nc

lets you create TCP (or UDP) connections from the command line

smiling stick figure, to box with smiley face: I hand wrote this HTTP request for you!

nc - l PORT

start a server! this listens on PORT and prints everything received

network connection -> nc -> stdout

nc IP PORT

be a client! opens a TCP connection to IP:PORT (to send UDP use -u)

make HTTP request by hand

printf 'GET / HTTP/ 1.1\r\nHost:example.com\r\n\r\n' | nc example.com 80

type in any weird HTTP request you want! (smiley face)

send files

want to send a 100GB file to someone on the same wifi network? easy!

receiver:
nc-1 8000 > file
sender: 
cat file | nc YOUR_IP 8080

happy stick figure with short curly hair: I love this trick It works even if you’re disconnected from the internet!