⚡ BDH Terminal Engine (bdh-terminal-engine)

A 100% Pure Linux CLI Terminal Multiplexer & Standalone Text Editor, architected & built using an AI-Orchestrated Low-Level C Workflow.

Built for Backend Developers, Systems Engineers, and CLI Enthusiasts.

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📌 Overview

BDH Terminal Engine is a lightweight, high-performance terminal multiplexer inspired by tools like tmux and GNU screen, bundled with its own built-in and standalone modal text editor. Architected from the ground up to interact directly with Linux kernel pseudo-terminals (PTY), it manages virtual screen rendering, integrated text editing, and seamless text-based web browsing right inside your active terminal pane — with zero GUI dependencies.

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🔥 Key Features

• 🖥️ True Multi-Tab & Multi-Shell Multiplexing Spawn and manage multiple concurrent /bin/zsh or /bin/bash PTY sessions inside a single terminal window with instant keyboard and mouse switching.

• 📝 Built-in & Standalone Modal Text Editor (bdh-edit) Includes a fully functional, lightweight VT100 text editor. Launch it standalone via bdh-edit <filename> from any shell, or toggle it instantly inside the multiplexer engine using Ctrl + E — complete with a blinking block cursor (█) and clean alternate-screen isolation.

• 📱 Responsive Multi-Platform Capacity

  • Linux Desktop / Server Mode: Supports up to 18 concurrent sessions (MAX_SESSIONS 18).
  • Termux / Mobile Mode: Optimized lightweight layout supporting up to 8 concurrent sessions (MAX_SESSIONS 8) for clutter-free mobile screens.

• 🐭 XTerm SGR Mouse Protocol Support Click directly on any tab in the top badge or footer overlay to switch active sessions instantly without touching the keyboard.

• 🔍 Built-in Token Scanner (Ctrl + K) Scan the entire screen dynamically for URLs, IP addresses, UUIDs, and file paths, and copy them directly to your clipboard with a single keystroke.

• 🌐 100% Pure CLI Web Browser Integration Browse documentation, GitHub repositories, and websites directly inside your active tab using links, rendered in sharp, glitch-free ASCII/VT100 text mode (Ctrl + B).

• ⚡ Non-Blocking Asynchronous I/O & Zero-Gap Footer Powered by a responsive select() event loop with a 10ms timeout, ensuring zero input latency while maintaining a permanent, zero-gap Active Sessions Manager Footer Box at the bottom of your screen.

• 🛡️ 16KB Anti-Glitch & Anti-Tearing Buffer Engineered with a high-capacity 16,384-byte I/O buffer to eliminate screen tearing, flickering, and ghosting during heavy stdout bursts or full-screen browser layouts.

• 📦 Lightweight & Zero Bloat Compiles to tiny binaries (bdh-engine and bdh-edit). No X11, Wayland, GTK, or WebKit dependencies required — runs flawlessly on servers, SSH sessions, TTYs, Termux, and Linux desktops.

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🏗️ Modular Architecture

The engine is structured into clean, decoupled C modules for maintainability and extensibility:

Module	Source File	Core Responsibility
PTY Engine	src/engine/pty.c	Forking processes and creating pseudo-terminals (pty_spawn) via Linux system calls.
Session Manager	src/engine/session.c	Initializing, managing, and cleaning up multi-tab lifecycle arrays (8 to 18 sessions).
Virtual Screen	src/engine/screen.c, src/ui/panes.c	Detecting real terminal dimensions (ioctl) and maintaining off-screen window buffers.
ANSI / VT100 Parser	src/engine/parser.c	Parsing terminal escape sequences, CSI codes, cursor positioning, and line clearing.
Text Editor Engine	src/editor/edit.c, src/edit_main.c	Lightweight CLI text editing, row buffer rendering, file I/O, and standalone binary execution.
Mouse Parser	src/engine/mouse.c, include/engine/mouse.h	Decoding XTerm SGR mouse click/release events (\033[<btn;col;rowM) for instant UI interaction.
Input & Clipboard	src/engine/input.c, src/engine/clipboard.c	Handling raw keyboard shortcuts, mouse events, tab switching, copy/paste, and browser execution.
Token Scanner	src/engine/scanner.c	Extracting structured tokens (URLs, IPs, paths) from the screen buffer into clipboard storage.
Footer & Tabs UI	src/ui/tabs.c, src/ui/statusbar.c	Rendering the zero-gap BDH Active Sessions Manager footer box and status indicators.
Renderer	src/engine/renderer.c	Efficiently flushing the virtual screen state to the physical terminal without flickering.
Terminal Control	src/engine/terminal.c	Managing Linux terminal Raw Mode and restoring canonical settings cleanly on exit.

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🛠️ Prerequisites & Installation

1. Install System Dependencies

Arch Linux / Manjaro:

sudo pacman -S --needed gcc make links

Ubuntu / Debian:

sudo apt update && sudo apt install -y build-essential links

Termux (Android):

pkg update && pkg install -y clang make links

2. Build & Install the Project

Clone the repository and compile using the included Makefile:

# Clone repository
git clone https://github.com/BackendDeveloperHub/bdh-terminal-engine.git
cd bdh-terminal-engine

# Build clean executables and install globally
make clean && make && sudo make install

Note for Termux users: Run make clean && make && make install (without sudo).

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🚀 Usage

1. Start the Multiplexer Engine

Start the terminal engine directly from any shell (optionally pass a filename to open in the built-in editor):

bdh-engine [optional_filename.txt]

2. Launch the Standalone Text Editor

Open or create a file using the standalone CLI text editor:

bdh-edit filename.tz

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⌨️ Keyboard & Mouse Controls / Action Triggers

Shortcut	Action
Ctrl + A	Switch to the next active Tab / Session sequentially
Ctrl + E	Toggle the built-in full-screen modal text editor on/off
Ctrl + B	Launch the CLI Web Browser (links) inside the currently active tab
Ctrl + K	Trigger the Token Scanner to scan and copy URLs/IPs from the screen
Ctrl + S	Save the active file (while in Editor Mode)
Ctrl + X	Exit Editor Mode and return to the multiplexer shell
Mouse Left Click	Click on any session tab to switch directly to that session
Ctrl + Q	Safely terminate the engine and restore canonical terminal settings

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🏗️ Engineering Notes

Early iterations of bdh-terminal-engine experimented with embedded graphical WebKitGTK windows. However, GUI loops (gtk_main_quit) clashed with the low-level PTY select() loop, adding megabytes of bloat and restricting usage to desktop environments.

By refactoring to a 100% Pure Linux CLI Multiplexer & Modal Editor:

• Zero Crash Rate — Removed all display server (DISPLAY=:0) and GTK signal errors.
• Server & Mobile Ready — Perfectly functional over headless SSH connections, minimal Arch Linux installations, and Termux mobile environments.
• High Performance — Reduced binary size and memory footprint by over 99%.

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👨‍💻 Author & Engineering Workflow

Prabakaran202 (Backend Developer Hub - BDH Linux) Systems Architecture & Engineering Design | AI-Assisted Low-Level C Implementation | Python / FastAPI | Arch Linux

A note on modern engineering: This engine was conceptualized, architected, and debugged using an AI-assisted systems engineering workflow — combining human architectural vision with AI-driven code generation for rapid, low-level C development.