Big Dummy's Guide To The Internet - LightNovelsOnl.com
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ftp.unt.edu The antivirus directory has anti-virus programs for MS- DOS and Macintosh computers.
7 p.m. - 7 a.m.
WEATHER
wuarchive.wustl.edu The /multimedia/images/wx directory contains GIF weather images of North America. Files are updated hourly and take this general form: CV100222. The first two letters tell the type of file: CV means it is a visible-light photo taken by a weather satellite. CI images are similar, but use infrared light. Both these are in black and white. Files that begin with SA are color radar maps of the U.S. that show severe weather patterns but also fronts and temperatures in major cities. The numbers indicate the date and time (in GMT - five hours ahead of EST) of the image: the first two numbers represent the month, the next two the date, the last two the hour. The file WXKEY.GIF explains the various symbols in SA files.
7.7 ncftp -- NOW YOU TELL ME!
If you're lucky, the people who run your host system or public- access site have installed a program called ncftp, which takes some of the edges off the ftp process.
For starters, when you use ncftp instead of plain old ftp, you no longer have to worry about misspelling "anonymous" when you connect. The program does it for you. And once you're in, instead of getting line after line filled with dashes, x's, r's and d's, you only get listings of the files or directories themselves (if you're used to MS-DOS, the display you get will be very similar to that produced by the dir/w command). The program even creates a list of the ftp sites you've used most recently, so you can pick from that list, instead of trying to remember some incredibly complex ftp site name.
Launching the program, a.s.suming your site has it, is easy. At the command prompt, type
ncftp sitename
where "sitename" is the site you want to reach (alternately, you could type just ncftp and then use its open command). Once connected, you can use the same ftp commands you've become used to, such as ls, get and mget. Entries that end in a / are directories to which you can switch with cd; others are files you can get. A couple of useful ncftp commands include type, which lets you change the type of file transfer (from ASCII to binary for example) and size, which lets you see how large a file is before you get it, for example
size declaration.txt
would tell you how large the declaration.txt file is before you get it.
When you say "bye" to disconnect from a site, ncftp remembers the last directory you were in, so that the next time you connect to the site, you are put back into that directory automatically. If you type
help
you'll get a list of files you can read to extend the power of the program even further.
7.8 PROJECT GUTENBERG -- ELECTRONIC BOOKS
Project Gutenberg, coordinated by Michael Hart, has a fairly ambitious goal: to make more than 10,000 books and other doc.u.ments available electronically by the year 2001. In 1993, the project uploaded an average of four books a month to its ftp sites; in 1994, they hope to double the pace.
Begun in 1971, the project already maintains a "library" of hundreds of books and stories, from Aesop's Fables to "Through the Looking Gla.s.s"
available for the taking. It also has a growing number of current- affairs doc.u.ments, such as the CIA's annual "World Factbook" almanac.
Besides nptn.org, Project Gutenberg texts can be retrieved from mrcnext.cso.uiuc.edu in the etext directory.
7.9 WHEN THINGS GO WRONG
* You get a "host unavailable" message. The ftp site is down for some reason.
Try again later.
* You get a "host unknown" message.
Check your spelling of the site name.
* You misspell "anonymous" when logging in and get a message telling you a pa.s.sword is required for whatever you typed in.
Type something in, hit enter, type bye, hit enter, and try again.
Alternately, try typing "ftp" instead of "anonymous." It will work on a surprising number of sites. Or just use ncftp, if your site has it, and never worry about this again.
7.10 FYI
Liberal use of archie will help you find specific files or doc.u.ments. For information on new or interesting ftp sites, try the comp.archives newsgroup on Usenet. You can also look in the comp.misc, comp.sources.wanted or news.answers newsgroups on Usenet for lists of ftp sites posted every month by Tom Czarnik and Jon Granrose.
The comp.archives newsgroup carries news of new ftp sites and interesting new files on existing sites.
In the comp.virus newsgroup on Usenet, look for postings that list ftp sites carrying anti-viral software for Amiga, MS-DOS, Macintosh, Atari and other computers.
The comp.sys.ibm.pc.digest and comp.sys.mac.digest newsgroups provide information about new MS-DOS and Macintosh programs as well as answers to questions from users of those computers.
Chapter 8: GOPHERS, WAISs AND THE WORLD-WIDE WEB
8.1. GOPHERS
Even with tools like Hytelnet and archie, telnet and ftp can still be frustrating. There are all those telnet and ftp addresses to remember. Telnet services often have their own unique commands. And, oh, those weird directory and file names!
But now that the Net has become a rich repository of information, people are developing ways to make it far easier to find and retrieve information and files. Gophers and Wide-Area Information Servers (WAISs) are two services that could ultimately make the Internet as easy to navigate as commercial networks such as CompuServe or Prodigy.
Both gophers and WAISs essentially take a request for information and then scan the Net for it, so you don't have to. Both also work through menus -- instead of typing in some long sequence of characters, you just move a cursor to your choice and hit enter. Gophers even let you select files and programs from ftp sites this way.
Let's first look at gophers (named for the official mascot of the University of Minnesota, where the system was developed).
Many public-access sites now have gophers online. To use one, type
gopher
at the command prompt and hit enter. If you know your site does not have a gopher, or if nothing happens when you type that, telnet to
consultant.micro.umn.edu
At the log-in prompt, type
gopher
and hit enter. You'll be asked what type of terminal emulation you're using, after which you'll see something like this:
Internet Gopher Information Client v1.03
Root gopher server: gopher.micro.umn.edu
--> 1. Information About Gopher/ 2. Computer Information/ 3. Discussion Groups/ 4. Fun & Games/ 5. Internet file server (ftp) sites/ 6. Libraries/ 7. News/ 8. Other Gopher and Information Servers/ 9. Phone Books/ 10. Search lots of places at the U of M 11. University of Minnesota Campus Information/
Press ? for Help, q to Quit, u to go up a menu Page: 1/1
a.s.suming you're using VT100 or some other VT emulation, you'll be able to move among the choices with your up and down arrow keys. When you have your cursor on an entry that looks interesting, just hit enter, and you'll either get a new menu of choices, a database entry form, or a text file, depending on what the menu entry is linked to (more on how to tell which you'll get in a moment).
Gophers are great for exploring the resources of the Net. Just keep making choices to see what pops up. Play with it; see where it takes you. Some choices will be doc.u.ments. When you read one of these and either come to the end or hit a lower-case q to quit reading it, you'll be given the choice of saving a copy to your home directory or e-mailing it to yourself. Other choices are simple databases that let you enter a word to look for in a particular database. To get back to where you started on a gopher, hit your u key at a menu prompt, which will move you back "up" through the gopher menu structure (much like "cd .." in ftp).
Notice that one of your choices above is "Internet file server (ftp) sites." Choose this, and you'll be connected to a modified archie program -- an archie with a difference. When you search for a file through a gopher archie, you'll get a menu of sites that have the file you're looking for, just as with the old archie. Only now, instead of having to write down or remember an ftp address and directory, all you have to do is position the cursor next to one of the numbers in the menu and hit enter. You'll be connected to the ftp site, from which you can then choose the file you want. This time, move the cursor to the file you want and hit a lower-case s. You'll be asked for a name in your home directory to use for the file, after which the file will be copied to your home system. Unfortunately, this file-transfer process does not yet work with all public-access sites for computer programs and compressed files. If it doesn't work with yours, you'll have to get the file the old-fas.h.i.+oned way, via anonymous ftp.
In addition to ftp sites, there are hundreds of databases and libraries around the world accessible through gophers. There is not yet a common gopher interface for library catalogs, so be prepared to follow the online directions more closely when you use gopher to connect to one.
Gopher menu entries that end in a / are gateways to another menu of options. Entries that end in a period are text, graphics or program files, which you can retrieve to your home directory (or e-mail to yourself or to somebody else). A line that ends in or
