Catfood FTP (CFTP) is a rich command-line FTP tool that is well suited to updating web sites. CFTP supports transferring entire directory structures while automatically determining whether each file should be transferred in text or binary mode. Archive mode will only upload content that has been modified since the last transfer. It is also possible to transfer a single file, specify non-standard ports on the server and use an FTP proxy server. Advanced features include the ability to set permissions on UNIX servers (chmod) and selectively transfer files based on extension.