Netcat is a versatile utility for working with TCP or UDP data. More information: <https://nmap.org/ncat>.

• Listen on a specified port and print any data received:
  nc -l port
• Connect to a certain port:
  nc ip_address port
• Set a timeout:
  nc -w timeout_in_seconds ipaddress port
• Keep the server up after the client detaches:
  nc -k -l port
• Keep the client up even after EOF:
  nc -q timeout ip_address
• Scan the open ports of a specified host:
  nc -v -z ip_address port
• Act as proxy and forward data from a local TCP port to the given remote host:
  nc -l local_port | nc hostname remote_port

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