Check the header “Content-Disposition” to determine the filename to store

For example, the link http://audeering.com/download/1318/ (linked from http://audeering.com/technology/opensmile/#download) provides a Gzip-compressed tarball, but aria2 stored the tarball as the name index.html by the command aria2c -x4 http://audeering.com/download/1318/. This link returns the header Content-Disposition as attachment; filename="opensmile-2.3.0.tar.gz";, so aria2 must interpret it and store the tarball as the name opensmile-2.3.0.tar.gz.