> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/redox-os/redox/llms.txt
> Use this file to discover all available pages before exploring further.

# Ion Shell

> The default shell for Redox OS

## Overview

**Ion** is the default shell for Redox OS, designed to be modern, fast, and safe. Written in Rust, Ion provides a familiar command-line interface with advanced scripting capabilities.

<Card title="Ion Repository" icon="code" href="https://gitlab.redox-os.org/redox-os/ion">
  View the Ion shell source code on GitLab
</Card>

## Key Features

<CardGroup cols={2}>
  <Card title="Modern Syntax" icon="terminal">
    Clean, intuitive syntax inspired by modern shells
  </Card>

  <Card title="Rust Performance" icon="gauge-high">
    Fast execution with low memory overhead
  </Card>

  <Card title="Type Safety" icon="shield">
    Built-in type checking for variables and functions
  </Card>

  <Card title="Interactive Features" icon="keyboard">
    Advanced tab completion and history management
  </Card>
</CardGroup>

## Getting Started

Ion is the default shell for both root and regular users in Redox OS:

```toml theme={null}
[users.root]
password = "password"
uid = 0
gid = 0
shell = "/usr/bin/ion"

[users.user]
password = ""
shell = "/usr/bin/ion"
```

## Basic Usage

<Tabs>
  <Tab title="Commands">
    ```bash theme={null}
    # Run commands like any shell
    ls -la
    cd /home/user
    echo "Hello, Redox!"

    # Pipe commands
    cat file.txt | grep "pattern" | sort

    # Background processes
    long_running_command &
    ```
  </Tab>

  <Tab title="Variables">
    ```bash theme={null}
    # Define variables
    let name = "Redox"
    let count:int = 42

    # Use variables
    echo $name
    echo "Count: $count"

    # Arrays
    let files = ["file1.txt" "file2.txt" "file3.txt"]
    echo @files
    ```
  </Tab>

  <Tab title="Functions">
    ```bash theme={null}
    # Define a function
    fn greet name:str
        echo "Hello, $name!"
    end

    # Call the function
    greet "World"

    # Function with return value
    fn add x:int y:int -> int
        echo $((x + y))
    end

    let result = $(add 5 10)
    ```
  </Tab>

  <Tab title="Control Flow">
    ```bash theme={null}
    # If statements
    if test -f "file.txt"
        echo "File exists"
    else
        echo "File not found"
    end

    # For loops
    for file in *.txt
        echo "Processing $file"
    end

    # While loops
    let count = 0
    while test $count -lt 5
        echo $count
        let count += 1
    end
    ```
  </Tab>
</Tabs>

## Configuration

<Info>
  Ion can be configured through configuration files in the user's home directory.
</Info>

Ion is installed as part of the base system:

```toml theme={null}
[packages]
base = {}  # Includes Ion shell
```

## Built-in Commands

Ion provides several built-in commands:

| Command  | Description                      |
| -------- | -------------------------------- |
| `cd`     | Change directory                 |
| `echo`   | Print text to stdout             |
| `test`   | Evaluate conditional expressions |
| `let`    | Define variables                 |
| `fn`     | Define functions                 |
| `alias`  | Create command aliases           |
| `export` | Export environment variables     |
| `source` | Execute commands from a file     |

## Scripting

Ion supports advanced scripting with modern features:

```bash theme={null}
#!/usr/bin/ion

# Ion script example
let name = "Redox"
let version = "0.9.0"

fn show_info
    echo "Operating System: $name"
    echo "Version: $version"
end

fn check_system
    if test -d "/usr/bin"
        echo "System directories OK"
    else
        echo "Warning: System directories missing"
    end
end

show_info
check_system
```

## Environment Variables

Ion works with standard environment variables:

```bash theme={null}
# Set environment variables
export PATH="/usr/bin:/bin"
export HOME="/home/user"

# Access environment variables
echo $PATH
echo $HOME

# Use in commands
cd $HOME
ls $HOME/documents
```

## Integration with Redox

Ion integrates seamlessly with Redox OS features:

* **Scheme access**: Direct access to Redox schemes
* **Process management**: Native support for Redox processes
* **System integration**: Works with init system and services

```bash theme={null}
# Access schemes directly
cat scheme:debug
echo "test" > scheme:log

# Manage system services
notify ipcd
notify ptyd
```

## Performance

Ion is optimized for performance:

* **Fast startup**: Minimal initialization time
* **Low memory**: Efficient memory usage
* **Quick execution**: Optimized command parsing and execution

<Note>
  Ion is written in Rust, providing memory safety without garbage collection overhead.
</Note>

## Resources

<CardGroup cols={2}>
  <Card title="Ion Repository" icon="gitlab" href="https://gitlab.redox-os.org/redox-os/ion">
    Source code and development
  </Card>

  <Card title="Termion Library" icon="terminal" href="https://gitlab.redox-os.org/redox-os/termion">
    Terminal library used by Ion
  </Card>

  <Card title="Redox Book" icon="book" href="https://doc.redox-os.org/book/">
    System documentation
  </Card>

  <Card title="Trying Out Redox" icon="play" href="https://doc.redox-os.org/book/trying-out-redox.html">
    Get started with Redox and Ion
  </Card>
</CardGroup>

## Maintainer

<Card title="Jeremy Soller (@jackpot51)" icon="user">
  Primary maintainer of Ion shell
</Card>