TermLib

Dart library for terminal applications. Part of termKit.

Features

• Text styling (colors, bold, italic, underlines, etc.)
• RGB/TrueColor with automatic down sampling
• Cursor control, screen clearing, alternate screen
• Keyboard input (including Kitty protocol)
• Mouse events, focus tracking
• Terminal hyperlinking, notifications
• Bracketed paste
• Synchronous updates

Installation

dependencies:
  termlib: ^0.1.0

Quick Start

Output and Styling

import 'package:termlib/termlib.dart';

Future<void> main() async {
  final term = TermLib();

  // Simple output
  term.writeln('Hello, terminal!');

  // Styled text
  term.writeln(term.style('Bold text')..bold());
  term.writeln(term.style('Red on blue')..fg(Color.red)..bg(Color.blue));

  // RGB colors (auto-downsamples if terminal doesn't support)
  term.writeln(term.style('Custom color')..fg(Color.fromString('#ff6600')));

  await term.dispose();
  await term.flushThenExit(0);
}

Terminal Control

import 'dart:io';
import 'package:termlib/termlib.dart';

Future<void> main() async {
  final term = TermLib();

  term
    ..enableAlternateScreen()
    ..eraseClear()
    ..cursorHide()
    ..setTerminalTitle('My App')
    ..writeAt(5, 5, term.style('Hello!')..fg(Color.cyan));

  sleep(const Duration(seconds: 2));

  term
    ..disableAlternateScreen()
    ..cursorShow();

  await term.dispose();
  await term.flushThenExit(0);
}

TermRunner

Recommended for apps needing raw mode, alternate screen, or signal handling. Handles setup, cleanup, and error recovery automatically:

import 'package:termlib/termlib.dart';

Future<void> main() async {
  await TermRunner(
    alternateScreen: true,
    rawMode: true,
    hideCursor: true,
    mouseEvents: true,
    title: 'My App',
  ).run((term) async {
    term.writeln('Press q to quit');

    while (true) {
      final event = await term.read<KeyEvent>();
      if (event is KeyEvent && event.char == 'q') break;
      term.writeln('Key: ${event}');
    }

    return 0; // exit code
  });
}

Features:

• Auto cleanup on normal exit, errors, and signals (SIGINT/SIGTERM)
• onCleanup callback for resource cleanup
• onError callback for custom error handling

Input Handling

TermLib detects interactive vs piped input automatically.

Interactive Mode (hasTerminal == true)

Events are queued in background. Use poll() (non-blocking) or read() (blocking):

...
// Non-blocking poll (for render loops)
final event = term.poll<KeyEvent>();
if (event is KeyEvent) {
  // handle key
}

// Blocking read (for CLI apps)
final event = await term.read<KeyEvent>();

Piped Mode (hasTerminal == false)

Use stdinStream with transformers:

import 'dart:convert';

...
if (!term.hasTerminal) {
  await for (final line in term.stdinStream
      .transform(utf8.decoder)
      .transform(LineSplitter())) {
    term.writeln('Line: $line');
  }
}

Raw Mode and Ctrl+C

When raw mode is enabled, Ctrl+C does NOT generate SIGINT - it arrives as a KeyEvent and must be handled manually.

Examples

See the example directory for more:

• colors.dart - Color palettes (ANSI, 256, TrueColor)
• color_table.dart - Downsampling demo from 256 to 16 colors
• key_viewer.dart - Interactive key event viewer
• matrix.dart - Matrix rain effect
• piped_input.dart - Processing piped input
• styles.dart - Text styling demo
• snake.dart - Simple game example
• term_info.dart - Terminal capabilities info

Acknowledgements

Inspired by dart_console, crossterm, termenv, termwiz, vaxis, mason.

License

MIT