Rails/Ruby:上传二进制文件并使用File-Object编写它

<%= form_with(url: "/upload", method: "post", multipart: true) do |form| %>
  <%= form.label :file %>
  <%= form.file_field :file %>
  <%= form.submit "Upload" %>
<% end %>

class UploadController< ApplicationController
  def create
    file = params[:file]
    File.open(Rails.root.join("uploads/#{file.original_filename}"), "wb") do |f|
      f.write(file.read)
    end
    redirect_to "/"
  end
end

Rails.application.routes.draw do
  post "/upload", to: "upload#create"
end

file_path = Rails.root.join("uploads/example.txt")
File.open(file_path, "w") do |file|
  file.write("Hello, world!")
end