"Encodes the file contents given by file-in, which can be of any form appropriate to with-open-file, and write the base-64 encoded version to sock, which is a socket.
Buffer-size, given in KB, controls how much of the file is processed and written to the socket at one time. A buffer-size of 0, processes the file all at once, regardless of its size. One will have to weigh the speed vs, memory consuption risks when chosing which way is best.
Wrap-at-column controls where the encode string is divided for line breaks."