The default directory of sources.list is /etc/apt and when we call apt-get update system store package information in /var/lib/apt and synaptic or package manager read information from there. suppose i have some packages already downloaded in hard disk. so if read package info (sources.list) from desktop and add package information in another directory then i can use synaptic or apt to safely install packages and then restore again sources.list directory.

Procedure will be like this :

1. Have packages in desktop with sources.list information of packages directory (anywhere)


2. change default directory to desktop


3. synaptic or apt will read from desktop and save information in another place


4. install packages


5. restore back previous directory information