🐱 GoCat

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<div align="center"> <img src="https://raw.githubusercontent.com/ibrahmsql/gocat/main/assets/Gocat.png" alt="GoCat Logo" width="300" height="300"> </div>

A modern, feature-rich netcat alternative written in Go

🚀 Quick Start • 📖 Documentation • 💾 Installation • 🎯 Features • 🔧 Usage • 🤝 Contributing

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🌟 Overview

GoCat is a modern, cross-platform netcat alternative written in Go. It provides all the functionality of traditional netcat with additional features, better performance, and security. Whether you're a network administrator, security professional, or developer, GoCat offers the tools you need for network communication, debugging, and testing.

✨ Why Choose GoCat?

• 🚀 Fast & Lightweight: Built with Go for optimal performance
• 🌐 Cross-Platform: Works on Linux, macOS, Windows, and FreeBSD

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Key Features

Network Protocols

• TCP/UDP Support: Full support for both protocols with advanced options
• IPv4/IPv6: Native dual-stack support with proper formatting
• SSL/TLS: Secure connections with TLS 1.2+ and certificate validation
• Proxy Support: SOCKS5 and HTTP proxy support
• Keep-Alive: Configurable connection keep-alive
• HTTP Reverse Proxy: Load balancing with health checks
• Protocol Converter: TCPUDP, HTTPWebSocket conversion
• Port Forwarding: Advanced port redirection with statistics (NEW!)
• Packet Sniffer: Network packet capture and analysis (NEW!)
• Benchmark Tool: Network performance testing (NEW!)

Advanced Features

• Interactive Mode: Full PTY support with command history
• Connection Retry: Exponential backoff with configurable attempts
• Signal Handling: Graceful shutdown and signal blocking
• Timeout Control: Configurable connection and read timeouts
• Concurrent Connections: Handle multiple connections simultaneously
• Comprehensive Logging: Structured logging with multiple levels
• ✅ Timeout Control: Configurable connection and read timeouts
• ✅ Concurrent Connections: Handle multiple connections simultaneously
• ✅ Comprehensive Logging: Structured logging with multiple levels

🚀 New Features

• 🤖 MCP Server: Model Context Protocol integration - expose GoCat to AI assistants (Claude, etc.)
• WebSocket Support: Full WebSocket server/client with compression
• Unix Domain Sockets: Local IPC with stream and datagram support
• Prometheus Metrics: Built-in metrics exporter for monitoring
• SSH Tunneling: Local, remote, and dynamic SOCKS proxy tunnels
• DNS Tunneling: Covert channel for firewall bypass
• Multi-Port Listener: Listen on multiple ports simultaneously
• File Transfer: Efficient file sending and receiving
• Command Execution: Execute commands on remote systems
• Connection Persistence: Keep connections alive with heartbeat

🎨 User Experience

• Colorful Output: Syntax highlighting and colored logs
• Progress Bars: Visual progress indicators for transfers
• Verbose Logging: Detailed logging with multiple levels
• Shell Integration: Bash, Zsh, and Fish completion support
• Configuration Files: YAML/JSON configuration support
• Man Pages: Comprehensive manual pages
• Lua Scripting: Extensible with Lua scripts

🔒 Security

• ✅ Encryption: AES-256-GCM and ChaCha20-Poly1305 encryption
• ✅ Authentication: Token-based and password authentication
• ✅ Rate Limiting: Per-IP and global rate limiting
• ✅ Access Control: IP-based allow/deny lists with CIDR support
• ✅ Audit Logging: Comprehensive security event logging
• ✅ Input Validation: Extensive input sanitization and validation

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💾 Installation

📦 Package Managers

🍺 Homebrew (macOS/Linux)

brew tap ibrahmsql/gocat
brew install gocat

🐧 Arch Linux (AUR)

yay -S gocat
# or
paru -S gocat

📦 Debian/Ubuntu

wget https://github.com/ibrahmsql/gocat/releases/latest/download/gocat_amd64.deb
sudo dpkg -i gocat_amd64.deb

🎩 RPM (RHEL/CentOS/Fedora)

wget https://github.com/ibrahmsql/gocat/releases/latest/download/gocat_amd64.rpm
sudo rpm -i gocat_amd64.rpm

🚀 Quick Install Script

curl -sSL https://raw.githubusercontent.com/ibrahmsql/gocat/main/pkg/install.sh | bash

📥 Manual Download

Download the latest binary from GitHub Releases:

# Linux
wget https://github.com/ibrahmsql/gocat/releases/latest/download/gocat-linux-amd64
chmod +x gocat-linux-amd64
sudo mv gocat-linux-amd64 /usr/local/bin/gocat

# macOS
wget https://github.com/ibrahmsql/gocat/releases/latest/download/gocat-darwin-amd64
chmod +x gocat-darwin-amd64
sudo mv gocat-darwin-amd64 /usr/local/bin/gocat

# Windows (PowerShell)
Invoke-WebRequest -Uri "https://github.com/ibrahmsql/gocat/releases/latest/download/gocat-windows-amd64.exe" -OutFile "gocat.exe"

🐳 Docker

# Run directly
docker run --rm -it ghcr.io/ibrahmsql/gocat:latest

# Or use docker-compose
git clone https://github.com/ibrahmsql/gocat.git
cd gocat
docker-compose up

🛠️ Build from Source

# Prerequisites: Go 1.21+
git clone https://github.com/ibrahmsql/gocat.git
cd gocat
make build
# or
go build -o gocat .

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🚀 Quick Start

🎯 Basic Usage

🔗 Connect to a Server

# Connect to a TCP server
gocat connect example.com 80

# Connect with custom shell
gocat connect -s /bin/bash example.com 22

# Connect to IPv6 address
gocat connect "[2001:db8::1]" 80

👂 Listen for Connections

# Listen on port 8080
gocat listen 8080

# Listen with command execution
gocat listen -e /bin/bash 8080

# Interactive mode
gocat listen -i 8080

# Local interactive mode
gocat listen -l 8080

📁 File Transfer

# Send a file
gocat connect example.com 8080 < file.txt

# Receive a file
gocat listen 8080 > received_file.txt

# Send with progress bar
gocat connect --progress example.com 8080 < large_file.zip

🎨 Advanced Examples

🔍 Port Scanning

# Scan a single port
gocat scan example.com 80

# Scan multiple ports
gocat scan example.com 80,443,8080

# Scan port range
gocat scan example.com 1-1000

# Scan with timeout
gocat scan --timeout 5s example.com 1-65535

🌐 HTTP Reverse Proxy

# Simple reverse proxy
gocat proxy --listen :8080 --target http://backend:80

# Load balancing with multiple backends
gocat proxy --listen :8080 --backends http://backend1:80,http://backend2:80

# With health checks and SSL
gocat proxy --listen :443 --backends http://backend1:80,http://backend2:80 \
  --health-check /health --ssl --cert cert.pem --key key.pem

# Different load balancing algorithms
gocat proxy --listen :8080 --backends http://b1:80,http://b2:80 --lb-algorithm least-connections

🔄 Protocol Converter

# TCP to UDP conversion
gocat convert --from tcp:8080 --to udp:backend:9000

# UDP to TCP conversion
gocat convert --from udp:8080 --to tcp:backend:9000

# HTTP to WebSocket (NEW!)
gocat convert --from http:8080 --to ws://backend:9000/ws

# WebSocket to HTTP (NEW!)
gocat convert --from ws:8080 --to http://backend:9000

🔐 Encryption & Security

# Use encryption for connections
gocat connect --encrypt --key mykey example.com 8080

# Listen with authentication
gocat listen --auth --user admin --password secret 8080

# Rate limiting
gocat listen --rate-limit 100 --per-ip-limit 10 8080

# Access control
gocat listen --allow 192.168.1.0/24 --deny 192.168.1.100 8080

# Audit logging
gocat listen --audit-log /var/log/gocat-audit.log 8080

📜 Lua Scripting

# Execute Lua script
gocat script scripts/examples/http_client.lua

# Port scanner script
gocat script scripts/examples/port_scanner.lua

# Banner grabber
gocat script scripts/examples/banner_grabber.lua

# Custom SSL client
gocat script scripts/examples/ssl_client.lua

🔌 Multi-Port Listener

# Listen on multiple ports
gocat multi-listen --ports 8080,8081,8082

# Listen on port range
gocat multi-listen --range 8000-8100

# With command execution
gocat multi-listen --ports 8080,8081 --exec /bin/bash

# With statistics
gocat multi-listen --range 8000-8010 --stats

🌐 WebSocket Support (NEW!)

# Start WebSocket server
gocat ws server --port 8080

# WebSocket echo server
gocat ws echo --port 8080

# Connect to WebSocket server
gocat ws connect ws://localhost:8080

# WebSocket with compression
gocat ws server --port 8080 --compress

# Secure WebSocket (WSS)
echo "Hello WebSocket!" | gocat ws connect wss://secure.example.com/ws

🔌 Unix Domain Sockets (NEW!)

# Listen on Unix socket
gocat unix listen /tmp/gocat.sock

# Connect to Unix socket
gocat unix connect /tmp/gocat.sock

# Unix socket echo server
gocat unix echo /tmp/echo.sock

# Datagram socket
gocat unix listen --type datagram /tmp/dgram.sock

# With custom permissions
gocat unix listen --permissions 0600 /tmp/secure.sock

📊 Prometheus Metrics (NEW!)

# Start metrics exporter
gocat metrics --port 9090

# With custom namespace
gocat metrics --namespace myapp --subsystem network

# Access metrics
curl http://localhost:9090/metrics

# Health check endpoint
curl http://localhost:9090/health

🚇 SSH Tunneling

# Local port forw