Reinstalling the uninstalled packages using a bash script to make things back to normal
I clearly don't see what going on. No output whatsoever. Here can't keep track of remaining packages to be reinstalled since I don't see anything. Help me see it.
This can be understood in many ways. As I understand your question, you want to debug your script, and your goal is to see what happens during script execution.
This can be achieved by invoking bash with the -x switch:
sudo /bin/bash -x ls.sh
From man bash:
-x Print commands and their arguments as they are executed.