I just learned a cool bash trick. Redirecting network traffic to a file.
Open two bash terminal windows.
t1$ nc -l 7777 >> TESTFILE
t2$ exec 3<>/dev/tcp/127.0.0.1/7777
t2$ echo 'Hello World!' >&3
t1$ cat TESTFILE
Your TESTFILE now has Hello World! in it.
There are quite a few ways to do this and similar operations, easy found on the Googles.
*Note: Other shells may work, I used bash. Your shell may or may not have redirection capabilities built into it.