Today I needed to verify that some files downloaded properly (without corruption due to it’s size of 2.4GB). I had the MD5 of the file handy but I’ve always wondered how I could get the hash of the file locally on my machine. I did a quick google search which gave me some options.
I picked the very first choice that I saw to see if it would work. It was called fsum. fsum is a command-prompt based application that you drop into a directory with your desired-to-be-verified-file and then you simply pass the file to the exe. In command prompt, after downloading and moving to it to my downloads folder, I did the following command,
I compared the returned MD5 (of course it does other things too) and it wasn’t corrupt! For a 2.4GB, it took about 20 seconds to read it all and then return the hash, but otherwise, it was very easy to use.
I also looked at a few other directly after getting my file verified. YAFIC seemed promising but I like that fsum can do more (and makes it clear that it can) than just sha-1. I saw AFIC (someone wasn’t very creative with the name) and it seemed a bit more difficult so I passed it by.
I’m very glad I didn’t have to program my own file integrity checker. It wouldn’t have been fun with Java and there isn’t a chance I would do it with C. Anyway, until I find something that’s even better (which I doubt), I recommend fsum by SlavaSoft!