Archiving Zip. Compression. Stuff like that. Written by Dan Gookin Published by Quantum Particle Bottling Co., Coeur d’Alene, ID, 83814 USA Copyright ©2008 by Quantum Particle Bottling Co., Inc. All Rights Reserved. This work cannot be reproduced or distributed without written permission of the copyright holder. Various copyrights and trademarks may or may not appear in this text. It is assumed that the trademark or copyright is owned by whoever owns it, and the use of that material here is in no way considered an infringement or abuse of the copyright or trademark. Further, there is. Oh, wait. Never mind. I’m just making all this up anyway. I’m not a lawyer. I hate lawyers. For additional information on this or other publications from Quantum Particle Bottling Co., please visit http://www. wambooli.com/ Second Edition December, 2008 Table of Contents Archiving .........................................................................................................2 What the Heck is Archiving? ............................................................................4 Historical Nonsense About Compressed Folders and ZIP Files ..........................5 The Bad Old Modem Days .............................................................................6 Packing Multiple Files Into a Single Library ..................................................6 Better than Library Files, Compressed Archives ............................................7 Enter the ARC file format ..............................................................................8 From ARC to PAK to ZIP ...............................................................................9 Enter the Compressed Folder ........................................................................9 ZIP or Zip: What’s the difference?................................................................10 The ZIP Tutorials ...........................................................................................11 Creating a ZIP File Archive ..........................................................................11 Viewing the Archive ....................................................................................14 Adding Files to the ZIP Archive ...................................................................15 Managing Files in the Archive .....................................................................19 Extracting Files from the Archive ................................................................22 After you’re done with the archive, then what? ............................................26 Tutorial Cleanup.........................................................................................26 Drawbacks to ZIP Archives ............................................................................27 Advanced ZIP Archive Stuff ............................................................................28 Creating a ZIP Archive the Awkward Way ....................................................28 Installing a Program from a ZIP Archive ......................................................29 The Compressed Folder as EXE File Syndrome ...........................................30 Folders in ZIP Archives ...............................................................................30 Password Protection ...................................................................................30 E-mailing a ZIP Archive ..............................................................................33 A Few Words About WinZIP ............................................................................34 Blue Compression Archiving ..........................................................................34 Blue History ...............................................................................................34 Activating a file’s Blue Compression attribute .............................................37 It Didn’t Work! ............................................................................................38 Decompressing Blue Compression ..............................................................41 When you shouldn’t use Blue Compression ................................................41 It seems like ZIP archives are a bother with Blue Compression around .......41 ZIP Archives Versus Blue Compression:Pros and Cons ................................42 What the Heck is Archiving? Archiving is a fancy term for storing stuff in your computer. But it’s more than just using the FileSave As command to save a file, or even the Move and Copy commands to shuffle files around. No, archiving is about long term storage. It's about how to keep stuff you need, but may not need that often. Stuff that's too important to throw away — pictures, older documents, correspondence, and stuff like that. Archiving involves these things: Using the basic file commands to save and store your stuff, either on a secondary hard drive or a recordable CD. Storing things in a Compressed Folder or ZIP file. Using Blue Compression in Windows. I've written about the first method for years in my books. There's no point in repeating that information here. So this document is specifically about using Compressed Folders and Blue Compression. Historical Nonsense About Compressed Folders and ZIP Files Computer users have been archiving files for years, since the earliest days of primitive steam-powered computers, through the vacuum tube era, and into the transistor age. Cindy attempts to change archives without damaging her fingernails. Archiving is basically the art of keeping files around without deleting them. In the old days, that could be done by simply disconnecting a disk or tape and putting it into a vault. Today there are much more sophisticated ways of archiving, such as using the ZIP compressed file format. The following sections explain how the ZIP file format came about, why it was necessary, and stuff like that. If you’d rather just start with the tutorials, turn to page 5. The Bad Old Modem Days Another reason to archive is simply to keep files together, primarily for sending over a modem. Popular in movies, acoustic coupler modems such as this cheesy Tandy model from the early 1980s, were a royal pain in the butt to use. For example, go back to the bad old modem days, back before Windows. Back then, files were small say 16K in size on average. But yet the modems were slow. Sending a single file took a long time. That was still okay because most programs were simply one file. As things got more complex, programs would have more parts. Sometimes a single program would consist of five files. You would want to keep them all together when sending them from one computer to another. Rather than resort to unusual names or other weird techniques — stuff that few folks would understand let alone learn — the library file was developed. Packing Multiple Files Into a Single Library A Library File was simply a collection of multiple files. So if you wanted to send five files by modem: ALPHA BETA GAMMA DELTA EPSILON You could stuff them all into a single Library File named ALPHA.LIB. The Library program would create the file. You could then send the single file over the modem instead of the five files. If all went well, nothing was lost. The Library file illustration. On the other end, your pal receives the ALPHA.LIB file. He also has a copy of the Library utility, so he runs that program. In a few moments, the files stored in the ALPHA.LIB Library file are removed, orextracted , from the archive and you’re buddy has the five files he wanted: ALPHA BETA GAMMA DELTA EPSILON Library could be another word for “archive.” Indeed, this document could be called “Making Library files” instead of “Archiving.” But historically Library files were doomed. That’s because a better way to send files was developed: Thecompressed archive. Better than Library Files, Compressed Archives Library files solved one problem: they kept several disparate files together. The problem was that the Library File itself wasn’t compact. In fact, there was no time saving over sending a Library file versus sending all the separate files stored in the Library. The solution was compression. File compression is possible because computer files are composed of binary information, the ones and zeros of song and legend. 0111 0011 0110 1111 0110 1110 1001 0111 In a typical file, a lot of those ones and zeros are repeated over and over. It may seem wasteful, but such a thing is forgivable in a computer because storage isn’t considered a big deal. But when storage space or file size does become a big deal, it’s possible compress that binary information into a small size — just like you compress household garbage in a trash compactor. 0111 0011 0110 1111 0110 1110 1001 0111 Unlike a trash compactor, however, it’s fully possible to de-compress data in a file without losing any of the information. A file that has been compressed and de- compressed is the same as a file that hasn’t been ever compressed. Compression and decompression is made possible thanks to advanced mathematics and encryption stuff that I don’t understand and you don’t care about. The only drawback is that the computer cannot use a file in a compressed state: a text file cannot be read or a graphics file viewed when either is compressed. The file takes up less space, sure. But to use the file as intended, it must be decompressed. Enter the ARC file format Just as the Library files were becoming popular for sending programs and files over the modem, the ARC or Archive file format