Hi!
Most command line FTP clients support some degree of scriptability and/or output redirection, so you could use the FTP client's native functions, or the Posix operators such as ">" or ">>" to redirect the listing into a file. Unless it's Automic's own RA FTP Agent, with which this task will probably be more complicated.
If you desire any more than this somewhat generic answer, then please would you terribly mind sharing a few details with us, such as the platform, and most importantly, what FTP client you're using? Unless it is, in fact, the RA agent, that may turn out to be a question that doesn't really concern the Automic software much, but we'll try to give it a shot anyway.
Thanks!