Backblaze restore and OS X unzip
I started using the Backblaze online backup (btw, check it out: unlimited backup of your internal and external disks for few bucks a month). Recently I downloaded a large restore zip and trying to list its content I got
Archive: restore.zip
warning [restore.zip]: 136677831514 extra bytes at beginning or within zipfile
(attempting to process anyway)
error [restore.zip]: start of central directory not found;
zipfile corrupt.
(please check that you have transferred or created the zipfile in the
appropriate BINARY mode and that you have compiled UnZip properly)
Quite scared I tried my best to understand why it was corrupted, along the lines of the message (binary mode, really, in 2011 there are still apps around that mess up with that?), but then a light turned on in my brain: was the 2GB file size barrier the culprit?
Googling around for "unzip 2gb" the first reference turned out to be the Python standard library, so I tried it and it worked! the file was indeed fine…
So, more anguish ahead, I discovered the the unzip command provided by OS X does not work with large files (despite what the man reports and the version number which should be new enough to cope with the Zip64 extensions).
Finally I settled on installing p7zip that is available via Homebrew and works with large files.
All's well that ends well…