How to write to file when using Marshal::dump in Ruby for object serialization

Question

Lets say I have the object line from class Line:

class Line
  def initialize point1, point2
    @p1 = point1
    @p2 = point2
  end
end

line = Line.new...

How can I binary serialize the line object? I tried with:

data = Marshal::dump(line, "path/to/still/unexisting/file")

but it created file and didn't add anything. I read the Class: IO documentation but I couldn't really get it.

Answer 1

Like this:

class Line
  attr_reader :p1, :p2
  def initialize point1, point2
    @p1 = point1
    @p2 = point2
  end
end

line = Line.new([1,2], [3,4])

Save line:

FNAME = 'my_file'

File.open(FNAME, 'wb') {|f| f.write(Marshal.dump(line))}

Retrieve into line1:

line1 = Marshal.load(File.binread(FNAME))

Confirm it works:

line1.p1 # => [1, 2]