Nc
nc is the command which runs netcat, a simple Unix utility that reads and writes data across network connections, using the TCP or UDP protocol. It is designed to be a reliable "back-end" tool that can be used directly or driven by other programs and scripts. At the same time, it is a feature-rich network debugging and exploration tool, since it can create almost any kind of connection you would need and has several interesting built-in capabilities. Common uses include:
Simple TCP proxies Shell-script based HTTP clients and servers Network daemon testing A Socks or HTTP ProxyCommand for ssh
Pemakaian
nc [-46bCDdhklnrStUuvZz] [-I length] [-i interval] [-O length] [-P proxy_username] [-p source_port] [-q seconds] [-s source] [-T toskeyword] [-V rtable] [-w timeout] [-X proxy_protocol] [-x proxy_address[:port]] [destination] [port]
Client / Server Model
It is quite simple to build a very basic client/server model using nc. On one console, start nc listening on a specific port for a connection. For example:
nc -l 1234
nc is now listening on port 1234 for a connection. On a second console (or a second machine), connect to the machine and port being listened on:
nc 127.0.0.1 1234
Mengirim Data
nc 127.0.0.1 1234 < filetest.txt