/readline

A Pure C# GNU-Readline like library for .NET/.NET Core

Primary LanguageC#MIT LicenseMIT

Windows build status License: MIT NuGet version

ReadLine

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.

It is cross platform and runs anywhere .NET is supported, targeting netstandard1.3 means that it can be used with .NET Core as well as the full .NET Framework.

Shortcut Guide

Shortcut Comment
Ctrl+A / HOME Beginning of line
Ctrl+B / Backward one character
Ctrl+C Send EOF
Ctrl+E / END End of line
Ctrl+F / Forward one character
Ctrl+H / Backspace Delete previous character
Tab Command line completion
Shift+Tab Backwards command line completion
Ctrl+J / Enter Line feed
Ctrl+K Cut text to the end of line
Ctrl+L / Esc Clear line
Ctrl+M Same as Enter key
Ctrl+N / Forward in history
Ctrl+P / Backward in history
Ctrl+U Cut text to the start of line
Ctrl+W Cut previous word
Backspace Delete previous character
Ctrl + D / Delete Delete succeeding character

Installation

Available on NuGet

Visual Studio:

PM> Install-Package ReadLine

.NET Core CLI:

dotnet add package ReadLine

Usage

Read input from the console

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

Read password from the console

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

Note: The (prompt>) is optional

History management

// Get command history
ReadLine.GetHistory();

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

// Clear history
ReadLine.ClearHistory();

// Disable history
ReadLine.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.