Archive for November, 2009

Trivial use of md5sum

I just made use of the [[md5sum]] command in a rather simple situation which could have been more troublesome to handle with other means. The following scenario highlights, IMHO, how [[command line]] greatly simplifies some tasks.

I have a file file.txt, and a collection of files file.txt.N, where N = 1, 2, 3… I know that the former is a copy of one of the latter, but I don’t know which. I could have run [[diff]] on all the possible matches, but I would have had to run it for every N until a match was found. However, md5sum comes to rescue. I can just run:

% md5sum file.txt*

And check which file.txt.N has a MD5 signature equal to file.txt, so that one would be the match. This solution is still a bit annoying, because I have to visually search matches for a long string. Not to worry! Unix is our friend once again. Recover the above command with a single press to the “up” arrow, then extend the command a tiny bit:

% md5sum file.txt* | sort

Now, since the MD5 signatures are sorted, the match for our file.txt (if there is any), will appear right after the line for file.txt.

I challenge the reader to accomplish the same task as readily, comfortably and successfully in Windows or Mac, or in Linux without the command line.

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