How do I FTP multiple files from the command line?

Before issuing the mput command, issue a prompt command to disable Interactive Mode. Once that's off it shouldn't ask you to confirm each file for the mput (or an mget).

I've never tried using the pathname for local folders, but I have done it by changing the local directory (lcd):

username
password
ascii
cd "/destinationfolder"
lcd Backup
mput *.bak
close
quit

Try inserting the line prompt n just before the mput line