Two layers of Zip files - is it safe?

FrankJH

FrankJH

FrankJH

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Ive worked in IT for a number of years but saw something for the first time today which got me thinking......

a pretty well known website (which I cant mention ) has pdf and financial data downloads, however this particular annual report had an initial compressed file with an excel file held in it along with a 2nd level of compressed file containing a pdf

What ever I did, I couldnt open the pdf (well I could see the file name of the pdf in the 2ndry level of zipped folder but I couldnt copy it anywhere outside the zip, I couldnt open it with adobe reader or anything else) - all this was tried on two seperate pc's to make sure.

I kept on getting generic windows errors regarding file structure etc

Has anyone come across this before - I cant think of any reason to do this apart from the original pdf coming from a different location originally and therefore potentially couldnt be compressed in the same folder as the xls

Is this method of distribution safe in regards to the file format structure / integrity during the 2nd process of compression?
 
Hmm, it's an interesting question but I don't see any obvious reason why multiple layers of compression would corrupt a file. For example, I have lots of zip files that are routinely backed up and compressed and I would expect them to work when decompressed.

When you tried on the second computer, did you redownload the file again or just transfer it across with a usb stick or something? I think it's more likely that the file was corrupted some other way.
 
I'm guessing your using the built in Windows archive support, 3rd party utilities such as WinRAR will open the archives in seperate windows and allow you to do what you want with them. I think the problem you encountered is actually a feature/limitation/bug related to the compressed folder implementation in Windows.
 
I have tried using the mentioned applications and no luck unfortunately.

Admittedly I downloaded it onto the same machine and then transferred it - but this was the 2nd attempt at downloading it to take any slight chance of d/l corruption out of the equation (hopefully)

I have to say I have never had any issue with the Windows compression utility - have a lot of you experienced failures using it?

Thanks again everyone :D
 
Nesting zip files like that works absolutely fine. Also, any decent antivirus software will scan a compressed file even if it's inside several zip files.
 
Mattus said:
Nesting zip files like that works absolutely fine. Also, any decent antivirus software will scan a compressed file even if it's inside several zip files.
Click to expand...

sorry - but no it obviously isnt fine as I was eventually able to get at the file after a lot of fiddling. If nesting did work "absolutely fine" then it shouldnt have been an issue in the first place :)

So the download was obviously ok, but the nesting is what caused the problem, imo anyway
 
Nesting does work fine, what he was telling you is that the Windows plugin or app you were using doesn't handle it properly.
 
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