Question

How do I write (raw) a binary string array representation to a file?

#str is a String not an Array
str = "[80, 75, 3, 4, 10, 0, 0, 0, 0, 0, -74, 121, 57, 64, 0, 0, 0, 0]"

File.open('/Users/file.zip', "wb") do |file|
   file.write(str)
end

The code above does not work. How can I to fix it?

Answer 1

Most of the answers here assume you are using an Array, not a String as you stated (and as your example shows). This should work with the String you showed in the example:

File.open('/Users/file.zip', "wb") { |f| f.write(JSON.parse(str).pack('C*')) }

Just make sure to require 'json'.