Part 2

People that share common interests are inclined to discuss their hobby or interest at every available opportunity. One modern way to aid in this exchange of information is by using a mailing list---usually an email address that redistributes all mail sent to it back out to a list of addresses. For example, the Sun Managers mailing list (of interest to people that administer computers manufactured by Sun) has the address [email protected]. Any mail sent to that address will "explode" out to each person named in a file maintained on a computer at Northwestern University.

Administrative tasks (sometimes referred to as administrivia) are often handled through other addresses, typically with the suffix -request. To continue the above, a request to be added to or deleted from the Sun Managers list should be sent to [email protected].

When in doubt, try to write to the -request version of a mailing list address first; the other people on the list aren't interested in your desire to be added or deleted, and can certainly do nothing to expedite your request. Often if the administrator of a list is busy (remember, this is all peripheral to real jobs and real work), many users find it necessary to ask again and again, often with harsher and harsher language, to be removed from a list. This does nothing more than waste traffic and bother everyone else receiving the messages. If, after a reasonable amount of time, you still haven't succeeded to be removed from a mailing list, write to the postmaster at that site and see if they can help.

Exercise caution when replying to a message sent by a mailing list. If you wish to respond to the author only, make sure that the only address you're replying to is that person, and not the entire list. Often messages of the sort "Yes, I agree with you completely!" will appear on a list, boring the daylights out of the other readers. Likewise, if you explicitly do want to send the message to the whole list, you'll save yourself some time by checking to make sure it's indeed headed to the whole list and not a single person.

A list of the currently available mailing lists is available in at least two places; the first is in a file on ftp.nisc.sri.com called interest-groups under the netinfo/ directory. It's updated fairly regularly, but is large (presently around 700K), so only get it every once in a while. The other list is maintained by Gene Spafford ([email protected]), and is posted in parts to the newsgroup news.lists semi-regularly. (Usenet News, for info on how to read that and other newsgroups.)

Listservs

On BITNET there's an automated system for maintaining discussion lists called the listserv. Rather than have an already harried and overworked human take care of additions and removals from a list, a program performs these and other tasks by responding to a set of user-driven commands.

Areas of interest are wide and varied---ETHICS-L deals with ethics in computing, while ADND-L has to do with a role-playing game. A full list of the available BITNET lists can be obtained by writing to [email protected] with a body containing the command

list global

However, be sparing in your use of this---see if it's already on your system somewhere. The reply is quite large.

The most fundamental command is subscribe. It will tell the listserv to add the sender to a specific list. The usage is

subscribe foo-l Your Real Name

It will respond with a message either saying that you've been added to the list, or that the request has been passed on to the system on which the list is actually maintained.

The mate to subscribe is, naturally, unsubscribe. It will remove a given address from a BITNET list. It, along with all other listserv commands, can be abbreviated---subscribe as sub, unsubscribe as unsub, etc. For a full list of the available listserv commands, write to [email protected], giving it the command help.

As an aside, there have been implementations of the listserv system for non-BITNET hosts (more specifically, Unix systems). One of the most complete is available on cs.bu.edu in the directory pub/listserv.

"I made this letter longer than usual because I lack the time to make it shorter." Pascal, Provincial Letters XVI

Anonymous FTP

FTP (File Transfer Protocol) is the primary method of transferring files over the Internet. On many systems, it's also the name of the program that implements the protocol. Given proper permission, it's possible to copy a file from a computer in South Africa to one in Los Angeles at very fast speeds (on the order of 5--10K per second). This normally requires either a user id on both systems or a special configuration set up by the system administrator(s).

There is a good way around this restriction---the anonymous FTP service. It essentially will let anyone in the world have access to a certain area of disk space in a non-threatening way. With this, people can make files publicly available with little hassle. Some systems have dedicated entire disks or even entire computers to maintaining extensive archives of source code and information. They include gatekeeper.dec.com (Digital), wuarchive.wustl.edu (Washington University in Saint Louis), and archive.cis.ohio-state.edu (The Ohio State University).

The process involves the "foreign" user (someone not on the system itself) creating an FTP connection and logging into the system as the user anonymous, with an arbitrary password:

Name (foo.site.com:you): anonymous Password: [email protected]

Custom and netiquette dictate that people respond to the Password: query with an email address so that the sites can track the level of FTP usage, if they desire. (Addresses for information on email addresses).

The speed of the transfer depends on the speed of the underlying link. A site that has a 9600bps SLIP connection will not get the same throughput as a system with a 56k leased line (The Physical Connection, for more on what kinds of connections can exist in a network). Also, the traffic of all other users on that link will affect performance. If there are thirty people all FTPing from one site simultaneously, the load on the system (in addition to the network connection) will degrade the overall throughput of the transfer.

FTP Etiquette

Lest we forget, the Internet is there for people to do work. People using the network and the systems on it are doing so for a purpose, whether it be research, development, whatever. Any heavy activity takes away from the overall performance of the network as a whole.

The effects of an FTP connection on a site and its link can vary; the general rule of thumb is that any extra traffic created detracts from the ability of that site's users to perform their tasks. To help be considerate of this, it's highly recommended that FTP sessions be held only after normal business hours for that site, preferably late at night. The possible effects of a large transfer will be less destructive at 2 a.m. than 2 p.m. Also, remember that if it's past dinner time in Maine, it's still early afternoon in California---think in terms of the current time at the site that's being visited, not of local time.

Basic Commands

While there have been many extensions to the various FTP clients out there, there is a de facto "standard" set that everyone expects to work. For more specific information, read the manual for your specific FTP program. This section will only skim the bare minimum of commands needed to operate an FTP session.

Creating the Connection

The actual command to use FTP will vary among operating systems; for the sake of clarity, we'll use FTP here, since it's the most general form.

There are two ways to connect to a system---using its hostname or its Internet number. Using the hostname is usually preferred. However, some sites aren't able to resolve hostnames properly, and have no alternative. We'll assume you're able to use hostnames for simplicity's sake. The form is

ftp somewhere.domain

Domains for help with reading and using domain names (in the example below, somewhere.domain is ftp.uu.net).

You must first know the name of the system you want to connect to. We'll use ftp.uu.net as an example. On your system, type:

ftp ftp.uu.net

(the actual syntax will vary depending on the type of system the connection's being made from). It will pause momentarily then respond with the message

Connected to ftp.uu.net.

and an initial prompt will appear:

220 uunet FTP server (Version 5.100 Mon Feb 11 17:13:28 EST 1991) ready. Name (ftp.uu.net:jm):

to which you should respond with anonymous:

220 uunet FTP server (Version 5.100 Mon Feb 11 17:13:28 EST 1991) ready. Name (ftp.uu.net:jm): anonymous

The system will then prompt you for a password; as noted previously, a good response is your email address:

331 Guest login ok, send ident as password. Password: [email protected] 230 Guest login ok, access restrictions apply. ftp>

The password itself will not echo. This is to protect a user's security when he or she is using a real account to FTP files between machines. Once you reach the ftp> prompt, you know you're logged in and ready to go.

Notice the ftp.uu.net:joe in the Name: prompt? That's another clue that anonymous FTP is special: FTP expects a normal user accounts to be used for transfers.

dir At the ftp> prompt, you can type a number of commands to perform various functions. One example is dir---it will list the files in the current directory. Continuing the example from above:

ftp> dir

200 PORT command successful. 150 Opening ASCII mode data connection for /bin/ls. total 3116 drwxr-xr-x 2 7 21 512 Nov 21 1988 .forward -rw-rw-r-- 1 7 11 0 Jun 23 1988 .hushlogin drwxrwxr-x 2 0 21 512 Jun 4 1990 Census drwxrwxr-x 2 0 120 512 Jan 8 09:36 ClariNet ... etc etc ... -rw-rw-r-- 1 7 14 42390 May 20 02:24 newthisweek.Z ... etc etc ... -rw-rw-r-- 1 7 14 2018887 May 21 01:01 uumap.tar.Z drwxrwxr-x 2 7 6 1024 May 11 10:58 uunet-info

226 Transfer complete. 5414 bytes received in 1.1 seconds (4.9 Kbytes/s) ftp>

The file newthisweek.Z was specifically included because we'll be using it later. Just for general information, it happens to be a listing of all of the files added to UUNET's archives during the past week.

The directory shown is on a machine running the Unix operating system---the dir command will produce different results on other operating systems (e.g. TOPS, VMS, et al.). Learning to recognize different formats will take some time. After a few weeks of traversing the Internet, it proves easier to see, for example, how large a file is on an operating system you're otherwise not acquainted with.

With many FTP implementations, it's also possible to take the output of dir and put it into a file on the local system with

ftp> dir n* outfilename

the contents of which can then be read outside of the live FTP connection; this is particularly useful for systems with very long directories (like ftp.uu.net). The above example would put the names of every file that begins with an n into the local file outfilename.

cd

At the beginning of an FTP session, the user is in a "top-level" directory. Most things are in directories below it (e.g. /pub). To change the current directory, one uses the cd command. To change to the directory pub, for example, one would type

ftp> cd pub

which would elicit the response

250 CWD command successful.

Meaning the "Change Working Directory" command (cd) worked properly. Moving "up" a directory is more system-specific---in Unix use the command cd .., and in VMS, cd [-].

get and put

The actual transfer is performed with the get and put commands. To get a file from the remote computer to the local system, the command takes the form:

ftp> get filename

where filename is the file on the remote system. Again using ftp.uu.net as an example, the file newthisweek.Z can be retrieved with

ftp> get newthisweek.Z 200 PORT command successful. 150 Opening ASCII mode data connection for newthisweek.Z (42390 bytes). 226 Transfer complete. local: newthisweek.Z remote: newthisweek.Z 42553 bytes received in 6.9 seconds (6 Kbytes/s) ftp>

The section below on using binary mode instead of ASCII will describe why this particular choice will result in a corrupt and subsequently unusable file.

If, for some reason, you want to save a file under a different name (e.g. your system can only have 14-character filenames, or can only have one dot in the name), you can specify what the local filename should be by providing get with an additional argument

ftp> get newthisweek.Z uunet-new

which will place the contents of the file newthisweek.Z in uunet-new on the local system.

The transfer works the other way, too. The put command will transfer a file from the local system to the remote system. If the permissions are set up for an FTP session to write to a remote directory, a file can be sent with

ftp> put filename

As with get, put will take a third argument, letting you specify a different name for the file on the remote system.

ASCII vs Binary

In the example above, the file newthisweek.Z was transferred, but supposedly not correctly. The reason is this: in a normal ASCII transfer (the default), certain characters are translated between systems, to help make text files more readable. However, when binary files (those containing non-ASCII characters) are transferred, this translation should not take place. One example is a binary program---a few changed characters can render it completely useless.

To avoid this problem, it's possible to be in one of two modes---ASCII or binary. In binary mode, the file isn't translated in any way. What's on the remote system is precisely what's received. The commands to go between the two modes are:

ftp> ascii 200 Type set to A. (Note the A, which signifies ASCII mode.)

ftp> binary 200 Type set to I. (Set to Image format, for pure binary transfers.)

Note that each command need only be done once to take effect; if the user types binary, all transfers in that session are done in binary mode (that is, unless ascii is typed later).

The transfer of newthisweek.Z will work if done as:

ftp> binary 200 Type set to I. ftp> get newthisweek.Z 200 PORT command successful. 150 Opening BINARY mode data connection for newthisweek.Z (42390 bytes). 226 Transfer complete. local: newthisweek.Z remote: newthisweek.Z 42390 bytes received in 7.2 seconds (5.8 Kbytes/s)

Note: The file size (42390) is different from that done in ASCII mode (42553) bytes; and the number 42390 matches the one in the listing of UUNET's top directory. We can be relatively sure that we've received the file without any problems.

mget and mput

The commands mget and mput allow for multiple file transfers using wildcards to get several files, or a whole set of files at once, rather than having to do it manually one by one. For example, to get all files that begin with the letter f, one would type

ftp> mget f*

Similarly, to put all of the local files that end with .c:

ftp> mput *.c

Rather than reiterate what's been written a hundred times before, consult a local manual for more information on wildcard matching (every DOS manual, for example, has a section on it).

Normally, FTP assumes a user wants to be prompted for every file in a mget or mput operation. You'll often need to get a whole set of files and not have each of them confirmed---you know they're all right. In that case, use the prompt command to turn the queries off.

ftp> prompt Interactive mode off.

Likewise, to turn it back on, the prompt command should simply be issued again.

Joe Granrose's List Monthly, Joe Granrose ([email protected]) posts to Usenet (Usenet News) an extensive list of sites offering anonymous FTP service. It's available in a number of ways:

The Usenet groups comp.misc and comp.sources.wanted

Anonymous FTP from pilot.njin.net [128.6.7.38], in /pub/ftp-list.

Write to [email protected] with a Subject: line of listserv-request and a message body of send help. Please don't bother Joe with your requests---the server will provide you with the list.

The archie Server archie is always in lowercase

A group of people at McGill University in Canada got together and created a query system called archie. It was originally formed to be a quick and easy way to scan the offerings of the many anonymous FTP sites that are maintained around the world. As time progressed, archie grew to include other valuable services as well.

The archie service is accessible through an interactive telnet session, email queries, and command-line and X-window clients. The email responses can be used along with FTPmail servers for those not on the Internet. (FTP-by-Mail Servers, for info on using FTPmail servers.)

Using archie Today

Currently, archie tracks the contents of over 800 anonymous FTP archive sites containing over a million files stored across the Internet. Collectively, these files represent well over 50 gigabytes of information, with new entries being added daily.

The archie server automatically updates the listing information from each site about once a month. This avoids constantly updating the databases, which could waste network resources, yet ensures that the information on each site's holdings is reasonably up to date.

To access archie interactively, telnet to one of the existing servers. {See Telnet, for notes on using the telnet program.} They include

archie.ans.net (New York, USA) archie.rutgers.edu (New Jersey, USA) archie.sura.net (Maryland, USA) archie.unl.edu (Nebraska, USA) archie.mcgill.ca (the first Archie server, in Canada) archie.funet.fi (Finland) archie.au (Australia) archie.doc.ic.ac.uk (Great Britain)

At the login: prompt of one of the servers, enter archie to log in. A greeting will be displayed, detailing information about ongoing work in the archie project; the user will be left at a archie> prompt, at which he may enter commands. Using help will yield instructions on using the prog command to make queries, set to control various aspects of the server's operation, et al. Type quit at the prompt to leave archie. Typing the query prog vine.tar.Z will yield a list of the systems that offer the source to the X-windows program vine; a piece of the information returned looks like:

Host ftp.uu.net (137.39.1.9) Last updated 10:30 7 Jan 1992

Location: /packages/X/contrib FILE rw-r--r-- 15548 Oct 8 20:29 vine.tar.Z

Host nic.funet.fi (128.214.6.100) Last updated 05:07 4 Jan 1992

Location: /pub/X11/contrib FILE rw-rw-r-- 15548 Nov 8 03:25 vine.tar.Z

archie Clients

There are two main-stream archie clients, one called (naturally enough) archie, the other xarchie (for X-Windows). They query the archie databases and yield a list of systems that have the requested file(s) available for anonymous FTP, without requiring an interactive session to the server. For example, to find the same information you tried with the server command prog, you could type

% archie vine.tar.Z Host athene.uni-paderborn.de Location: /local/X11/more_contrib FILE -rw-r--r-- 18854 Nov 15 1990 vine.tar.Z

Host emx.utexas.edu Location: /pub/mnt/source/games FILE -rw-r--r-- 12019 May 7 1988 vine.tar.Z

Host export.lcs.mit.edu Location: /contrib FILE -rw-r--r-- 15548 Oct 9 00:29 vine.tar.Z

Note that your system administrator may not have installed the archie clients yet; the source is available on each of the archie servers, in the directory archie/clients.

Using the X-windows client is much more intuitive---if it's installed, just read its man page and give it a whirl. It's essential for the networked desktop.

Mailing archie

Users limited to email connectivity to the Internet should send a message to the address [email protected] with the single word help in the body of the message. An email message will be returned explaining how to use the email archie server, along with the details of using FTPmail. Most of the commands offered by the telnet interface can be used with the mail server.

The whatis database

In addition to offering access to anonymous FTP listings, archie also permits access to the whatis description database. It includes the names and brief synopses for over 3,500 public domain software packages, datasets and informational documents located on the Internet.

Additional whatis databases are scheduled to be added in the future. Planned offerings include listings for the names and locations of online library catalog programs, the names of publicly accessible electronic mailing lists, compilations of Frequently Asked Questions lists, and archive sites for the most popular Usenet newsgroups. Suggestions for additional descriptions or locations databases are welcomed and should be sent to the archie developers at [email protected].

"Was f@"ur pl@"undern!" ("What a place to plunder!") Gebhard Leberecht Bl@"ucher

Usenet News

Original from: [email protected] (Chip Salzenberg) [Most recent change: 19 May 1991 by [email protected] (Gene Spafford)]

The first thing to understand about Usenet is that it is widely misunderstood. Every day on Usenet the "blind men and the elephant" phenomenon appears, in spades. In the opinion of the author, more flame wars (rabid arguments) arise because of a lack of understanding of the nature of Usenet than from any other source. And consider that such flame wars arise, of necessity, among people who are on Usenet. Imagine, then, how poorly understood Usenet must be by those outside!

No essay on the nature of Usenet can ignore the erroneous impressions held by many Usenet users. Therefore, this section will treat falsehoods first. Keep reading for truth. (Beauty, alas, is not relevant to Usenet.)

What Usenet Is

Usenet is the set of machines that exchange articles tagged with one or more universally-recognized labels, called newsgroups (or "groups" for short). (Note that the term newsgroup is correct, while area, base, board, bboard, conference, round table, SIG, etc. are incorrect. If you want to be understood, be accurate.)

The Diversity of Usenet

If the above definition of Usenet sounds vague, that's because it is. It is almost impossible to generalize over all Usenet sites in any non-trivial way. Usenet encompasses government agencies, large universities, high schools, businesses of all sizes, home computers of all descriptions, etc.

Every administrator controls his own site. No one has any real control over any site but his own. The administrator gets his power from the owner of the system he administers. As long as the owner is happy with the job the administrator is doing, he can do whatever he pleases, up to and including cutting off Usenet entirely. C'est la vie.

What Usenet Is Not

Usenet is not an organization. Usenet has no central authority. In fact, it has no central anything. There is a vague notion of "upstream" and "downstream" related to the direction of high-volume news flow. It follows that, to the extent that "upstream" sites decide what traffic they will carry for their "downstream" neighbors, that "upstream" sites have some influence on their neighbors. But such influence is usually easy to circumvent, and heavy-handed manipulation typically results in a backlash of resentment.

Usenet is not a democracy. A democracy can be loosely defined as "government of the people, by the people, for the people." However, as explained above, Usenet is not an organization, and only an organization can be run as a democracy. Even a democracy must be organized, for if it lacks a means of enforcing the peoples' wishes, then it may as well not exist.