How to send data from a file to a tcp connection via nc every x seconds

Source: https://stackoverflow.com/a/19271368

You can achieve it in two steps:

1) You need to start nc with a named pipe (fifo) as its input:

mkfifo /tmp/fifoIn; cat /tmp/fifoIn | nc localhost 2222 &

2) Send your data from file input.txt, line by line with 2 sec delay:

cat input.txt | while read line; do echo $line; sleep 2; done > /tmp/fifoIn

I've tested it with this "server" (I'm using openbsd netcat syntax):

nc -l localhost 2222

If you don't want the new-line char after every line use echo -n instead of echo.