Question

If there is an image at a public url, how would I write and save it to my local filesystem using Ruby?

Answer 1

require "open-uri"

open("http://www.whatever.com/x.png") do |hnd|
  File.open("x.png","wb") {|file| file.puts hnd.read }
end

EDIT:

This allows you to use open to load a website, and treat it as normal file handle:

require "open-uri"

This loads your image, and passes a handle to the page body, as the parameter hnd:

open("http://www.whatever.com/x.png") do |hnd|

This opens a file in binary mode ( needed on Windows systems ), and writes the page’s content into it:

File.open("x.png","wb") {|file| file.puts hnd.read }

The content is obtained via the read method, which tries to read it completely before writing it.