ncat

Listen on a port and save to file

$ ncat -l [port] > [path/to/file]

$ ncat -lk [port]

$ ncat < [path/to/file] [address] [port]

$ ncat --ssl -lk [port]

$ ncat --ssl [host] [port]

$ ncat -w [seconds] -vz [host] [port]

$ ncat -l [port] --chat

ncat [-l] [-k] [--ssl] [-w timeout] [-v] [-z] [host] [port]

ncat is a networking utility from the Nmap project for reading, writing, redirecting, and encrypting data across networks. It is a reimplementation of netcat with additional features including SSL support, proxy connections, and IPv6.
Ncat can operate as a simple TCP/UDP client or server, port scanner, or network relay. It supports connection brokering, access control, and can be used for file transfer, port forwarding, and network debugging.

-l, --listen

Listen for incoming connections

Accept multiple connections in listen mode

Use SSL/TLS encryption

Specify SSL certificate file

Specify SSL private key file

Connection timeout in seconds

Enable verbose output

Zero-I/O mode; report connection status only

Specify source port

Execute command after connection

Enable chat mode for multiple users

Connect through proxy

Proxy type: http, socks4, socks5

Use IPv4 only

Use IPv6 only

The --exec option can be dangerous and should be used carefully. SSL connections require proper certificate handling for security. Some features may require root privileges for privileged ports.

ncat was developed as part of the Nmap project by Fyodor and contributors. It was designed as a modern replacement for the traditional netcat utility with enhanced features and better security options.

nc(1), netcat(1), nmap(1), socat(1)