Net::FTP#retrbinary

# File tmp/rubies/ruby-3.0.5/lib/net/ftp.rb, line 647
def retrbinary(cmd, blocksize, rest_offset = nil) # :yield: data
  synchronize do
    with_binary(true) do
      begin
        conn = transfercmd(cmd, rest_offset)
        while data = conn.read(blocksize)
          yield(data)
        end
        conn.shutdown(Socket::SHUT_WR) rescue nil
        conn.read_timeout = 1
        conn.read rescue nil
      ensure
        conn.close if conn
      end
      voidresp
    end
  end
end