zero1ne / libvt100

A purely .net/C# library for parsing a VT100/ANSI stream

libvt100

A purely .net/C# library for parsing a VT100/ANSI stream

When writing anything that needs to communicate with a terminal in some way it is almost always speaking some dialect of VT100 or ANSI.

This library aims solely at parsing a stream of VT100/ANSI data and then letting the host application do the rendering. Many other project also parse VT100/ANSI data but their parser is always tangled up with the actual rendering of the data, making reuse in other projects problematic.

Projects Using libvt100:

• winprint - Uses libvt100 to parse and print source code files that have been 'syntax highlighted' by Pygments and output using Pygment's terminal256 Formatter. The terminal256 formatter generates ANSI escapes for formatting. This code takes an input document:

_screen = new DynamicScreen(_minLineLen);
    IAnsiDecoder vt100 = new AnsiDecoder();
    vt100.Encoding = Encoding;
    vt100.Subscribe(_screen);
    var bytes = vt100.Encoding.GetBytes(Document);
    if (bytes != null && bytes.Length > 0) {
        vt100.Input(bytes);
    }

Then the winprint rendering engine simply enumerates over this (psuedocode):

    foreach (var line in _screen){
        SmartlyDrawLine(line);
    }

Real code is here:

https://github.com/tig/winprint/blob/eee9768506f08e2f5af75f90d9571dc94d8d42fa/src/WinPrint.Core/ContentTypeEngines/AnsiCte.cs#L196

A cool thing about this is features like line-wrap and /t expansion are handled by libvt100.

Hopefully other projects will start using libvt100 and we can stop reinventing the wheel in each project.