### Rustup Installation Options

Source: https://www.nushell.sh/book/installation.html

Example output from rustup showing default installation options for the Rust toolchain. Press '1' to proceed with the default installation.

```shell
Current installation options:

default host triple: x86_64-unknown-linux-gnu
default toolchain: stable
profile: default
modify PATH variable: yes

1) Proceed with installation (default)
2) Customize installation
3) Cancel installation
```

--------------------------------

### Install Plugin from Local Repository

Source: https://www.nushell.sh/book/plugins.html

Install a plugin by providing the path to its local repository. This is useful when developing or installing plugins not yet published.

```bash
cargo install --path . --locked
```

--------------------------------

### Install Nu with Winget (User Scope)

Source: https://www.nushell.sh/book/installation.html

Install Nushell for the current user on a Windows machine using Winget.

```shell
winget install nushell
```

--------------------------------

### Install Nu with Winget (Machine Scope)

Source: https://www.nushell.sh/book/installation.html

Install Nushell for all users on a Windows machine using Winget.

```shell
winget install nushell --scope machine
```

--------------------------------

### Iterate and Change Directory within a Block

Source: https://www.nushell.sh/book/thinking_in_nu.html

This example demonstrates how to iterate through subdirectories, change into each one, and execute a command. Environment changes like `cd` are scoped to the block, ensuring each iteration starts from the correct directory.

```nushell
ls | each { |row|
  cd $row.name
  make
}
```

--------------------------------

### List Installed Plugins

Source: https://www.nushell.sh/book/plugins.html

Display a list of all plugins currently installed and recognized by Nushell.

```bash
plugin list
```

--------------------------------

### Example XDG_CONFIG_HOME Setting

Source: https://www.nushell.sh/book/configuration.html

Illustrates the correct way to set the $env.XDG_CONFIG_HOME environment variable for Nushell.

```nushell
/users/username/dotfiles
```

--------------------------------

### Install Plugin from Crates.io

Source: https://www.nushell.sh/book/plugins.html

Use this command to install a plugin published on crates.io. Ensure the plugin name follows the `nu_plugin_<plugin_name>` convention.

```bash
cargo install nu_plugin_<plugin_name> --locked
```

--------------------------------

### Install Nu with Scoop

Source: https://www.nushell.sh/book/installation.html

Install Nushell on Windows using the Scoop package manager.

```shell
scoop install nu
```

--------------------------------

### Install All Default Core Plugins using Cargo

Source: https://www.nushell.sh/book/plugins.html

Install all default Nushell core plugins using Cargo. This command iterates through a list of plugin names and installs them individually.

```nushell
[
  nu_plugin_inc
  nu_plugin_polars
  nu_plugin_gstat
  nu_plugin_formats
  nu_plugin_query
] | each { cargo install $in --locked } | ignore
```

--------------------------------

### Send executehostcommand event

Source: https://www.nushell.sh/book/line_editor.html

Example of configuring a 'send' event for 'executehostcommand', including the command to be executed.

```yaml
    ...      event: {        send: executehostcommand        cmd: "cd ~"      }    ...
```

--------------------------------

### Sourcing a File from Default Config Directory

Source: https://www.nushell.sh/book/configuration.html

Example of sourcing a file using the $nu.default-config-dir constant, which is known at parse-time.

```nushell
source ($nu.default-config-dir | path join "myfile.nu")
```

--------------------------------

### List All Commands from Installed Plugins

Source: https://www.nushell.sh/book/plugins.html

Use this command to see all available commands provided by installed plugins. Filter by type 'plugin' to specifically list plugin commands.

```nushell
scope commands | where type == "plugin"
```

--------------------------------

### Import and use a simple module

Source: https://www.nushell.sh/book/modules/creating_modules.html

Import all definitions from a module using 'use <module.nu> *' and then use the exported commands. This example imports and uses the 'increment' command.

```nu
use inc.nu *
5 | increment
# => 6
```

--------------------------------

### Install Nu with npm

Source: https://www.nushell.sh/book/installation.html

Install Nushell globally using npm. Note that Nu plugins are not included with this installation method.

```shell
npm install -g nushell
```

--------------------------------

### Install Build Dependencies for Debian/Ubuntu

Source: https://www.nushell.sh/book/installation.html

Install necessary packages for building Nushell on Debian or Ubuntu systems.

```shell
apt install pkg-config libssl-dev build-essential
```

--------------------------------

### Add Nushell APT Repository and Install

Source: https://www.nushell.sh/book/installation.html

Configure the APT package manager for Debian/Ubuntu systems to include the Nushell repository and install Nushell.

```shell
wget -qO- https://apt.fury.io/nushell/gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/fury-nushell.gpg
echo "deb [signed-by=/etc/apt/keyrings/fury-nushell.gpg] https://apt.fury.io/nushell/ /" | sudo tee /etc/apt/sources.list.d/fury-nushell.list
sudo apt update
sudo apt install nushell
```

--------------------------------

### List Available Table Border Modes

Source: https://www.nushell.sh/book/coloring_and_theming.html

List the available options for the `$env.config.table.mode` setting. The output is paginated, and this example shows how to view the first 5 options.

```nu
table --list | first 5
```

--------------------------------

### Initialize oh-my-posh Prompt in Nushell

Source: https://www.nushell.sh/book/3rdpartyprompts.html

Generates the .oh-my-posh.nu configuration file. Ensure oh-my-posh is installed and a theme is specified using the --config flag if not using the default.

```nu
# Generate the .oh-my-posh.nu file
oh-my-posh init nu --config ~/.poshthemes/M365Princess.omp.json

# Initialize oh-my-posh.nu at shell startup by adding this line in your config.nu file
source ~/.oh-my-posh.nu
```

--------------------------------

### Add Nushell DNF Repository and Install

Source: https://www.nushell.sh/book/installation.html

Configure the DNF package manager for RedHat/Fedora/Rocky Linux systems to include the Nushell repository and install Nushell.

```shell
echo "[gemfury-nushell]
name=Gemfury Nushell Repo
baseurl=https://yum.fury.io/nushell/
enabled=1
gpgcheck=0
gpgkey=https://yum.fury.io/nushell/gpg.key" | sudo tee /etc/yum.repos.d/fury-nushell.repo
sudo dnf install -y nushell
```

--------------------------------

### Run Nushell REPL

Source: https://www.nushell.sh/book/configuration.html

Starts the Nushell interactive REPL. By default, it loads the standard library and user configuration files.

```bash
nu
```

--------------------------------

### Set Buffer Editor to VS Code

Source: https://www.nushell.sh/book/configuration.html

A specific example of setting the `buffer_editor` configuration to use Visual Studio Code.

```nu
$env.config.buffer_editor = 'code'
```

--------------------------------

### History Menu Quick Selection Example

Source: https://www.nushell.sh/book/line_editor.html

Demonstrates how to use quick selection within the history menu by typing '!<number>' to directly select an entry without scrolling. This example shows selecting the fourth entry (index 3).

```nushell
!3
```

--------------------------------

### Launch Nu

Source: https://www.nushell.sh/book/installation.html

After installation, launch the Nushell interactive shell by typing 'nu'.

```shell
$ nu
/home/sophiajt/Source>
```

--------------------------------

### Date and Time Formatting

Source: https://www.nushell.sh/book/types_of_data.html

Demonstrates how to get the current date and time and format it as a Unix epoch timestamp. Requires the `date` command.

```nushell
date now
# => Mon, 12 Aug 2024 13:59:22 -0400 (now)
# Format as Unix epoch
date now | format date '%s'
# => 1723485562
```

--------------------------------

### String Interpolation Example

Source: https://www.nushell.sh/book/types_of_data.html

Illustrates how to create strings using variables with string interpolation. Multiple quote styles are supported.

```nushell
let audience: string = "World"
$"Hello, ($audience)"
# => Hello, World
```

--------------------------------

### Python eval() example

Source: https://www.nushell.sh/book/how_nushell_code_gets_run.html

Demonstrates how Python's eval() function parses and evaluates strings, adding a 'meta' step to the execution process.

```python
print("Hello, World!")
eval("print('Hello, Eval!')")
```

--------------------------------

### Boolean Comparison Example

Source: https://www.nushell.sh/book/types_of_data.html

Shows how boolean values are generated through comparisons and used in conditional logic. The `$env.HOME | path exists` check demonstrates a common use case.

```nushell
let mybool: bool = (2 > 1)
$mybool
# => true
let mybool: bool = ($env.HOME | path exists)
$mybool
# => true
```

```nushell
let num = -2
if $num < 0 { print "It's negative" }
# => It's negative
```

--------------------------------

### Get User Input: Bash vs Nushell

Source: https://www.nushell.sh/book/coming_from_bash.html

Illustrates how to prompt the user for input and store it in a variable in Bash and Nushell.

```bash
read var
```

```nu
let var = input
```

--------------------------------

### Use a custom command in a pipeline

Source: https://www.nushell.sh/book/custom_commands.html

This example shows how to pipe a list of numbers into the custom `double` command and observe the doubled output.

```nushell
[1 2 3] | double
```

--------------------------------

### Send menu event with completion_menu

Source: https://www.nushell.sh/book/line_editor.html

Example of configuring a 'send' event for the 'menu' type, specifically activating the 'completion_menu'.

```yaml
    ...      event: {        send: menu        name: completion_menu      }    ...
```

--------------------------------

### Check Binary Data Signature

Source: https://www.nushell.sh/book/types_of_data.html

Verifies the initial bytes of a binary file against a known signature. This example checks if a JPEG file starts with `0xffd8`.

```nushell
open nushell_logo.jpg
| into binary
| first 2
| $in == 0x[ff d8]
```

--------------------------------

### Compare Startup Time with and without Standard Library

Source: https://www.nushell.sh/book/standard_library.html

Demonstrates the difference in startup time when the standard library is disabled versus when it is enabled. Useful for performance analysis.

```bash
nu --no-std-lib -n -c "$nu.startup-time"
# => 1ms 125µs 10ns
```

```bash
nu -n -c "$nu.startup-time"
# => 4ms 889µs 576ns
```

--------------------------------

### Fastest REPL Startup

Source: https://www.nushell.sh/book/configuration.html

Enters the Nushell REPL with minimal startup overhead by disabling the standard library and configuration file loading. This is the fastest way to start the REPL.

```bash
nu -n --no-std-lib
```

--------------------------------

### Install Nushell using Cargo

Source: https://www.nushell.sh/book/installation.html

Installs the latest Nushell release from crates.io using Cargo. Ensure you have Rust and Cargo installed. Default plugins may need separate installation.

```bash
cargo install nu --locked
```

--------------------------------

### Integer Division Example

Source: https://www.nushell.sh/book/types_of_data.html

Demonstrates basic integer arithmetic and type checking. The result of integer division is an integer.

```nushell
10 / 2
# => 5
5 | describe
# => int
```

--------------------------------

### Create directories

Source: https://www.nushell.sh/book/coming_from_cmd.html

Make new directories.

```nushell
mkdir
```

--------------------------------

### Documenting a Nushell module

Source: https://www.nushell.sh/book/modules/creating_modules.html

Example of how to add documentation to a Nushell module. Documentation is added as commented lines at the beginning of the module file.

```nushell
# This module provides utility functions for common tasks.
# It includes commands for incrementing numbers and converting ranges to lists.
```

--------------------------------

### Apply and Preview Table Border Modes

Source: https://www.nushell.sh/book/coloring_and_theming.html

Demonstrates setting the table border mode to 'rounded' and then to 'psql', showing the first 5 available modes for each setting.

```nu
$env.config.table.mode = 'rounded'
table --list | first 5
```

```nu
$env.config.table.mode = 'psql'
table --list | first 5
```

--------------------------------

### Get specific column values with `get`

Source: https://www.nushell.sh/book/working_with_tables.html

Use `get` to extract values from a specific column as a list. This is useful when you only need the data within the cells, not the entire column structure.

```nushell
ls | get name
```

--------------------------------

### Define and Call a Function in a Nushell Script

Source: https://www.nushell.sh/book/scripts.html

Example of a Nushell script defining a function `greet` and then calling it. Definitions can appear anywhere in the script.

```nushell
# myscript.nu
def greet [name] {
  ["hello" $name]
}

greet "world"

```

--------------------------------

### View Configuration Documentation

Source: https://www.nushell.sh/book/configuration.html

Displays detailed documentation for Nushell configuration options, piped to `less` for easier viewing. Requires `nu-highlight` for colored output.

```nu
config nu --doc | nu-highlight | less -R
```

--------------------------------

### Apply nullify command to ls output

Source: https://www.nushell.sh/book/custom_commands.html

This example pipes the output of the `ls` command into the `nullify` command to set the 'name' and 'size' columns to null.

```nushell
ls | nullify name size
```

--------------------------------

### Demonstrate Recursion Error

Source: https://www.nushell.sh/book/aliases.html

This example shows a common mistake that leads to a recursion error when attempting to redefine a command without backing it up first.

```nushell
def ls [] { ls }; ls    # Do *NOT* do this! This will throw a recursion error

```

--------------------------------

### Custom Command with Rest Parameters

Source: https://www.nushell.sh/book/cheat_sheet.html

Defines a custom command `greet` that accepts any number of string arguments using rest parameters. It then prints each argument.

```nushell
def greet [...name: string] {
    print "hello all:"
    for $n in $name {
        print $n
    }
}
greet earth mars jupiter venus
```

--------------------------------

### Creating a Directory with Dynamic Name (Pipeline)

Source: https://www.nushell.sh/book/pipelines.html

Demonstrates an alternative, more verbose but potentially more readable, method of creating a directory with a dynamic name using a step-by-step pipeline. Each step's output is piped to the next.

```nushell
date now                    # 1: today
| $in + 1day                # 2: tomorrow
| format date '%F'          # 3: Format as YYYY-MM-DD
| $'($in) Report'           # 4: Format the directory name
| mkdir $in                 # 5: Create the directory
```

--------------------------------

### Install Build Dependencies for RHEL-based Distros

Source: https://www.nushell.sh/book/installation.html

Install necessary packages for building Nushell on RHEL, Fedora, or Rocky Linux systems.

```shell
yum install libxcb openssl-devel libX11-devel
```

--------------------------------

### Identify Inefficient Standard Library Usage in Startup Files

Source: https://www.nushell.sh/book/standard_library.html

This command helps identify files in your startup configuration that might be using inefficient syntax for importing standard library modules. Review and update these files to recommended syntax.

```nushell
view files
| enumerate
| flatten
| where filename !~ '^std'
| where filename !~ '^entry'
| where {|file| (view span $file.start $file.end) =~ 'use\W+std[^\/]' }
```

--------------------------------

### Install Build Dependencies for macOS using Homebrew

Source: https://www.nushell.sh/book/installation.html

Install required dependencies 'openssl' and 'cmake' using Homebrew on macOS for building Nushell.

```shell
brew install openssl cmake
```

--------------------------------

### Creating a Directory with Dynamic Name (Subexpression)

Source: https://www.nushell.sh/book/pipelines.html

An example of creating a directory using a subexpression to dynamically generate part of the directory name based on the current date.

```nushell
mkdir $'((date now) + 1day | format date '%F') Report'
```

--------------------------------

### Add Nushell APK Repository and Install

Source: https://www.nushell.sh/book/installation.html

Configure the APK package manager for Alpine Linux to include the Nushell repository and install Nushell.

```shell
echo "https://alpine.fury.io/nushell/" | tee -a /etc/apk/repositories
apc update
apk add --allow-untrusted nushell
```

--------------------------------

### Call 'greet' command with two arguments

Source: https://www.nushell.sh/book/custom_commands.html

This demonstrates calling the 'greet' command with two required positional arguments, 'Wei' and 'Mei', resulting in a formatted greeting.

```nushell
greet Wei Mei
```

--------------------------------

### Import a module and its definitions

Source: https://www.nushell.sh/book/modules/using_modules.html

Use the `use` command to import functionality from a module. The standard library is readily available.

```nushell
use <path/to/module> <members...>
```

```nushell
use std/log
log info "Hello, Modules"
```

--------------------------------

### Get Secret Input: Bash vs Nushell

Source: https://www.nushell.sh/book/coming_from_bash.html

Shows how to securely get secret input from the user without echoing keystrokes in Bash and Nushell.

```bash
read -s secret
```

```nu
let secret = input -s
```

--------------------------------

### Multi-line Command Formatting Examples

Source: https://www.nushell.sh/book/style_guide.html

Demonstrates correct usage of multi-line formatting for pipelines, lists, records, and closures. It's recommended for scripts and complex commands exceeding 80 characters or containing nested structures.

```nushell
[[status]; [UP] [UP]] | all {|el|
    $el.status == UP
}

[1 2 3 4] | reduce {|elt, acc|
    $elt + $acc
}

{x: 1, y: 2}

[
  {name: "Teresa", age: 24},
  {name: "Thomas", age: 26}
]

let selectedProfile = (for it in ($credentials | transpose name credentials) {
    echo $it.name
})
```

```nushell
[[status]; [UP] [UP]] | all { |el| 
    # too few "\n" before "}": one "\n" is required
    $el.status == UP}

# too many spaces before "2": one space is required (like in one-line format)
[1  2 3 4] | reduce {|elt, acc|
    $elt + $acc
}

{
   # too many "\n" before "x": one-line format required as no nested lists or record exist
   x: 1,
   y: 2
}

# too few "\n" before "{": multi-line format required as there are two nested records
[{name: "Teresa", age: 24},
  {name: "Thomas", age: 26}]

let selectedProfile = (
    # too many "\n" before "foo": no "\n" is allowed
    for it in ($credentials | transpose name credentials) {
        echo $it.name
})
```

--------------------------------

### NUON Data Structure Example

Source: https://www.nushell.sh/book/loading_data.html

This example shows a NUON data structure, which is a superset of JSON and allows for comments and optional commas, making it more human-friendly.

```nushell
{
  menus: [
    # Configuration for default nushell menus
    # Note the lack of source parameter
    {
      name: completion_menu
      only_buffer_difference: false
      marker: "| "
      type: {
          layout: columnar
          columns: 4
          col_width: 20   # Optional value. If missing all the screen width is used to calculate column width
          col_padding: 2
      }
      style: {
          text: green
          selected_text: green_reverse
          description_text: yellow
      }
    }
  ]
}
```

--------------------------------

### Define 'greet' command with multiple parameters (spaces)

Source: https://www.nushell.sh/book/custom_commands.html

This defines a 'greet' command that accepts two required positional parameters, 'name1' and 'name2', separated by spaces in the parameter list.

```nushell
def greet [name1 name2] {
  $"Hello, ($name1) and ($name2)!"
}
```

--------------------------------

### Configure Completion Options

Source: https://www.nushell.sh/book/custom_completions.html

Demonstrates how to configure custom completion behavior, such as case sensitivity, sorting, and matching algorithm, by returning a record from the completer command.

```nushell
def animals [] {
    {
        options: {
            case_sensitive: false,
            completion_algorithm: substring,
            sort: false,
        },
        completions: [cat, rat, bat]
    }
}
def my-command [animal: string@animals] { print $animal }
```

--------------------------------

### Until event with menu and menunext

Source: https://www.nushell.sh/book/line_editor.html

Configures a keybinding to first try opening a completion menu, and if pressed again while the menu is active, move to the next item.

```nushell
$env.config.keybindings ++= [{
    name: completion_menu
    modifier: control
    keycode: char_t
    mode: emacs
    event: {
        until: [
          { send: menu name: completion_menu }
          { send: menunext }
        ]
    }
}]
```

--------------------------------

### Example of Invalid Shell Error

Source: https://www.nushell.sh/book/default_shell.html

This is an example of an error message you might encounter if Nu is not listed in the '/etc/shells' file when trying to change your login shell using 'chsh'.

```text
chsh: /home/username/.cargo/bin/nu is an invalid shell
```

--------------------------------

### Get List Item Using a Variable Index

Source: https://www.nushell.sh/book/working_with_lists.html

Use the `get` command to retrieve a list item when the index is stored in a variable. This provides dynamic access to list elements.

```nushell
let names = [Mark Tami Amanda Jeremy]
let index = 1
$names | get $index # gives Tami
```

--------------------------------

### Access record keys with spaces using get

Source: https://www.nushell.sh/book/navigating_structured_data.html

Alternatively, use the `get` command with the quoted key name to access record values, especially useful for keys with spaces.

```nushell
let record_example = {
    "key x":12
    "key y":4
  }
$record_example | get "key x"
```

--------------------------------

### Viewing module help

Source: https://www.nushell.sh/book/modules/creating_modules.html

After importing a module with `use`, you can view its exported commands and descriptions using the `help` command.

```nushell
use my-utils *
help my-utils
```

--------------------------------

### Import and Use Renamed Submodule Commands

Source: https://www.nushell.sh/book/modules/creating_modules.html

Imports all definitions from `my-utils` and demonstrates that the `go home` command is now available, while the direct `home` command is not, due to the submodule export structure.

```nushell
use my-utils *
# => As expected:
go home
# => works
home
# => Error: command not found
```

--------------------------------

### Using `get` to Access a Table Row

Source: https://www.nushell.sh/book/navigating_structured_data.html

Demonstrates using the `get` command with a row index (1) to retrieve a specific row from the table. This is an alternative to direct cell-path access.

```nushell
$data | get 1
```

--------------------------------

### Get Specific Value from JSON

Source: https://www.nushell.sh/book/loading_data.html

After opening a JSON file, use the 'get' command to extract a specific field's value. Requires the file to be parsed into a table first.

```nushell
open editors/vscode/package.json | get version
```

--------------------------------

### View All Commands

Source: https://www.nushell.sh/book/quick_tour.html

Use `help commands` to view a table of all available commands (excluding externals). This output can be piped to other commands for further processing.

```nushell
help commands
```

--------------------------------

### Example of History Menu Search Result

Source: https://www.nushell.sh/book/line_editor.html

After filtering and selecting an entry from the history menu, the typed words are replaced by the selected command. This example shows a more complex command that might be selected.

```nushell
let a = (ls | where size > 10MiB)
```

--------------------------------

### Define a simple custom command

Source: https://www.nushell.sh/book/custom_commands.html

Defines a basic custom command named `greet` that takes one argument and returns a formatted string. This is useful for encapsulating reusable logic.

```nushell
def greet [name] {
  $"Hello, ($name)!"
}
```

--------------------------------

### Example of History Menu Search Input

Source: https://www.nushell.sh/book/line_editor.html

When the history menu is activated, any text typed will filter the history. This example shows a simple variable assignment that could be part of a command in history.

```nushell
let a = ()
```

--------------------------------

### Fetch GitHub Contributors using http get and select (Nushell)

Source: https://www.nushell.sh/book/thinking_in_nu.html

Nushell's built-in http get command and native JSON handling simplify fetching and selecting data from APIs, eliminating the need for external tools like curl and jq.

```nushell
http get https://api.github.com/repos/nushell/nushell/contributors | select login contributions
```

--------------------------------

### Define 'greet' command with multiple parameters (linebreaks)

Source: https://www.nushell.sh/book/custom_commands.html

This defines a 'greet' command that accepts two required positional parameters, 'name1' and 'name2', separated by linebreaks in the parameter list.

```nushell
def greet [
  name1
  name2
] {
  $"Hello, ($name1) and ($name2)!"
}
```

--------------------------------

### Import Plugin by Name

Source: https://www.nushell.sh/book/plugins.html

Use this command to immediately load a registered plugin into the current Nushell session. The plugin name is used without the `nu_plugin` prefix.

```bash
plugin use cool
```

--------------------------------

### Get the current date

Source: https://www.nushell.sh/book/coming_from_cmd.html

Retrieve the current date and time.

```nushell
date now
```

--------------------------------

### Basic Pipeline: Open, Update, Save

Source: https://www.nushell.sh/book/pipelines.html

Demonstrates a typical pipeline flow: opening a file, updating a specific field, and saving the result to a new file. This is useful for configuration file manipulation.

```nushell
open Cargo.toml | update workspace.dependencies.base64 0.24.2 | save Cargo_new.toml
```

--------------------------------

### Get help for operators

Source: https://www.nushell.sh/book/quick_tour.html

Accesses the in-shell help documentation for Nushell operators.

```nushell
help operators
```

--------------------------------

### Get help for escapes

Source: https://www.nushell.sh/book/quick_tour.html

Accesses the in-shell help documentation for Nushell escape sequences.

```nushell
help escapes
```

--------------------------------

### View Configuration Documentation

Source: https://www.nushell.sh/book/configuration.html

Displays detailed documentation for Nushell configuration options. This command uses `nu-highlight` and can be piped to a pager like `bat` or `less`.

```nu
config nu --doc | nu-highlight | bat
```

```nu
config nu --doc | nu-highlight | less -R
```

--------------------------------

### Get the current time

Source: https://www.nushell.sh/book/coming_from_cmd.html

Retrieve the current time, formatted to show hours, minutes, and seconds.

```nushell
date now | format date "%H:%M:%S"
```

--------------------------------

### Configure Advanced Color Settings with Hex and Attributes

Source: https://www.nushell.sh/book/coloring_and_theming.html

This example shows how to configure colors using hex codes and attributes like 'bold' (bli). It also demonstrates setting only the foreground color for specific elements.

```nushell
$env.config.color_config.separator = "#88b719" # this sets only the foreground color like PR #486
$env.config.color_config.leading_trailing_space_bg = white # this sets only the foreground color in the original style
$env.config.color_config.header = { # this is like PR #489
    fg: "#B01455", # note, quotes are required on the values with hex colors
    bg: "#ffb900", # note, commas are not required, it could also be all on one line
    attr: bli # note, there are no quotes around this value. it works with or without quotes
}
$env.config.color_config.datetime = "#75507B"
$env.config.color_config.filesize = "#729fcf"
$env.config.color_config.row_index = {
    # note, that this is another way to set only the foreground, no need to specify bg and attr
    fg: "#e50914"
}
```

--------------------------------

### Capture Span Metadata

Source: https://www.nushell.sh/book/creating_errors.html

Use the 'metadata' command to get the span of an argument for error reporting.

```nushell
let span = (metadata $x).span;
```

--------------------------------

### Define Custom Completions with Descriptions and Styles

Source: https://www.nushell.sh/book/custom_completions.html

This example defines a custom completion function that returns records with `value`, `description`, and `style` fields. This allows for richer completion menus with visual cues.

```nushell
def my_commits [] {
    [
        { value: "5c2464", description: "Add .gitignore", style: red },
        # "attr: ub" => underlined and bolded
        { value: "f3a377", description: "Initial commit", style: { fg: green, bg: "#66078c", attr: ub } }
    ]
}
```

--------------------------------

### Create a New Overlay Verbose

Source: https://www.nushell.sh/book/overlays.html

Uses the `overlay new` command as a shortcut to create a new overlay named 'scratchpad'. Custom definitions are then added to this new overlay.

```nushell
(zero)> overlay use spam

(spam)> overlay new scratchpad

(scratchpad)> def eggs [] { "eggs" }
```

--------------------------------

### Get help for a command

Source: https://www.nushell.sh/book/quick_tour.html

Shows how to access the in-shell help system for a specific command like `ls`.

```nushell
help ls
```

--------------------------------

### Define 'greet' command with multiple parameters (commas)

Source: https://www.nushell.sh/book/custom_commands.html

This defines a 'greet' command that accepts two required positional parameters, 'name1' and 'name2', separated by commas in the parameter list.

```nushell
def greet [name1, name2] {
  $"Hello, ($name1) and ($name2)!"
}
```

--------------------------------

### Get Command Help (Nushell)

Source: https://www.nushell.sh/book/coming_from_bash.html

Retrieves help information for a specific command or lists/searches available commands.

```nushell
help <command>
```

```nushell
help commands
```

```nushell
help --find <string>
```

--------------------------------

### Nushell Static Parsing Example

Source: https://www.nushell.sh/book/thinking_in_nu.html

Shows a scenario where dynamically generating source code and then sourcing it fails due to Nushell's static parsing, resulting in a file not found error.

```nushell
("print Hello" | save output.nu;
source output.nu)
```

--------------------------------

### Single-quoted string example

Source: https://www.nushell.sh/book/working_with_strings.html

Use single-quoted strings for simple text literals. They do not interpret escape characters.

```nushell
'hello world'
# => hello world
'The
end'
# => The
# => end
```

--------------------------------

### Float Division Example

Source: https://www.nushell.sh/book/types_of_data.html

Shows division with floating-point numbers. Note that decimal values in Nushell are approximate.

```nushell
2.5 / 5.0
# => 0.5
```

```nushell
10.2 * 5.1
# => 52.01999999999999
```

--------------------------------

### Hello, World! in Nushell

Source: https://www.nushell.sh/book/how_nushell_code_gets_run.html

A basic Nushell program that prints 'Hello, World!'. Run using `nu hello.nu`.

```nushell
# hello.nu

print "Hello, World!"
```

--------------------------------

### Edit event: insertstring

Source: https://www.nushell.sh/book/line_editor.html

Example of configuring an 'edit' event to insert a string at the current prompt location.

```yaml
    ...      event: {        edit: insertstring        value: "MY NEW STRING"      }    ...
```

--------------------------------

### Using a let variable with source

Source: https://www.nushell.sh/book/how_nushell_code_gets_run.html

Demonstrates how a 'let' variable can be used with the 'source' command. This is evaluated at runtime.

```nushell
let my_path = "~/nushell-files"
source $"($my_path)/common.nu"
```

--------------------------------

### Get List Length

Source: https://www.nushell.sh/book/working_with_lists.html

Determine the number of items in a list using the `length` command. This is useful for iteration or validation.

```nushell
[red green blue] | length
```

--------------------------------

### Call a greeting command with a named flag

Source: https://www.nushell.sh/book/custom_commands.html

Demonstrates calling the `greet` command with both a positional parameter and an optional named flag. Shows examples where the flag is provided and where it is omitted.

```nushell
greet Lucia --age 23
# => ╭──────┬───────╮
# => │ name │ Lucia │
# => │ age  │ 23    │
# => ╰──────┴───────╯

greet --age 39 Ali
# => ╭──────┬─────╮
# => │ name │ Ali │
# => │ age  │ 39  │
# => ╰──────┴─────╯

greet World
# => ╭──────┬───────╮
# => │ name │ World │
# => │ age  │       │
```

--------------------------------

### Get DataFrame Schema

Source: https://www.nushell.sh/book/dataframes.html

Retrieves and displays the schema of a DataFrame, including column names and their inferred data types.

```nushell
$df_0 | polars schema
# => ╭───────────┬─────╮
# => │ anzsic06  │ str │
# => │ Area      │ str │
# => │ year      │ i64 │
# => │ geo_count │ i64 │
# => │ ec_count  │ i64 │
# => ╰───────────┴─────╯
```

--------------------------------

### Get the present working directory

Source: https://www.nushell.sh/book/coming_from_cmd.html

Access the current working directory path stored in the PWD environment variable.

```nushell
$env.PWD
```

--------------------------------

### Call Command with Rest Parameters

Source: https://www.nushell.sh/book/custom_commands.html

Demonstrates calling the 'multi-greet' command with multiple string arguments, which are processed individually.

```nushell
multi-greet Elin Lars Erik
# => Hello, Elin!
# => Hello, Lars!
# => Hello, Erik!
```

--------------------------------

### Edit event: moverightuntil

Source: https://www.nushell.sh/book/line_editor.html

Example of configuring an 'edit' event to move the cursor right until a specific character is found.

```yaml
    ...      event: {        edit: moverightuntil        value: "S"      }    ...
```

--------------------------------

### Parameterize Nushell Script with `main`

Source: https://www.nushell.sh/book/scripts.html

Demonstrates using a `main` command in a Nushell script to accept positional parameters. Arguments are passed after the script name.

```nushell
# myscript.nu
def main [x: int] {
  $x + 10
}

```

```bash
nu myscript.nu 100
# => 110
```

--------------------------------

### Custom Command with Switch Flag and Shorthand

Source: https://www.nushell.sh/book/cheat_sheet.html

Defines a custom command `greet` with a required string `name`, an optional integer flag `--age` (shorthand `-a`), and a boolean switch flag `--twice`. The output depends on whether `--twice` is used.

```nushell
def greet [
    name: string
    --age (-a): int
    --twice
] {
    if $twice {
        [$name $age $name $age]
    } else {
        [$name $age]
    }
}
greet -a 10 --twice hello
```

--------------------------------

### Nushell variable name restrictions

Source: https://www.nushell.sh/book/variables

Illustrates that variable names starting with '$' are allowed in Nushell and are equivalent to names without the '$'.

```nushell
let $var = 42
# identical to `let var = 42`

```

--------------------------------

### Sequential REPL Commands

Source: https://www.nushell.sh/book/how_nushell_code_gets_run.html

Shows how commands executed in separate REPL entries work due to environment merging between cycles.

```nushell
> cd spam
> source-env foo.nu
```

--------------------------------

### Interact with Context-Aware Completions

Source: https://www.nushell.sh/book/custom_completions.html

Demonstrates the interactive usage of the context-aware custom completion defined previously. Shows how tab completion provides relevant suggestions based on previous input.

```nushell
>| my-command
cat                 dog                 eel
```

```nushell
>| my-command dog
Lulu                Enzo
```

```nushell
>my-command dog enzo
The dog is named Enzo
```

--------------------------------

### Call a greeting command with a default value

Source: https://www.nushell.sh/book/custom_commands.html

Demonstrates calling the `greet` command with a default parameter value. The first call uses the default, while the second overrides it.

```nushell
greet
# => Hello, Nushell!

greet world
# => Hello, World!
```

--------------------------------

### Create a Range of Numbers

Source: https://www.nushell.sh/book/types_of_data.html

Generates a sequence of numbers from a start to an end value. Supports an optional stride for custom increments.

```nushell
1..5
```

--------------------------------

### Hello, World! in Rust

Source: https://www.nushell.sh/book/how_nushell_code_gets_run.html

A simple 'Hello, World!' program in Rust. Requires compilation using `rustc main.rs` and execution of the binary.

```rust
// main.rs

fn main() {
    println!("Hello, World!");
}
```

--------------------------------

### Custom Command with String Parameter

Source: https://www.nushell.sh/book/cheat_sheet.html

Defines a custom command named `greet` that accepts a single string argument `name`. The command returns a greeting string.

```nushell
def greet [name: string] {
    $"hello ($name)"
}
```

--------------------------------

### Get Unique Values from a Series using `unique`

Source: https://www.nushell.sh/book/dataframes.html

Use `polars unique` on a Series to retrieve only the unique values present in that column.

```nushell
$df_1 | polars get first | polars unique
```

--------------------------------

### Get original index with enumerate and select

Source: https://www.nushell.sh/book/navigating_structured_data.html

To retain the original row index when using `select`, pipe the data through `enumerate` first.

```nushell
$data | enumerate | select 1
```

--------------------------------

### Demonstrate Overlay Precedence

Source: https://www.nushell.sh/book/overlays.html

Shows how defining a function in one overlay and then using another overlay that redefines it results in the latter's definition being used. Re-using an overlay brings it to the top of the stack.

```nushell
(zero)> def foo [] { "foo-in-zero" }

(zero)> overlay use spam

(spam)> foo
foo

(spam)> overlay use zero

(zero)> foo
foo-in-zero

(zero)> overlay list
───┬──────
 0 │ spam
 1 │ zero
───┴──────
```