require 'net/ftp'

Net::FTP

This class implements the File Transfer Protocol. If you have used a command-line FTP program, and are familiar with the commands, you will be able to use this class easily. Some extra features are included to take advantage of Ruby’s style and strengths.

ftp = Net::FTP.new('example.com')
ftp.login
files = ftp.chdir('pub/lang/ruby/contrib')
files = ftp.list('n*')
ftp.getbinaryfile('nif.rb-0.91.gz', 'nif.gz', 1024)
ftp.close

Block form:

Net::FTP.open('example.com') do |ftp|
  ftp.login
  files = ftp.chdir('pub/lang/ruby/contrib')
  files = ftp.list('n*')
  ftp.getbinaryfile('nif.rb-0.91.gz', 'nif.gz', 1024)
end

Net::FTP Reference