[MOVED & DON'T!] Offline Update using the command....

I have a limited connection therefore I use the following command for update

Code:

sudo apt-get upgrade --print-uris -y | grep -o "http:.*deb'"  | grep -o .*.deb > list

I download the files in the list from another computer and use pendrive to copy the files. and use the following command to update the packages.

Code:

sudo dpkg -i *.deb

it works well but even after updating the system the update manager shows list to update so i run the above commands again. but get list file shows nothing..

I have 2 doubts to be cleared

1. is there is any error in above commands or any other commands will do full offline update ??

2. I wish to know whether this command or any other command can be used for installing the software from the "Ubuntu software centre"??