ENV['RAILS_ENV'] = ARGV.first || ENV['RAILS_ENV'] || 'production'
   require File.expand_path(File.dirname(__FILE__) + '/../config/environment')
   require 'rails'
   require 'rubygems'
   require 'json'
   
      # 仅处理一个article
   def fetch_image_and_rename_image_urls article
 
     puts "== processing: id: #{article.id}, title: #{article.title}"
   
     regexp = /https:\/\/img-blog\.csdnimg\.cn\/\w+.png/
     # 1. 获得某个article content中的所有图片
     article.content.scan(regexp).each do |url|
       puts url
       file_name = url.split('/').last
   
       # 2. 把这些图片都抓取到本地，并重新命名
       # https://img-blog.csdnimg.cn/13e29d1a43axxxxxxxxxxxxxxxxx.png
       #你想要把图片存放在哪个文件夹下面就把public/images/替换为它
       command = "wget #{url} -O public/images/#{file_name}"
       `#{command}`
 
       # 3. 把content中的老图片的URL， 替换成新图片的URL
       # https://img-blog.csdnimg.cn/13e29d1a43axxxxxxxxxxxxxxxxx.png
       # https://img-blog.csdnimg.cn/13e29d1a43axxxxxxxxxxxxxxxxx.png => /images/13e29d1a43axxxxxxxxxxxxxxxxx.png
       # 也就是说. https://img-blog.csdnimg.cn/ => /images
     end
     # 注意，记得把/images替换为你想要存放图片的文件
     article.content = article.content.gsub("https://img-blog.csdnimg.cn", "/images")
     article.save!
   end
   
   # 处理所有
   Article.all.each do |article|
     fetch_image_and_rename_image_urls article
   end