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Change help commands to use name from scope instead of the name from the declaration (#14490)
# Description

Before this PR, `help commands` uses the name from a command's
declaration rather than the name in the scope. This is problematic when
trying to view the help page for the `main` command of a module. For
example, `std bench`:

```nushell
use std/bench
help bench
# => Error: nu::parser::not_found
# => 
# =>   × Not found.
# =>    ╭─[entry #10:1:6]
# =>  1 │ help bench
# =>    ·      ──┬──
# =>    ·        ╰── did not find anything under this name
# =>    ╰────
```

This can also cause confusion when importing specific commands from
modules. Furthermore, if there are multiple commands with the same name
from different modules, the help text for _both_ will appear when
querying their help text (this is especially problematic for `main`
commands, see #14033):

```nushell
use std/iter
help iter find
# => Error: nu::parser::not_found
# => 
# =>   × Not found.
# =>    ╭─[entry #3:1:6]
# =>  1│ help iter find
# =>    ·      ────┬────
# =>    ·          ╰── did not find anything under this name
# =>    ╰────
help find
# => Searches terms in the input.
# => 
# => Search terms: filter, regex, search, condition
# => 
# => Usage:
# =>   > find {flags} ...(rest) 
# [...]
# => Returns the first element of the list that matches the
# => closure predicate, `null` otherwise
# [...]
# (full text omitted for brevity)
```

This PR changes `help commands` to use the name as it is in scope, so
prefixing any command in scope with `help` will show the correct help
text.


```nushell
use std/bench
help bench
# [help text for std bench]
use std/iter
help iter find
# [help text for std iter find]

use std
help std bench
# [help text for std bench]
help std iter find
# [help text for std iter find]
```

Additionally, the IR code generation for commands called with the
`--help` text has been updated to reflect this change.

This does have one side effect: when a module has a `main` command
defined, running `help <name>` (which checks `help aliases`, then `help
commands`, then `help modules`) will show the help text for the `main`
command rather than the module. The help text for the module is still
accessible with `help modules <name>`.

Fixes #10499, #10311, #11609, #13470, #14033, and #14402.
Partially fixes #10707.
Does **not** fix #11447.

# User-Facing Changes

* Help text for commands can be obtained by running `help <command
name>`, where the command name is the same thing you would type in order
to execute the command. Previously, it was the name of the function as
written in the source file.
  * For example, for the following module `spam` with command `meow`:
    ```nushell
    module spam { 
        # help text
        export def meow [] {}
    }
    ```
    * Before this PR:
* Regardless of how `meow` is `use`d, the help text is viewable by
running `help meow`.
    * After this PR:
* When imported with `use spam`: The `meow` command is executed by
running `spam meow` and the `help` text is viewable by running `help
spam meow`.
* When imported with `use spam foo`: The `meow` command is executed by
running `meow` and the `help` text is viewable by running `meow`.
* When a module has a `main` command defined, `help <module name>` will
return help for the main command, rather than the module. To access the
help for the module, use `help modules <module name>`.

# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting
N/A
2024-12-10 09:27:30 -06:00
.cargo optimize aarch64 when able (#10433) 2023-09-21 03:57:07 +12:00
.githooks Add git hooks for formatting and running clippy (#8820) 2023-04-13 07:34:23 -05:00
.github Bump crate-ci/typos from 1.28.1 to 1.28.2 (#14503) 2024-12-04 09:37:19 +08:00
assets REFACTOR: clean the root of the repo (#9231) 2023-05-20 07:57:51 -05:00
benches Remove the NU_DISABLE_IR option (#14293) 2024-11-15 12:09:25 +08:00
crates Change help commands to use name from scope instead of the name from the declaration (#14490) 2024-12-10 09:27:30 -06:00
devdocs Remove dataframes crate and feature (#12889) 2024-05-20 17:22:08 +00:00
docker Tests for new Alpine and Debian image builds (#14225) 2024-11-01 07:45:20 +08:00
scripts chore: Add nu_plugin_polars to build and install scripts (#13550) 2024-08-06 15:23:56 -05:00
src Use const NU_LIB_DIRS in startup (#14549) 2024-12-10 06:36:05 -06:00
tests Use const NU_LIB_DIRS in startup (#14549) 2024-12-10 06:36:05 -06:00
wix change wix install method from perMachine to perUser (#12720) 2024-05-01 17:31:16 -05:00
.gitattributes Add Nushell Language detect for linguist (#9491) 2023-06-21 15:30:10 +08:00
.gitignore Add custom datetime format through strftime strings (#9500) 2023-06-23 15:05:04 -05:00
Cargo.lock update to reedline 9eb3c2d (#14541) 2024-12-08 08:43:36 -06:00
Cargo.toml Update roxmltree from 0.19 to 0.20, the latest version (#14513) 2024-12-04 21:39:45 +01:00
CITATION.cff Create CITATION.cff (#12983) 2024-06-06 08:53:34 +08:00
CODE_OF_CONDUCT.md First pass at updating all documentation formatting and cleaning up output of examples (#2031) 2020-06-24 06:21:47 +12:00
CONTRIBUTING.md Remove dataframes crate and feature (#12889) 2024-05-20 17:22:08 +00:00
Cross.toml Fix cross-compiling with cross-rs (#9972) 2023-08-09 22:08:35 -07:00
LICENSE Update LICENSE 2023-04-03 08:23:19 +12:00
README.md fix: sample_config (#14465) 2024-11-29 08:06:14 -06:00
rust-toolchain.toml udpate rust toolchain to rust 1.81.0 (#14473) 2024-11-29 21:46:58 +01:00
SECURITY.md Links to security contacts (#13488) 2024-07-30 17:05:56 +02:00
toolkit.nu Start to Add WASM Support Again (#14418) 2024-11-30 07:57:11 -06:00
typos.toml Bump typo with new ignore (#13563) 2024-08-08 06:50:28 +08:00

Nushell

Crates.io Build Status Nightly Build Discord The Changelog #363 @nu_shell GitHub commit activity GitHub contributors

A new type of shell.

Example of nushell

Table of Contents

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:

Packaging status

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  │
├───┼───────┼───────────┼───────┼───────────┼───────────┤
│ 02240 │ Slack.exe │ 16.40 │ 178.3 MiB │ 232.6 MiB │
│ 116948 │ Slack.exe │ 16.32 │ 205.0 MiB │ 197.9 MiB │
│ 217700 │ 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.