OS X and the “cat” command for appending sequential .zip files

For whatever reason there is certain a level of incompatibility between various .zip (archive) file formats among various operating systems today.  It’s certainly not that you won’t be able to access any file type on any given system, as there are many tools to do so, mostly it’s a question of how many hoops you have to jump through.

Specifically, I had a sequential .zip file that was in multiple chunks where the first file ends in something like:

zzzzzz.zip.001.zip

And the next files in sequence look like this:

zzzzzz.002
zzzzzz.003

OS X comes with a couple of utilities for archives but neither seem to be able to handle this particular sequence (especially if it is AES256 encoded with a password).  There is a $20 piece of software called BetterZip that has no problem with any type I gave it, however, I found a free utility called The Unarchiver which seems to be an excellent replacement for the OS X native ‘BOMArchiveHelper.app‘ and if you use the *nix ‘cat‘ command (see: Concatenation) you can append the sequential files all into one and The Unarchiver will work fine.

Open the Terminal in OS X, red is what you type, assuming all the files you want to append are in your home directory:

computer:~user$ cat zzzzzz.zip.001.zip zzzzzz.002 zzzzzz.003 > onebigfile.zip

Where onebigfile.zip is your new appended file, ready to be unarchived.  I’m sure they teach this to preschoolers in *nix 101, in fact I think there is a book out now called Linux For Lilliputian Lads, but I found it useful.

I’ll be doing a writeup soon of the re-foaming process of my Advent Heritage speakers, they sound better now.