bash command to read from network socket?

Question

I am looking for a simple bash command to open a client socket, read everything from the socket, and then close the socket. Something like wget or curl for sockets.

Is there a command in Bash to do this? Of do I need to write a bash script?

Answer 1

Use nc. Its quick and easy. To connect to client 192.168.0.2 on port 999, send it a request for a resource, and save that resource to disk, do the following:

echo "GET /files/a_file.mp3 HTTP/1.0" | nc -w 5 192.168.0.2 999 > /tmp/the_file.mp3

Switch -w 5 states that nc will wait 5 seconds max for a response. When nc is done downloading, the socket is closed.

If you want to send a more complex request, you can use gedit or some other text editor to write it, save it to file "reqest", and then cat that file through the pipe to nc:

cat request.txt | nc -w 5 192.168.0.2 999 > /tmp/the_file.mp3

You don't need write a script for this, because it is a one line command... But if you will use it often, writing a script is a must!

Hope I helped. :)

Answer 2

Netcat is the tool usually used to do this, but it can also be done with the /dev/tcp and /dev/udp special pathnames.