Sometimes you're working on something and in a moment of inattention, you delete or overwrite some important file that you've been working on a long time and don't have a good backup or version-controlled copy of. All is not lost! Our fileserver keeps regular "snapshots" of all files in your home directory as a way to defend against this scenario.
Suppose you've been editing a few files in your directory. You've got two different cpp files, hello.cpp and other.cpp, as shown here:
After a bit of work, you decide you're done with other.cpp and ready to delete it. But in a moment of inattention, you delete the wrong one!
Oh no! But here is where you can check the snapshots. If you look in the directory /home/.snapshot you will find a number of directories labelled according to when the "snapshot" was taken:
In general, you'll be able to find hourly snapshots from the top of the hour for the last day or so; daily snapshots from just after midnight for the last week; and weekly snapshots from early Tuesday morning for the last month. The exact timestamp of each is noted in the filename (which gives the date in the format "2025-05-01" and the time after the underscore in 24-hour clock time, always four digits). For many cases you'll want the most recent hourly snapshot, but if you don't notice a mistake immediately you can select the date/time that works best.
Once you've chosen a snapshot to look at, inside that directory you'll look for your own username and, inside that, whatever sub-directory within your own home directory you'd like.
From that point it's just like any other file and you can edit and change it as necessary.