RedFS is a mountable block system (not working yet)

redfs-fuse.rb

#!/usr/bin/env ruby
# RedFS (Fuse)
# RedFS is a mountable block system
# To make a RedFS virtual system, use the following shell command:
#     $ dd if=/dev/zero of=(yourfile) bs=4096 count=(number of blocks)
# To run:
#     # ./redfs-fuse.rb (yourfile) (mountpoint)
# or:
#     $ sudo ./redfs-fuse.rb (yourfile) (mountpoint)
# Also, please note that if when you write a block and it is larger than 4096 bytes, RedFS will cut off at that point.
require 'fusefs'
class RedFS < FuseFS::FuseDir
    BYTES_IN_BLOCK = 4096
    def close_base
        @file.close
    end
    def block_to_byte(n)
        b = n * BYTES_IN_BLOCK
       ((@file.size - 1) > b) ? b : nil
    end
    def total_blocks
        @file.size/BYTES_IN_BLOCK
    end
    def initialize
        @file = File.open(ARGV.first, 'r+')
    end
    def directory?(path); false; end
    def file?(path)
        false unless File.basename(path) =~ /^(\d+)$/
        block_to_byte(File.basename(path).to_i) ? true : false
    end
    def can_delete?; false; end
    def can_write?(path); file?(path); end
    def contents(path)
        (0..(total_blocks - 1)).to_a
    end
    def read_file(path)
        @file.pos = block_to_byte File.basename(path).to_i
        @file.readbytes BYTES_IN_BLOCK
    end
    def write_to(path, data)
        @file.pos = block_to_byte File.basename(path).to_i
        str = data[0..(BYTES_IN_BLOCK-1)]
        @file.write str
        @file.write "\0"*(BYTES_IN_BLOCK-str.size)
    end
end
if __FILE__ == $0
    root = RedFS.new
    FuseFS.set_root root
    FuseFS.mount_under ARGV[1]
    %w(INT TERM).each {|sig| trap(sig) do
        root.close_base
        FuseFS.unmount
    end }
    FuseFS.run
end