 The magazine of the Melbourne PC User Group What to do with BBS files Dave Mitchell |
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You may not be aware the BBS carries approximately 4 gigabytes of files available for downloading. The great majority of these files are full and complete suites of programs that have been archived. Now, what is archiving?
In some respects archiving is similar to the traditional DOS backup procedure where many files are combined into one. However, archiving utilities compress all the empty space in the files they process; they also employ a few other tricks to save space. The resulting archive is much smaller than you would expect by simply combining the original files at their normal, full size. This procedure makes both storage and downloading much more efficient.
Archive types
There are two main archive types on our BBS plus a smattering of self-extracting archives. All files ending with the extension.ZIP have been archived using the PKZIP archiving utility by PKWare. Files ending with the extension .LZH have been archived using LHARC by Yoshi.
Self-extracting archives end with the extension .EXE and when run just like you would any other executable file, simply by typing the name and pressing Enter, they will self-extract.
The tools you need
To make use of the files inside an archive, first you must extract them from the archive. To do this you must have the appropriate archiving utility on your computer. Before we go any further, lets discuss how to obtain the required tools.
In the files section on the BBS, Area 1 is titled Sysop's Favourites. There you will find two files you should make the target of your first download. These files are named LHA213.EXE and PKZ204G.EXE. As the .EXE extensions will suggest, both files are self-extracting archives which when run, will produce the working utilities LHA.EXE, PKZIP.EXE and PKUNZIP.EXE, along with a number of other files including comprehensive instructions on their use. Do yourself a favour and read the instructions!
It is good to put these working files in a directory that is in the PATH statement of your DOS environment, so that DOS can always find them. Many people have a special directory named UTILS or something similar, which is a hold-all for all these small, single file utility programs. Just make sure that particular directory is in your DOS path, then all the programs in that directory will be found when needed.
As for how to use these archiving programs; well, if you read the documentation you would know but if you forget you can type just the program name at the DOS prompt, e.g. LHA or PKZIP, and press the Enter key and you will see a screen full of instructions on its use.
I would suggest it is best to learn to use these utilities by working with them at the DOS prompt rather than through (say) Windows, and then later when you become proficient at using them you may like to try one of the archiving shells such as SHEZ.
Viruses in archives
One big concern I hear about is the possibility of members downloading
a virus with the files from the BBS. Firstly, let me stress that while it is possible for this to happen, the chances of any virus surviving the rigorous checking we undertake on every file that comes into the BBS, are very small.
Secondly, even if you did download a virus it would have absolutely no effect whatsoever on your machine, until you actually run the program that contained it. This being the case you may wish to treat self-extracting archives with a fair amount of caution. However, a virus contained in a program inside a ZIP or LZH file could not infect your system until you unarchived it and run the infected program.
To guard against that possibility you have the opportunity to run your favorite virus checking program on all programs before you run them, just to be sure in your own mind. However be assured that before you even see an archive on the BBS it has already been tested using two different antivirus programs.
I would suggest you obtain the latest versions of McAfee's virus checking and cleaning programs. Make these the target of your second download from the BBS. You will find them in files Area 1, named SCN_nnnx.LZH (where the nnnx stands for a particular version number) and once again, these should reside in your UTILS directory, or somewhere in your DOS path.
So with these utilities and the practice you get downloading them, you will be able to download, unarchive, scan and if necessary clean any viruses from your system. Go for it.
Reprinted from the June 1995 issue of PC Update, the magazine of Melbourne PC User Group, Australia
