Regularly back up the Ubuntu software installation list

In the past, when some software was installed on the machine, it would become very slow. At the same time, a script for regularly backing up the software installation list was written to monitor whether abnormal software was installed in the system. To resume installation if necessary:

#! /Bin/Bashdate='Date + % Y % m %D'Logfile= ~ /Ubuntuone/sharedwithme/Package. Selections. $ date>LogfileSudoDpkg -- Get-selections>$ Logfile #SudoDpkg -- Set-selections <~ /Package. Selections & apt-Get dselect-Upgrade

The red part should pay attention to the ''under ESC, rather than the single quotation mark''. I have not written it for a long time, and I have searched for the reason for a long time!