curl
80+ tested curl examples: GET/POST/PUT/DELETE, headers, auth, cookies, uploads, redirects, retries, and scripting.
networking
Networking, transfer, and connectivity
Copy files between two machines over SSH
Transfer a file or directory tree between two machines with scp or rsync, and resume an interrupted transfer without starting over.
Find and kill whatever is using a port
Identify the process bound to a TCP port that's refusing to let a service start, then stop it.