I've tried to use this to receive the contents (and echo it), but I get the error of file not found, could anyone help me? Thanks in advance
netcat -l 127.0.0.1 1234 < file.txt
EDIT:
I've got it in a wrong way, problem solved now!
To output to stdout and to file.txt:
netcat -l 127.0.0.1 1234 | tee file.txt