, see our platform support policy.
Configuration
The default configurations can be found at sample_config which are the configuration files one gets when they startup Nushell for the first time.
It sets all of the default configuration to run Nushell. From here one can then customize this file for their specific needs.
To see where config.nu is located on your system simply type this command.
$nu.config-path
Please see our book for all of the Nushell documentation.
Philosophy
Nu draws inspiration from projects like PowerShell, functional programming languages, and modern CLI tools. Rather than thinking of files and data 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 is a table of rows, where each row represents an item in that directory. These values can be piped through a series of steps, in a series of commands called a 'pipeline'.
Pipelines
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. As in the Unix philosophy, Nu allows commands to output to 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:
- Commands that produce a stream (e.g.,
ls) - Commands that filter a stream (e.g.,
where type == "dir") - Commands that consume the output of the pipeline (e.g.,
table)
Commands are separated by the pipe symbol (|) to denote a pipeline flowing left to right.
> ls | where type == "dir" | table
╭────┬──────────┬──────┬─────────┬───────────────╮
│ # │ name │ type │ size │ modified │
├────┼──────────┼──────┼─────────┼───────────────┤
│ 0 │ .cargo │ dir │ 0 B │ 9 minutes ago │
│ 1 │ assets │ dir │ 0 B │ 2 weeks ago │
│ 2 │ crates │ dir │ 4.0 KiB │ 2 weeks ago │
│ 3 │ docker │ dir │ 0 B │ 2 weeks ago │
│ 4 │ docs │ dir │ 0 B │ 2 weeks ago │
│ 5 │ images │ dir │ 0 B │ 2 weeks ago │
│ 6 │ pkg_mgrs │ dir │ 0 B │ 2 weeks ago │
│ 7 │ samples │ dir │ 0 B │ 2 weeks ago │
│ 8 │ src │ dir │ 4.0 KiB │ 2 weeks ago │
│ 9 │ target │ dir │ 0 B │ a day ago │
│ 10 │ tests │ dir │ 4.0 KiB │ 2 weeks ago │
│ 11 │ wix │ dir │ 0 B │ 2 weeks ago │
╰────┴──────────┴──────┴─────────┴───────────────╯
Because most of the time you'll want to see the output of a pipeline, table is assumed.
We could have also written the above:
> ls | where type == "dir"
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 to get a list of the running processes, using the same where as above.
> ps | where cpu > 0
╭───┬───────┬───────────┬───────┬───────────┬───────────╮
│ # │ pid │ name │ cpu │ mem │ virtual │
├───┼───────┼───────────┼───────┼───────────┼───────────┤
│ 0 │ 2240 │ Slack.exe │ 16.40 │ 178.3 MiB │ 232.6 MiB │
│ 1 │ 16948 │ Slack.exe │ 16.32 │ 205.0 MiB │ 197.9 MiB │
│ 2 │ 17700 │ nu.exe │ 3.77 │ 26.1 MiB │ 8.8 MiB │
╰───┴───────┴───────────┴───────┴───────────┴───────────╯
Opening files
Nu can load file and URL contents as raw text or structured data (if it recognizes the format). For example, you can load a .toml file as structured data and explore it:
> open Cargo.toml
╭──────────────────┬────────────────────╮
│ bin │ [table 1 row] │
│ dependencies │ {record 25 fields} │
│ dev-dependencies │ {record 8 fields} │
│ features │ {record 10 fields} │
│ package │ {record 13 fields} │
│ patch │ {record 1 field} │
│ profile │ {record 3 fields} │
│ target │ {record 3 fields} │
│ workspace │ {record 1 field} │
╰──────────────────┴────────────────────╯
We can pipe this into a command that gets the contents of one of the columns:
> open Cargo.toml | get package
╭───────────────┬────────────────────────────────────╮
│ authors │ [list 1 item] │
│ default-run │ nu │
│ description │ A new type of shell │
│ documentation │ https://www.nushell.sh/book/ │
│ edition │ 2018 │
│ exclude │ [list 1 item] │
│ homepage │ https://www.nushell.sh │
│ license │ MIT │
│ metadata │ {record 1 field} │
│ name │ nu │
│ repository │ https://github.com/nushell/nushell │
│ rust-version │ 1.60 │
│ version │ 0.72.0 │
╰───────────────┴────────────────────────────────────╯
And if needed we can drill down further:
> open Cargo.toml | get package.version
0.72.0
Plugins
Nu supports plugins that offer additional functionality to the shell and follow the same structured data model that built-in commands use. There are a few examples in the crates/nu_plugins_* directories.
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, making 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.
The awesome-nu repo lists a variety of nu-plugins while the showcase repo shows off informative blog posts that have been written about Nushell along with videos that highlight technical topics that have been presented.
Goals
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 work across platforms and Nu has first-class support for Windows, macOS, and Linux.
-
Nu ensures compatibility with existing platform-specific executables.
-
Nu's workflow and tools should have the usability expected of modern software in 2022 (and beyond).
-
Nu views data as either structured or unstructured. It is a structured shell like PowerShell.
-
Finally, Nu views data functionally. Rather than using mutation, pipelines act as a means to load, change, and save data without mutable state.
Officially Supported By
Please submit an issue or PR to be added to this list.
Contributing
See Contributing for details. Thanks to all the people who already contributed!
License
The project is made available under the MIT license. See the LICENSE file for more information.