May be if you want to turn off SFTP asking you YES/NO questions for each transfer of file when doing ftp using a ftp script file you can use -n -i command line arguments.
ftpscript.in
-----------------
user username pwd
get sourcefile targetfileonlocal
bye
Then you can run this script using ftp -n -i servername to avoid getting "Do you want to transfer the sourcefile?y/n" kind of questions. For logging into ftp server without user name, password then the server ftp needs to allow anonymous logins as mentioned by Wesley.
