Netcat for File Transfer

File transfer is one of the most practical usages of netcat.

To transfer a file named filename from client to server, we first issue the following command on server:

nc -l -p 1234 > filename

where 1234 is the port number used by the server. On the client side, we issue:

nc -q 10 server 1234 < filename

where '-q 10' specifies to wait 10 seconds and then quit after EOF on stdin. This would cause the server to quit.

To transfer a director tree named /path from client to server, we issue the following command on server:

nc -l -p 1234 | tar xvzf -

On the client side, we issue:

tar cvzf - /path | nc -q 10 server 1234



If we want to reverse the direction of file transfer, i.e., client pulls file from server, we use:

nc -q 10 -l -p 1234 < filename

on server, and

nc server 1234 > filename

on client. Similarly, to reverse the direction of directory tree transfer, we use:

tar cvzf - /path | nc -q 10 -l -p 1234

on server, and

nc server 1234 | tar xvzf -

on client.