ReadLine.Ext

This library is an enhanced clone of tonerdo/readline that adds the following extras ;

• Allows ReadLine to be used not only with the default System.Console but also any user-supplied virtual console that extends ReadLine.IConsole.
• The library adds a supporting class ReadLine.KeyParser that can parse Ansi/VT-100 escapecodes into System.ConsoleKeyInfo to make it easy to implement custom IConsole classes. The KeyParser uses an embedded copy from the implementation used in System.Console (net7.0 version).
• The library is cross platform but requires net7.0 or greater.

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ReadLine is a GNU Readline like library built in pure C#. It can serve as a drop in replacement for the inbuilt Console.ReadLine() and brings along with it some of the terminal goodness you get from unix shells, like command history navigation and tab auto completion.

Shortcut Guide

Shortcut	Alias	Comment
Ctrl+A	Home	Go to beginning of line
Ctrl+E	End	Go to end of line
Ctrl+B	←	Go backward one character
Ctrl+F	→	Go forward one character
Alt+B	Ctrl+←	Go backward one word
Alt+F	Ctrl+→	Go forward one word
Ctrl+C	Ctrl+Z	Send EOF
Ctrl+H	Backspace	Delete previous character
Ctrl+D	Delete	Delete succeeding character
Ctrl+J	Enter	Line feed
Ctrl+L	Esc	Clear line
Ctrl+P	↑	Backward in history
Ctrl+N	↓	Forward in history
	F3	Last in history
	Insert	Toggle insert mode
Ctrl+I	Tab	Command line completion
	Shift+Tab	Backwards command line completion
Ctrl+U	Ctrl+Home	Cut text to the start of line
Ctrl+K	Ctrl+End	Cut text to the end of line
Ctrl+W	Ctrl+Backspace	Cut previous word
Alt+D		Cut succeeding word
Ctrl+T		Swap last two chars before the cursor (typo)

Usage

Read input from the console

string input = ReadLine.Read("(prompt)> ");

Note: The (prompt>) is optional

Read password from the console

string password = ReadLine.ReadPassword("(prompt)> ");

Read input from custom context/console

class MyConsole : IConsole { ... };
var context = new ReadContext { Console = new MyConsole() };
var input = context.Read("(prompt)> ");

ReadContext defines the Console, Command-History and Auto-Completion to use.

Convert char[] to ConsoleKeyInfo[]

char [] input = ... ;
ConsoleKeyInfo[] keys = ReadLine.KeyParser.Parse(input);

History management

// Get command history
var history = ReadLine.Context.History;

// Add command to history
ReadLine.Context.History.Add("dotnet run");

// Clear history
ReadLine.Context.History.Clear();

// Disable history
ReadLine.Context.HistoryEnabled = false;

Note: History information is persisted for an entire application session. Also, calls to ReadLine.Read() automatically adds the console input to history

Auto-Completion

class AutoCompletionHandler : IAutoCompleteHandler
{
    // characters to start completion from
    public char[] Separators { get; set; } = new char[] { ' ', '.', '/' };

    // text - The current text entered in the console
    // index - The index of the terminal cursor within {text}
    public string[] GetSuggestions(string text, int index)
    {
        if (text.StartsWith("git "))
            return new string[] { "init", "clone", "pull", "push" };
        else
            return null;
    }
}

ReadLine.AutoCompletionHandler = new AutoCompletionHandler();

Note: If no "AutoCompletionHandler" is set, tab autocompletion will be disabled

Contributing

Contributions are highly welcome. If you have found a bug or if you have a feature request, please report them at this repository issues section.

Things you can help with:

• Achieve better command parity with GNU Readline.
• Add more test cases.

License

This project is licensed under the MIT license. See the LICENSE file for more info.