kevin@kosman.UUCP (Kevin O'Gorman) (10/15/89)
I just lost a bunch of source-code files, it seems :-< Or, at least the latest version thereof. I have this THINK C project (the Crystal Cave game) which I stuffed and put on a shelf in August. It finally hit comp.binaries.mac this week, and some folks decided to take me up on my offer of source for the curious, so I took it off the shelf. Everything looks fine until I actually try to extract things. I have not tried them all, but the first five anyway give me an error message about checksums in the resource fork, and somewhere around the second attempt will bomb the Mac. This is very bad. There's enough good information for the trashed file to be on the desktop with the correct icon when I'm done, but as near as I can tell, the files are unusable. Does anyone have any information or experience about such stuff? Is there any hope of recovering the files? All stuffing and unstuffing is being done by StuffIt 1.5.1. under System 6.0.2 on a MacII. Lest you think I'm a total nitwit, let me assure you that there is another form of backup, but it's one update level old, and I don't have perfect memory of what got changed where to make the release version, so I would surely prefer to recover the files.
minow@mountn.dec.com (Martin Minow) (10/17/89)
In article <994@kosman.UUCP> kevin@kosman.UUCP (Kevin O'Gorman) says that he had archived some source files using Stuffit, but when he extracts the archive, Stuffit complains about "checksum errors" and bombs the Mac. Welcome to Lempel-Ziv-Welch compression. It compresses your file by an elegant (and hard to describe) method. The bad news is that a single bit error cascades -- and everything "downstream" of the error is total garbage. LZW works by -- essentially -- building a dictionary of subsequences and storing dictionary indexes in the compressed file. The decompressor rebuilds the dictionary as it expands the file. One consequence of this is that a single-bit error can result an illegal dictionary index and, ultimately, an illegal memory reference. I suspect you're out of luck. If you had source code for UnStuffit (or knew the archive format and had access to Unix compress to get the LZW algorithm), you *might* be able to extract parts of your files. >Lest you think I'm a total nitwit, let me assure you that there is another >form of backup, but it's one update level old, That was a smart move. Good luck. Martin Minow minow@thundr.enet.dec.com