SFV files contain CRC32 checksums which can be used to determine wether or not the files listed were downloaded
correctly. So, after downloading a set of files, you can use a program like
SuperNZB
to calculate the CRC32 checksums and then compare them to the
checksums in the SFV file. If they match, then everything was downloaded perfectly.
If you open an SFV file with Microsoft Word, or any other word processor that can run scripts, it is possible
that a virus in the SFV could get you. When downloading text files, it always a good idea to open them with a
bare-bones text editor like NotePad on Windows and TextEdit on the Mac, both of which come free with your computer.
The files shown above are a typical RAR/PAR set. Any lines of the SFV file that begin with
a semicolon are comments and can be ignored. So, the first relevent line is: "Some.File.avi.part01.rar 5079A617."
"Some.File.avi.part01.rar" is the name of the file, and "5079A617" is the value calculated when the data from the
file is run through the CRC32 algorithm. "5079A617" is calculated on the computer of the person who posted the file.
If the copy of "Some.File.avi.part01.rar" that you now have yields a value of "5079A617" then you have an exact
copy.
Once you have SuperNZB installed, just click the "SFV" button on the main window:
The screenshot above was made on Windows, however the program looks identical on the Macintosh.
Here is a 5 minute demo video:
CRC32 can also be used to find duplicate files on your system. DupeNuker
keeps a database of CRC32 "fingerprints" so you can quickly tell if a new file is one you already have, or have already
seen before.