tags	alias	created
port_scan bash networking tools	port_check bash scanner	2025-04-11

🛡️ Port Check Utility (port_check.sh)

A lightweight Bash-only TCP/UDP port scanner using /dev/tcp and /dev/udp.

✅ Features

• ✅ No external dependencies (no nmap, netcat, etc.)
• ✅ TCP and UDP support
• ✅ Color-coded output
• ✅ Logs to plaintext and CSV
• ✅ --quiet mode for background/cron usage
• ✅ Systemd and Docker ready
• ✅ Available as .deb, AppImage, Snap, and PyPI wrapper

🚀 Usage

./port_check.sh --hosts "example.com" [--ports "22,443"] [--udp] [--log logfile] [--quiet]

🧰 Options

Option	Description
--hosts	Required. Comma/space-separated hostnames or IPs
--ports	Optional. Default: 22, 80, 443, 8080, 8443
--udp	Use UDP instead of TCP
--log	Log to plaintext file, generates CSV beside it
--quiet	Suppress terminal output (requires --log)
--help	Show built-in help

🧪 Examples

• Basic TCP scan:

  ./port_check.sh --hosts "example.com"

• Custom ports:

  ./port_check.sh --hosts "example.com" --ports "21,22,80,443"

• UDP scan:

  ./port_check.sh --hosts "dns.server.com" --ports "53,161" --udp

• Logging + silent run:

  ./port_check.sh --hosts "host1" --log results.txt --quiet

📦 Install Methods

• Manual:

  cp port_check.sh /usr/local/bin/port_check
  chmod +x /usr/local/bin/port_check

• Debian:

  sudo dpkg -i port_check_1.0.deb

• Docker:

  docker run --rm -e HOSTS="host1" -e PORTS="22,443" yourdockerhub/port_check

📁 Output

• Plaintext log:

  [2025-04-11 10:25:30] TCP Port 22 is OPEN
  

• CSV log:

  "Timestamp","Host","Port","Protocol","Status"
  "2025-04-11 10:25:30","example.com","22","TCP","OPEN"
  

📄 License

MIT (c) 2025 Joel E. White