Linux NC command detailed "scan ports, chat tools, transfer files" __linux

Introduction to NC commands

NC process is netcat is a common network tool (the Swiss knife of the network); NC communication reads and writes data through TCP/IP protocol,

Can be TCP, UDP after network link communication.
The most reusable function of the NC scan Port NC is to scan the port for opening, a bit like telnet:

Nc-v-W 2 ' hostname-i ' 3901-3905
nc:connect to 10.246.46.15 Port 3901 (TCP) Failed:connection refused Nc:conn
ECT to 10.246.46.15 Port 3902 (TCP) Failed:connection refused
Connection to 10.246.46.15 3903 Port [Tcp/charsetmgr] s ucceeded!  #端口开通
nc:connect to 10.246.46.15 Port 3904 (TCP) Failed:connection refused Connection to
10.246.46.15 3905 Port [Tcp/mupdate] succeeded!     #端口开通

You can use the NC return value to determine whether the port is open

Nc-v-W 2 ' hostname-i ' 3901
nc:connect to 10.246.46.15 Port 3901 (TCP) Failed:connection refused
echo $?
  
   1

nc-v-W 2 ' hostname-i ' 3903
Connection to 10.246.46.15 3903 Port [tcp/charsetmgr] succeeded!
echo $?
0

  

NC Chat Tools

NC is a TCP/IP network protocol tool that is sure to be followed by TCP connections, and can simulate one of the simplest chat tools with NC: Server-side "any side"

Nc-l 55555
shi ni 
shiwo^h^h
ni hao shuming
ni shmming

Client side "either side"

NC 10.246.46.15 55555
shi ni 
shiwo
ni hao shuming
ni shmming

NC Transfer Files

Since NC is a network connection to the TCP/IP protocol, you can use NC to establish a connection to transfer file transfer files to write the contents of the file to the NC-enabled port listen

Cat rpyc.py |nc-l 33333

Receives the file side, the NC connects transmits the file machine the listen port, and receives the file to write in the specified file

NC 10.246.46.15  33333 > rpyc.py

NC Usage: http://www.huanxiangwu.com/477/linux-nc-netcat