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I have a 12 multi-part compressed archive of 5 files. Meaning originally there were 5 files, they were put into an archive of 12 parts. Of the 5 files, 3 are binary, 2 are text.
Is it possible to extract the raw data of any one part as-is?
- I don't mean to extract one of the 5 files. I want the raw data that is contained in any one of the 12 part files.
- To further complicate matters, I want to do this while only having parts from the middle, i.e. part 6, 7, 8, 9.
- And finally, this needs to be done for both ZIP and RAR formats separately.
Amer
Posted 2013-04-19T13:08:28.130
Reputation: 1 189
So you have parts 6-9 of 12, and want to extract the "raw data" of any one of those 4 parts instead of one of the 5 actual files inside? What does that even mean? If you just want the binary data of the archive as-is then just view any of the parts using a hex editor. – Karan – 2013-04-19T14:17:41.587
But if I were to view the parts using a hex editor I would not be seeing the original data, as the archiving process would have added some overhead and/or done some compression. I need to remove the archiving overhead and decompress the data. – Amer – 2013-04-19T16:37:03.833
So you do want to extract one of the 5 files. Why talk about raw data of the parts then? Also, are you using solid archiving for the RAR? – Karan – 2013-04-19T16:47:16.460
Well when I said I did not want to extract one of the 5 files, I meant I am not trying to get a file out in its entirety. Because say one of the files starts in part 5 and continues to part 8. So I can get the data of the file from part 6, 7 and 8, but I may not have the beginning of it. But if the file in its entirety exists in part 6, 7, 8, 9, then sure I am happy to get a complete file out. I am not sure about solid archiving, I just looked it up, but I don't know if it was used when compressing. – Amer – 2013-04-20T03:32:57.750
The way I see it, without access to the archive header (which might be stored in the first part or the last, you'll have to look up the ZIP and RAR specs to confirm) it'll be really difficult to determine where each file's data begins and ends. Solid archiving would make this even more difficult, and might even require (part of) the previous and next file's data to be available. You might have some luck with forensic tools that are purpose-built to handle such situations and recover as much data as possible, but it's not going to be easy IMO. Perhaps someone else might have better suggestions. – Karan – 2013-04-20T12:11:39.863