Local storage is extremely cheap these days when you consider the number of $200 CD burners, $100 40-GB hard drives, and 25-cent CDs out there. However, time is money. When trying to send files to someone, overnight shipping can be too slow, e-mail is not reliable for files over 3 MB, and even if you have the option of using FTP, a speedy modem connection will still take three minutes per megabyte. Which is where file compression comes into play.

PKZip is the original .zip compression tool. As a matter of fact, PKWare invented the .zip format in 1989. And the latest PKZip Suite offers some features that might come in handy for administrators.

I fondly remember using PKZip for DOS back in 1991 when I needed to share some files that didn’t fit on a single floppy. Since that time, PKZip has inspired a series of subsequent file compressions, such as ARJ, which have ultimately faded from the limelight. Ultimately, the .zip compression format withstood the test of time.

PKZip has traditionally been a GUI-based interface. Nevertheless, for relics like me, the new suite includes a DOS command-line variant. (See Figure A.)

Figure A
Just like the old days, PKZip Suite 4.5 allows DOS command-line functionality.

However, you should take advantage of the GUI (Figure B), unless you want to use Linux to change it (or Mac OS X, but that’s another article).

Figure B
The GUI should suffice for nearly all of your file compression needs.

Compression can be incredibly effective. Raw binary files, like BMP files, can be reduced to 40 percent of their original size, while plain text files can be compressed down to a mere 25 percent of their initial amount. However, already compressed data like JPG graphics will see only a small reduction, because only the header portion of the file is compressed.

PKZip Suite 4.5 features
The suite’s graphical mode will be familiar to everyone, even if it has more features than you might be accustomed to from a file browser. Just like earlier PKZip versions, you can use the included file browser to drag and drop files into the archives. By clicking on the Statistics tab, in addition to the normal file size, date, and attributes shown, you can get statistics on the archive and read any attached logs (Figure C).

Figure C
The Statistics tab on the file browser gives a lot of information about your system files.

File compression can be done using three different formats and 10 grades of compression. I recommend changing the default settings to maximum compression by clicking on the Options icon in the toolbar, selecting the Compress tab, and choosing the highest level in the Compression Options drop-down box (Figure D).

Figure D
While it may take more time to create or open the file, the time and bandwidth saved transferring the files will likely make up for it.

The security features will be of special interest for corporate use. Password encryption is quite common and not to be ignored. The PKZip software includes a very useful and rather unique tool called digital signatures, which is similar to the digital signatures used by many Web sites (Figure E).

Figure E
With PKZip, you can digitally sign your .zip file and its contents using a standard X.509-based certificate. One popular company, BT TrustWise, offers a trial digital signature certificate available from the PKWare Web site.

Any level-one, X.509-based certificate intended for e-mail files will work as your source, but you would be wise to use one that is widely recognized. PKWare recommends Verisign and BT TrustWise.

IT administrators should take advantage of the self-extracting archives PKZip can create to distribute software packages. Updates can then be distributed with archives consisting only of files that have changed since the last update. This saves additional space above and beyond the program’s standard compression capabilities.

This last upgrade feature to PKZip is one few people will use, but if you ever need it, you will really need it. Prior incarnations of the Zip format were limited to 4 GB and 65,532 files. Version 4.5 now supports up to 9 terabytes (9,000 gigabytes) and 4 billion files. PKZip Suite is available for $39.95 on physical media or $29.95 as an electronic download from PKWare.

Compression software like PKZip has proven to be reliable and widely accepted. Due to today’s increased bandwidth constraints, PKZip will still find a niche for itself, even though storage mediums have become cheaper to buy. This new version from PKWare, while not loaded with a bunch of new features, should prove worthwhile for the administrator looking to push a few more bytes through the system.