Big Dummy's Guide To The Internet Part 23

Before, you saw how to use archie. From our example, you can see that some system administrators go a little berserk when naming files.

Fortunately, there's a way for you to rename the file as it's being transferred. Using our archie example, you'd type

get zterm-sys7-color-icons.hqx zterm.hqx

and hit enter. Instead of having to deal constantly with a file called zterm-sys7-color-icons.hqx, you'll now have one called, simply, zterm.hqx.

Those last three letters bring up something else: Many program files are compressed to save on s.p.a.ce and transmission time. In order to actually use them, you'll have to use an un-compress program on them first.

7.4 ODD LETTERS -- DECODING FILE ENDINGS

There are a wide variety of compression methods in use. You can tell which method was used by the last one to three letters at the end of a file. Here are some of the more common ones and what you'll need to un- compress the files they create (most of these decompression programs can be located through archie).

.txt or .TXT By itself, this means the file is a doc.u.ment, rather than a program.

.ps or .PS A PostScript doc.u.ment (in Adobe's page description language). You can print this file on any PostScript capable printer, or use a previewer, like GNU project's GhostScript.

.doc or .DOC Another common "extension" for doc.u.ments. No decompression is needed, unless it is followed by:

.Z This indicates a Unix compression method. To uncompress, type

uncompress filename.Z

and hit enter at your host system's command line. If the file is a compressed text file, you can read it online by instead typing

zcat filename.txt.Z |more

u16.zip is an MS-DOS program that will let you download such a file and uncompress it on your own computer. The Macintosh equivalent program is called MacCompress (use archie to find these).

.zip or .ZIP These indicate the file has been compressed with a common MS-DOS compression program, known as PKZIP (use archie to find PKZIP204.EXE). Many Unix systems will let you un-ZIP a file with a program called, well, unzip.

.gz A Unix version of ZIP. To uncompress, type

gunzip filename.gz

at your host system's command line.

.zoo or .ZOO A Unix and MS-DOS compression format. Use a program called zoo to uncompress

.Hqx or .hqx Mactintosh compression format. Requires the BinHex program.

.shar or Another Unix format. Use unshar to uncompress.

.Shar

.tar Another Unix format, often used to compress several related files into one large file. Most Unix systems will have a program called tar for "un-tarring" such files. Often, a "tarred" file will also be compressed with the gz method, so you first have to use uncompress and then tar.

.sit or .Sit A Mactinosh format that requires the StuffIt program.

.ARC Another MS-DOS format, which requires the use of the ARC or ARCE programs.

.LHZ Another MS-DOS format; requires the use of LHARC.

A few last words of caution: Check the size of a file before you get it. The Net moves data at phenomenal rates of speed. But that 500,000- byte file that gets transferred to your host system in a few seconds could take more than an hour or two to download to your computer if you're using a 2400-baud modem. Your host system may also have limits on the amount of bytes you can store online at any one time. Also, although it is really extremely unlikely you will ever get a file infected with a virus, if you plan to do much downloading over the Net, you'd be wise to invest in a good anti-viral program, just in case.

7.5 THE KEYBOARD CABAL

System administrators are like everybody else -- they try to make things easier for themselves. And when you sit in front of a keyboard all day, that can mean trying everything possible to reduce the number of keys you actually have to hit each day.

Unfortunately, that can make it difficult for the rest of us.

You've already read about bin and lost+found directories. Etc is another seemingly interesting directory that turns out to be another place to store files used by the ftp site itself. Again, nothing of any real interest.

Then, once you get into the actual file libraries, you'll find that in many cases, files will have such non-descriptive names as V1.1- AK.TXT. The best known example is probably a set of several hundred files known as RFCs, which provide the basic technical and organizational information on which much of the Internet is built.

These files can be found on many ftp sites, but always in a form such as RFC101.TXT, RFC102.TXT and so on, with no clue whatsoever as to what information they contain.

Fortunately, almost all ftp sites have a "Rosetta Stone" to help you decipher these names. Most will have a file named README (or some variant) that gives basic information about the system. Then, most directories will either have a similar README file or will have an index that does give brief descriptions of each file. These are usually the first file in a directory and often are in the form 00INDEX.TXT. Use the ftp command to get this file. You can then scan it online or download it to see which files you might be interested in.

Another file you will frequently see is called ls-lR.Z. This contains a listing of every file on the system, but without any descriptions (the name comes from the Unix command ls -lR, which gives you a listing of all the files in all your directories). The Z at the end means the file has been compressed, which means you will have to use a Unix un-compress command before you can read the file.

And finally, we have those system administrators who almost seem to delight in making things difficult -- the ones who take full advantage of Unix's ability to create absurdly long file names. On some FTP sites, you will see file names as long as 80 characters or so, full of capital letters, underscores and every other orthographic device that will make it almost impossible for you to type the file name correctly when you try to get it.

Your secret weapon here is the mget command. Just type mget, a s.p.a.ce, and the first five or six letters of the file name, followed by an asterisk, for example:

mget This_F*

The FTP site will ask you if you want to get the file that begins with that name. If there are several files that start that way, you might have to answer 'n' a few times, but it's still easier than trying to recreate a ludicrously long file name.

7.6 SOME INTERESTING FTP SITES

What follows is a list of some interesting ftp sites, arranged by category. With hundreds of ftp sites now on the Net, however, this list barely scratches the surface of what is available. Liberal use of archie will help you find specific files.

The times listed for each site are in Eastern time and represent the periods during which it is considered acceptable to connect.

AMIGA

ftp.uu.net Has Amiga programs in the systems/amiga directory.

Available 24 hours.

wuarchive.wustl.edu. Look in the pub/aminet directory.

Available 24 hours.

ATARI

atari.archive.umich.edu Find almost all the Atari files you'll ever need, in the atari directory.

7 p.m. - 7 a.m.

BOOKS

rtfm.mit.edu The pub/usenet/rec.arts.books directories has reading lists for various authors as well as lists of recommended bookstores in different cities. Unfortunately, this site uses incredibly long file names -- so long they may scroll off the end of your screen if you are using an MS-DOS or certain other computers. Even if you want just one of the files, it probably makes more sense to use mget than get.

This way, you will be asked on each file whether you want to get it; otherwise you may wind up frustrated because the system will keep telling you the file you want doesn't exist (since you may miss the end of its name due to the scrolling problem).

6 p.m. - 6 a.m.

mrcnext.cso.uiuc.edu Project Gutenberg is an effort to translate paper texts into electronic form. Already available are more than 100 t.i.tles, from works by Lewis Carrol to Mark Twain; from "A Tale of Two Cities" to "Son of Tarzan." Look in the /etext/etext92 and /etext/etext93 directories.