$ bin/post -c tmp http://lucene.apache.org/solr/assets/images/book_sia.png -filetypes “*”
Entering auto mode. Indexing pages with content-types corresponding to file endings *
Entering crawl at level 0 (1 links total, 1 new)
SimplePostTool: WARNING: Skipping URL with unsupported type image/png
the mapping from image/png to a file type does not exist, and thus fails. This works in 'file' mode though.