A new type of shell
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Devyn Cairns bdc32345bd
Move most of the peculiar argument handling for external calls into the parser (#13089)
# Description

We've had a lot of different issues and PRs related to arg handling with
externals since the rewrite of `run-external` in #12921:

- #12950
- #12955
- #13000
- #13001
- #13021
- #13027
- #13028
- #13073

Many of these are caused by the argument handling of external calls and
`run-external` being very special and involving the parser handing
quoted strings over to `run-external` so that it knows whether to expand
tildes and globs and so on. This is really unusual and also makes it
harder to use `run-external`, and also harder to understand it (and
probably is part of the reason why it was rewritten in the first place).

This PR moves a lot more of that work over to the parser, so that by the
time `run-external` gets it, it's dealing with much more normal Nushell
values. In particular:

- Unquoted strings are handled as globs with no expand
- The unescaped-but-quoted handling of strings was removed, and the
parser constructs normal looking strings instead, removing internal
quotes so that `run-external` doesn't have to do it
- Bare word interpolation is now supported and expansion is done in this
case
- Expressions typed as `Glob` containing `Expr::StringInterpolation` now
produce `Value::Glob` instead, with the quoted status from the expr
passed through so we know if it was a bare word
- Bare word interpolation for values typed as `glob` now possible, but
not implemented
- Because expansion is now triggered by `Value::Glob(_, false)` instead
of looking at the expr, externals now support glob types

# User-Facing Changes

- Bare word interpolation works for external command options, and
otherwise embedded in other strings:
  ```nushell
  ^echo --foo=(2 + 2) # prints --foo=4
  ^echo -foo=$"(2 + 2)" # prints -foo=4
  ^echo foo="(2 + 2)" # prints (no interpolation!) foo=(2 + 2)
  ^echo foo,(2 + 2),bar # prints foo,4,bar
  ```

- Bare word interpolation expands for external command head/args:
  ```nushell
  let name = "exa"
  ~/.cargo/bin/($name) # this works, and expands the tilde
  ^$"~/.cargo/bin/($name)" # this doesn't expand the tilde
  ^echo ~/($name)/* # this glob is expanded
  ^echo $"~/($name)/*" # this isn't expanded
  ```

- Ndots are now supported for the head of an external command
(`^.../foo` works)

- Glob values are now supported for head/args of an external command,
and expanded appropriately:
  ```nushell
  ^("~/.cargo/bin/exa" | into glob) # the tilde is expanded
  ^echo ("*.txt" | into glob) # this glob is expanded
  ```

- `run-external` now works more like any other command, without
expecting a special call convention
  for its args:
  ```nushell
  run-external echo "'foo'"
  # before PR: 'foo'
  # after PR:  foo
  run-external echo "*.txt"
  # before PR: (glob is expanded)
  # after PR:  *.txt
  ```

# Tests + Formatting
Lots of tests added and cleaned up. Some tests that weren't active on
Windows changed to use `nu --testbin cococo` so that they can work.
Added a test for Linux only to make sure tilde expansion of commands
works, because changing `HOME` there causes `~` to reliably change.

- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting
- [ ] release notes: make sure to mention the new syntaxes that are
supported
2024-06-19 21:00:03 -07:00
.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 1.22.4 to 1.22.7 (#13176) 2024-06-19 00:59:03 +00:00
assets REFACTOR: clean the root of the repo (#9231) 2023-05-20 07:57:51 -05:00
benches Change the error style during tests to plain (#13061) 2024-06-18 21:37:24 -07:00
crates Move most of the peculiar argument handling for external calls into the parser (#13089) 2024-06-19 21:00:03 -07:00
devdocs Remove dataframes crate and feature (#12889) 2024-05-20 17:22:08 +00:00
docker Fix alpine docker file (#10992) 2023-11-08 06:30:34 -06:00
scripts Remove dataframes crate and feature (#12889) 2024-05-20 17:22:08 +00:00
src Change the error style during tests to plain (#13061) 2024-06-18 21:37:24 -07:00
tests Make which-support feature non-optional (#13125) 2024-06-12 20:04:12 -05:00
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 Bump git2 from 0.18.3 to 0.19.0 (#13179) 2024-06-19 01:09:25 +00:00
Cargo.toml Add derive macros for FromValue and IntoValue to ease the use of Values in Rust code (#13031) 2024-06-17 16:05:11 -07:00
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 Update README.md (#13157) 2024-06-18 07:16:42 -05:00
rust-toolchain.toml Bump our Rust version to stable (#12471) 2024-04-10 23:41:38 +02:00
toolkit.nu Extend functionality of tango benchmark helpers (#13107) 2024-06-09 14:03:52 +03:00
typos.toml Minimize future false positive typos (#12751) 2024-05-04 15:00:44 +00:00

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.