Send String over netcat connection

Question

I have two virtual machines open, one is listening on the connection, the other connects with nc <ip> <port> from a python subprocess call. I want to send just 1 line of text over the connection then close it. I know how to send a file cat cat <file> | nc <ip> <port> but how can I just send a line of text in the nc command (without using files)?

Sorry I was unclear, I don't want to use files at all in any way, just strings — Crizly, May 23 '16 at 11:08
Is there any way to capture this data (text) reached to another VM which is listening on the connection. — Manjunath Raddi, May 09 '18 at 12:16

score 24 · Accepted Answer · answered May 23 '16 at 11:14

24

Try this:

echo -n 'Line of text' | nc <ip> <port>

You can also use temp file syntax:

cat <(echo "Line of test") | nc <ip> <port>

answered May 23 '16 at 11:14

cb0

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With `cat | nc -vl localhost` you can make netcat send data to the client from standard in, your keyboard for example. This works after the connection was established with the client. – Matthias Braun Jun 15 '22 at 15:07

score 3 · Answer 2 · answered Dec 19 '20 at 15:07

3

The temp file syntax shown by @cb0 could also be used as:

nc <ip> <port> <( echo "Line of text" )

without having to use cat command. This would create a temporary file with the content "Line of text" and then redirect it to the netcat command.

answered Dec 19 '20 at 15:07

geekypandey

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score 1 · Answer 3 · answered May 09 '18 at 12:19

1

Create file test.txt, content of file is 1

netcat [ip-address] [port] <test.txt

At destination you must have something to listen to this.

answered May 09 '18 at 12:19

Manjunath Raddi

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score 0 · Answer 4 · answered Mar 12 '23 at 15:36

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-N flag is required to exit nc after a message is sent for some servers:

echo "text" | nc -N <ip> <port>

-N shutdown(2) the network socket after EOF on the input. Some servers require this to finish their work.

-- man nc

answered Mar 12 '23 at 15:36

angordeyev

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Send String over netcat connection

4 Answers4