The example builds against an installed libvws together with the small examples-support library (libvwsx); the companion repository's build does this for you. It expects a WebSocket server on localhost port 8181, so start the server of Chapter 6, A WebSocket Server first, then run the client:

$ ./client-basic

It prints two lines: the echoed text reply (23 bytes — the hello over a text frame string) and the echoed binary reply (four bytes), each tagged with its byte count and opcode as the server returned them.