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How to verify a file using md5sum

If you do not already have the md5sum.exe file, just obtain it when you download from anonymous ftp ftp://ftp.cownap.com/tools/md5sum.exe . (md5sum comes standard on most linux distributions - but for the most part that's not us).

You can copy it to one of two places. Either to the c:\windows\system32 directory, or to the same folder you downloaded your files to. The advantage of copying it to c:\windows\system32 is that you can then run it from anywhere on your computer - which is a real headache saver if you need to use it more than once.

md5sum must be run from a command prompt. The reason for this is that you must include the name of the file you want to check. Not a big deal, but just double clicking does not give you a chance to say which file you're checking. So the prompt window must be open.

So, open a command prompt and move to the folder where you downloaded the file. In my example, I began at c: but the file was in J:\usr so first I type J: in order to change to the J drive, then I type cd usr to move into the usr directory. You, of course, will adjust what you type in order to get to your file. Then just type mdsum (you don't need to include the exe part) and the name of the file you want to verify. For example md5sum Trucks.iso. The program will take a moment to check the file and when it's done it will display a long number. That number should match the one in the txt file you find in the anonymous ftp directory.

<center><img src="http://mtm2.com/~forum/images/md5sumcommandprompt.gif" width="463" height="331"></center>

<center><img src="http://mtm2.com/~forum/images/md5sumtextfile.gif" width="519" height="364"></center>

If it matches, you're good to go and may feel confident using it or burning it to cd/dvd.

If it does not match, then your file has not downloaded properly. Yes, it's true, a mistake could have happened when the md5sum.txt file was created (stranger things have been known to happen), but it's highly unlikely. If you try to download and consistently get a mismatch in the md5sum values, AND the file does behave as expected, then let me know and I will double check or regenerate the txt file on the server.

Note 1. One reason for a bad download might be if I update the file in the middle of your download.

Note 2. md5sum can work on any type of file. For example, the iso files available through anonymous ftp, as well as the large rar file on the fonts page.

If the command prompt is not your thing, then there is a gui version available at the link below. Note however, that I have never tried it. If you do, then by all means come back and let us know about what you find.

http://www.md5summer.org/

Thanks for explaining that

One more tip. Suppose you download the track files by year and you want to check each one but find comparing the results to the md5sum.txt file a bit straining. The solution would be to test the files all at one time and save the results to your own text file. To do that, save all the files to the same folder, then in the command window type

md5sum *.iso > mymd5sum.txt

The asterix means all files in the current directory will be tested, and the greater than sign means a file will be created in which the values will be stored, and of course the 'mymd5sum.txt' will be the name of the file (which you'll want to be different from the one you download because you'll (1) not want to overwrite the one you download, and (2) want to be able to tell them apart).

Depending on the speed of your computer this may take up to as much as five minutes, so start it running then go make yourself a sandwich or something. When you return, you can open both files for easy side by side comparison.

SLO Papa found a program for verifying isos called digestIT. He posted a note about it here.

http://n8s.net/yabbse/index.php?board=1 ... readid=614

I haven't tried it but it sounds handy.


DigestIt homepage - http://digestit.kennethballard.com/

> http://digestit.kennethballard.com/

Just a word to say the digestIT program does not work on the large tracks.iso file. I posted a note on the guy's forum but apparently it's a known issue and will be addressed in a future version. Also, the name of the program may be getting an update as well.

Meantime, I tested the second program that uses a gui. There's no installer, just click and go. The most recent update handles the large files correctly. This is really a nice little program.

http://www.md5summer.org/

For one hundred percent reliability, looks like the command line is still your best friend.

I just found out that nero has their own version of an md5sum checker. Seems to be a memory hog but it worked when I tested.

http://nero.com/enu/Nero_MD5_Verifier.html