set wallpaper from reddit EarthPorn, in ruby

earthporn-to-wallpaper.rb

#
#  SCHTASKS /Create /F /TN wallpaper-from-reddit  /TR "C:\usr\bin\ep.bat" /SC HOURLY
#  ep.bat :
#    rubyw C:\usr\bin\earthporn-to-wallpaper.rb

path="c:/usr/www/images/ep"
fr=path+"/fpersist.rb"
if ARGV.first == "delete"
  puts "Delete all jpeg file in '#{path}' directories ..."
  Dir.glob(path+"/*.jpg").each {|fn| File.delete(fn) } 
  File.delete(fr) if File.exist?(fr)
  ARGV.shift
end

require 'open-uri'
require 'ruby_reddit_api' # gem install ruby_reddit_api


####################### Windows stuff

require 'Win32API' # for beep and set wallpaper on desktop

Beep = Win32API.new("kernel32", "Beep", ["I", "I"], 'I')

$systemParametersInfo = Win32API.new('user32', 'SystemParametersInfo', ['I','I','P','I'], 'I')
SPI_SETDESKWALLPAPER = 20
SPIF_UPDATEINIFILE = 0x1
SPIF_SENDWININICHANGE = 0x2

def  winWall(filename)
    $systemParametersInfo.call(SPI_SETDESKWALLPAPER, 0, filename, SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE)
end

# get WEB binary data, write file in binary format ('rb/wb' read-binary/write-binary ==> specific windows)
def binary_get_write(url,filename,min_size=0,max_size=0) 
  open(url,"rb") { |con| 
	data=con.read
	if data.size>=min_size && data.size<= max_size
		open(filename,"wb") { |f| f.write(data) } 
	end
  }
  true
rescue Exception => e
  puts "\nError getting #{url} to file #{filename} => #{e}"
  false
end

##################### M a i n ####################### 
th=nil
n=0

lknown={}
#===== Load list of file already scanned
( lknown=eval(File.read(fr)) if File.exist?(fr) ) rescue puts "error reading memory #{$!}"

Beep.call(4000, 30)
Reddit::Api.new.browse('earthPorn').each do |r|
  print "."
  url= r.url 
  next unless url =~ /\.jpg$/ 
  filename=path + "/" +File.basename(URI(url).path.downcase)
  next if lknown[filename]
  lknown[filename]=1
  next if  File.exist?(filename)
  ok=binary_get_write(url,filename,130_000,3000_000)
  if ok && File.exist?(filename)
	  n+=1
	  puts "\n#{n} #{filename} ==> #{File.size(filename)/1024} KB" 
	  th=Thread.new(filename)  {|fn| sleep 0.1 ; winWall(fn) }
  end
end
th.join if th 
File.write(fr,lknown.to_a[-200..-1].to_h.inspect) # update memory of file scanned, LRU
Beep.call(3000, 30)