void curl_easy_cleanup(CURL *handle);
This will effectively close all connections this handle has used and possibly has kept open until now. Don't call this function if you intend to transfer more files.
Any uses of the handle after this function has been called are illegal. This kills the handle and all memory associated with it!
With libcurl versions prior to 7.17.: when you've called this, you can safely remove all the strings you've previously told libcurl to use, as it won't use them anymore now.