Clone (at least ) an Ubuntu system installed software

To clone (at least ) an Ubuntu system (in terms of installed software, not settings or content ) to another system.Or make a backup. In terminal type

      dpkg --get-selections | grep -v deinstall > ubuntu-files

this command makes a file list of all installed packages in ur system(and stores it in present working directory).Backup this file in hdd,email, etc...(file is very small)

in the freshly installed ubuntu system

run

      sudo dpkg --set-selections <./ubuntu-files (will set it up and)

      apt-get -y update

      apt-get dselect-upgrade