which would copy file1 to file2 (or overwrite file2 with file1).

ls This command, when followed by enter, tells you what"s in the directory, similar to the DOS dir command, except in alphabetical order.

ls | more

will stop the listing every 24 lines -- handy if there are a lot of things in the directory. The basic ls command does not list "hidden" files, such as the .login file that controls how your system interacts with Unix. To see these files, type

ls -a or ls -a | more

ls -l will tell you the size of each file in bytes and tell you when each was created or modified.

mv Similar to the MS-DOS rename command.

mv file1 file2

will rename file1 as file2, The command can also be used to move files between directories.

mv file1 News

would move file1 to your News directory.

rm Deletes a file. Type

rm filename

and hit enter (but beware: when you hit enter, it"s gone for good).

WILDCARDS: When searching for, copying or deleting files, you can use "wildcards" if you are not sure of the file"s exact name.

ls man*

would find the following files:

manual, manual.txt, man-o-man.

Use a question mark when you"re sure about all but one or two characters.

For example,

ls man?

would find a file called mane, but not one called manual.

2.7 WHEN THINGS GO WRONG

* You send a message but get back an ominous looking message from MAILER-DAEMON containing up to several dozen lines of computerese followed by your message.

Somewhere in those lines you can often find a clue to what went wrong. You might have made a mistake in spelling the e-mail address.

The site to which you"re sending mail might have been down for maintenance or a problem. You may have used the wrong "translation" for mail to a non-Internet network.

* You call up your host system"s text editor to write a message or reply to one and can"t seem to get out.

If it"s emacs, try control-X, control-C (in other words, hit your control key and your X key at the same time, followed by control and C).

If worse comes to worse, you can hang up.

* In elm, you accidentally hit the D key for a message you want to save.

Type the number of the message, hit enter and then U, which will "un-delete" the message. This works only before you exit Elm; once you quit, the message is gone.

* You try to upload an ASCII message you"ve written on your own computer into a message you"re preparing in Elm or Pine and you get a lot of left brackets, capital Ms, Ks and Ls and some funny-looking characters.

Believe it or not, your message will actually wind up looking fine; all that garbage is temporary and reflects the problems some Unix text processors have with ASCII uploads. But it will take much longer for your upload to finish. One way to deal with this is to call up the simple mail program, which will not produce any weird characters when you upload a text file into a message. Another way (which is better if your prepared message is a response to somebody"s mail), is to create a text file on your host system with cat, for example,

cat>file

and then upload your text into that. Then, in elm or pine, you can insert the message with a simple command (control-R in pine, for example); only this time you won"t see all that extraneous stuff.

* You haven"t cleared out your Elm mailbox in awhile, and you accidentally hit "y" when you meant to hit "n" (or vice-versa) when exiting and now all your messages have disappeared. Look in your News directory (at the command line, type: cd News) for a file called recieved. Those are all your messages. Unfortunately, there"s no way to get them back into your Elm mailbox -- you"ll have to download the file or read it online.

Chapter 3: USENET I

3.1 THE GLOBAL WATERING HOLE

Imagine a conversation carried out over a period of hours and days, as if people were leaving messages and responses on a bulletin board. Or imagine the electronic equivalent of a radio talk show where everybody can put their two cents in and no one is ever on hold.

Unlike e-mail, which is usually "one-to-one," Usenet is "many-to- many." Usenet is the international meeting place, where people gather to meet their friends, discuss the day"s events, keep up with computer trends or talk about whatever"s on their mind. Jumping into a Usenet discussion can be a liberating experience. n.o.body knows what you look or sound like, how old you are, what your background is. You"re judged solely on your words, your ability to make a point.

To many people, Usenet IS the Net. In fact, it is often confused with Internet. But it is a totally separate system. All Internet sites CAN carry Usenet, but so do many non-Internet sites, from sophisticated Unix machines to old XT clones and Apple IIs.

Technically, Usenet messages are shipped around the world, from host system to host system, using one of several specific Net protocols. Your host system stores all of its Usenet messages in one place, which everybody with an account on the system can access. That way, no matter how many people actually read a given message, each host system has to store only one copy of it. Many host systems "talk"

with several others regularly in case one or another of their links goes down for some reason. When two host systems connect, they basically compare notes on which Usenet messages they already have. Any that one is missing the other then transmits, and vice-versa. Because they are computers, they don"t mind running through thousands, even millions, of these comparisons every day.

Yes, millions. For Usenet is huge. Every day, Usenet users pump upwards of 40 million characters a day into the system -- roughly the equivalent of volumes A-G of the Encyclopedia Britannica. Obviously, n.o.body could possibly keep up with this immense flow of messages. Let"s look at how to find conferences and discussions of interest to you.

The basic building block of Usenet is the newsgroup, which is a collection of messages with a related theme (on other networks, these would be called conferences, forums, bboards or special-interest groups). There are now more than 5,000 of these newsgroups, in several diferent languages, covering everything from art to zoology, from science fiction to South Africa.

Some public-access systems, typically the ones that work through menus, try to make it easier by dividing Usenet into several broad categories. Choose one of those and you"re given a list of newsgroups in that category. Then select the newsgroup you"re interested in and start reading.

Other systems let you compile your own "reading list" so that you only see messages in conferences you want. In both cases, conferences are arranged in a particular hierarchy devised in the early 1980s.

Newsgroup names start with one of a series of broad topic names. For example, newsgroups beginning with "comp." are about particular computer- related topics. These broad topics are followed by a series of more focused topics (so that "comp.unix" groups are limited to discussion about Unix). The main hierarchies are:

bionet Research biology bit.listserv Conferences originating as Bitnet mailing lists biz Business comp Computers and related subjects misc Discussions that don"t fit anywhere else news News about Usenet itself rec Hobbies, games and recreation sci Science other than research biology soc "Social" groups, often ethnically related talk Politics and related topics alt Controversial or unusual topics; not carried by all sites

In addition, many host systems carry newsgroups for a particular city, state or region. For example, ne.housing is a newsgroup where New Englanders look for apartments. A growing number also carry K12 newsgroups, which are aimed at elementary and secondary teachers and students. And a number of sites carry clari newsgroups, which is actually a commercial service consisting of wire-service stories and a unique online computer news service (more on this in chapter 10).

3.2 NAVIGATING USENET WITH nn

How do you dive right in? As mentioned, on some systems, it"s all done through menus -- you just keep choosing from a list of choices until you get to the newsgroup you want and then hit the "read" command. On Unix systems, however, you will have to use a "newsreader" program. Two of the more common ones are known as rn (for "read news") and nn (for "no news" -- because it"s supposed to be simpler to use).

For beginners, nn may be the better choice because it works with menus -- you get a list of articles in a given newsgroup and then you choose which ones you want to see. To try it out, connect to your host system and, at the command line, type

nn news.announce.newusers