DeLorean is a clone of Apple’s Time Machine product, for Linux/Un*x systems, written in Perl.
It allows you to save daily backups of one or more files or directories on your system. To save space, it takes advantage of the filesystem’s hard link feature. A hard link allows two or more files to share the same data. So, if you’ve got a 1 megabyte file, and you don’t make any changes to it for a month, you only need a total of 1 megabyte to store the 30 daily copies of that file. If you delete one of the daily copies, the others will survive (until you remove the last one).
By creating daily snapshots, Time Machine allows you to “go back in time” and view all of your files and directories as they existed at some point in the past. In addition to the daily backups, DeLorean will automatically save a weekly snapshot every Monday, and a monthly snapshot on the first day of each month.
It’s easy to use — just edit the sample_usage.sh script to fit your needs, and put it in your daily crontab. The only things you’ll need to change are the data directory(ies) that you want it to protect, and the backup directory where you want to store the snapshots. (Obviously, the latter should not be a subdirectory of the former.) It would be a good idea to store your backup directory on a separate drive, such as an external hard drive or a network share.
You should not make any changes to the files in your backup directory, though, or you will change every backed-up copy of that file! To restore an old copy of a file that you need, you must first copy it back to your data directory (or somewhere else on your system) and edit it there.
You can download the Perl code from my GitHub here.