ruby.rb

$upgrade_log="/tmp/su_upgrade.log"
$kept_back_packages_log="/tmp/su_kept_back.log" # Purely for debugging purposes.

# Generate a list of kept back packages.
packages=[]
IO.popen("apt-get upgrade -y --download-only 2>/dev/null >  #{$upgrade_log} ")
sleep(10)
puts "cat #{$upgrade_log}|awk 'BEGIN {flag=0} /kept back/ {flag=1;next} /upgraded/ {flag=0} flag==1 {print }' |tee  #{$kept_back_packages_log}"
IO.popen("cat #{$upgrade_log}").readlines.each{|l| puts l}
IO.popen("cat #{$upgrade_log}|awk 'BEGIN {flag=0} /kept back/ {flag=1;next} /upgraded/ {flag=0} flag==1 {print }' |tee #{$kept_back_packages_log}"){ |io|
  puts ">#{io} c| #{io.inspect}"
  while (io.gets)
    s=$_.strip
    puts s
    packages=packages+s.split(' ')
  end
}