This simple program serves a single file over HTTP and prints the URL to the console both as text and as QR code, which makes it easy to transfer the file to smartphones.
qr-file-server <filename>
will serve the given file using an automatically selected (by the OS) port. Once the file is first served, the HTTP server shuts down and the program exits.
The program accepts a few optional flags which influence its behaviour. The usage is then
qr-file-server [-port <port>] [-keep] [-big] <filename>
-port <port> will make the program use the specified port instead of a random one
-keep will keep the program running after serving the file
-big will generate a bigger QR code
The program guesstimates the IP address to listen on by dialing an UDP connection to 8.8.8.8 and then reading the local IP address of this connection (regardless whether the connection was successful).