Listen on a network port and save data to a text file [closed]

Answer 1

Netcat is your friend here.

nc -l localhost 10000 > log.txt

Netcat will listen for a connection on port 10000, redirect anything received to log.txt.

Answer 2

Other tools are Ethereal (man page) or Wireshark and it's console variant tshark.

In any case please be aware that you are following local and company rules.

Answer 3

Also available is TCPDump.

sudo tcpdump -i eth0 -vvvvtttAXns 1500 'port 10000'