Johns Hopkins Gazette: October 24, 1994


Hopkins in Cyberspace
By Mike Field

    Probably one of the greatest opportunities presented through
the Internet is the ability to exchange information on a
worldwide basis with others who share similar interests. One way
this can be accomplished is through e-mail. If you know the
Internet address of a colleague or friend, it is possible to
share daily, nearly instantaneous correspondence. Two researchers
working in tandem, for instance, can exchange observations and
ideas on an hourly basis if they choose to do so. 
    While such intensive, one-on-one correspondence can be
helpful in dealing with specialized problems or exploring a
specific idea, many Internet users want a broader, more
generalized approach. They look to the Net for new ideas and
input, for introductions to colleagues unknown to them and to
stay abreast with the latest developments in their field. For
these individuals, the best thing on the Net is discussion
groups, where like-minded individuals from all over the world can
gather to discuss everything from applied physics to zoology,
Kabuki theater to molecular genetics.
    Most of these discussion groups rely on a program called
LISTSERV, which enables members from all over the world to
participate in--or just follow--threads of conversation that will
often continue for weeks, even months. To make the most of one of
these discussion groups it is helpful to understand how LISTSERV
works and to master a few basic commands.
    The idea behind LISTSERV is fairly simple. Instead of
requiring members in a discussion group to mail their comments to
everyone on the list (which could run to over hundreds of
addresses), LISTSERV resides at one central source. Members of
the list send all their correspondence there; LISTSERV in turn,
"explodes" each message by copying it and sending it to every
member of the list. Because LISTSERV uses an e-mail format,
sending messages to the list is no more difficult than sending 
e-mail; furthermore, even individuals with the lowest level of
Internet access (basic e-mail) can participate.
    Although the idea is deceptively simple, there are a few
complications that seem to confound all but the most experienced
Internet traveler. In essence, LISTSERV can be thought of as a
giant relay station that receives your message and echoes it
across the world to every member on the list (including you).
Since it does this automatically_and without thinking_it is easy
to imagine what happens when the poor hapless discussion group
member decides to leave the list. "Thank you very much, but I no
longer wish to subscribe to the list," he or she writes, only to
receive the message back later that day (as does everyone else on
the list). "No, really, I no longer want to be a member," goes
the next message, which of course comes back again.
    "LOOK! Stop sending me messages!" comes the third message,
and so on until some kindly soul in the group takes the time to
contact the person and explain how to leave the list.
    Leaving a LISTSERV list, or for that matter joining or
taking a temporary leave of absence while you're on vacation, is
a relatively simple matter. It depends, however, on members
understanding that there is not one but two addresses for each
LISTSERV group. The first, known as the list address, is where
you send comments to have them "exploded" throughout the list.
The second, called the LISTSERV address, is where you send
commands (such as UNSUBSCRIBE, which will remove you from the
list). 
    Luckily, if you know one address, you can easily figure out
the other: Both are identical after the @. Say, for instance,
you've heard of a LISTSERV discussion group concerning Hopkins
Lacrosse. We'll say this fictional group can be found at
H-Lacro@jhucomp.jhu.edu. Knowing this, and wanting to join in on
the discussion, you would simply send a message to
LISTSERV@jhucomp.jhu.edu that reads, in the body of the letter,
SUBSCRIBE H-Lacro (your full name). Finding the conversation on
the list exceedingly dull, you could later leave the list by
mailing the command UNSUBSCRIBE H-Lacro (your full name) to
LISTSERV@jhucomp.jhu.edu. It's that simple.
    Yet LISTSERV has some additional features that users tend to
overlook. For instance, on many groups the messages that come
through LISTSERV each day are automatically saved and indexed. To
get a copy of our fictional lacrosse discussion group index you
would again send to the LISTSERV address with the command INDEX
H-Lacro F=MAIL. In this instance, the F=MAIL component of the
command is telling LISTSERV to send the file in an e-mail format.
    If there was a discussion listed in the index you wished to
retrieve you would then use the GET command, again sending it to
the LISTSERV address. Say you came across a file discussing last
year's game against Loyola, titled LOYOLA 1993. In order to
retrieve that file you would send the command GET LOYOLA 1993
F=MAIL. Mastering INDEX, GET, SUBSCRIBE and UNSUBSCRIBE can
enable you to travel to all kinds of informational sources on the
Internet and meet people who share your interests from all over
the world.

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