1 PROJECT ATHENA NEWSLETTER FEBRUARY 4, 1985 VOLUME 2, NO. 2 Copyright (C) 1985 Massachusetts Institute of Technology 2 EDITORIAL POLICY The Project Athena Newsletter is the official publication of Project Athena, a five-year experiment in the use of computer technologies to improve the education of students at the Massachusetts Institute of Technology. The Newsletter prints articles of interest to members of the MIT community who participate, or who are interested, in the Project. These articles present the general purpose, philosophy, technical development, and direction of Project Athena, and specific news items about Project Athena facilities and projects. We encourage article submissions from the community and publish appropriate contributions whenever possible. If you have any comments or questions on the newsletter-- Contact: Will Doherty Editor Project Athena Newsletter MIT E40-426 Cambridge, MA 02139 (617)253-0110 DRAFT DRAFT DRAFT PROJECT ATHENA NEWSLETTER FEBRUARY 4, 1985 VOLUME 2, NO. 2 1 Building 6 and 2 Clusters Open Eva Tervo, Operations Coordinator On January 25, two new clusters joined the Athena system. Building 6-218M contains 16 IBM PC/XT's connected to two Digital VAX 11/750's in Building E40. Supplementing these terminals are 8 IBM PC/AT's running standalone. Building 2 has 8 XT's that run as terminals on a Digital VAX 11/750, also located in Building E40. Output from both 6-218M and 2-225 will print on an LN01 laser printer located in 6-218M. 6-218M is in the building 6 stairwell between the second and Project Athena Newsletter 1 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 third floors. It has two doors, one in the stairwell and one in an interior corridor. The stairwell door is the main front door. The corridor door is an emergency exit only. 2 Students: Subjects for Spring 1985 Ed Moriarty, Course Consultant This spring, 37 subjects with a total of about 1750 students will use the Athena system. About 20 of these subjects are new to Athena. The number of students for the Spring term will be about double that of the Fall term. We have added two terminal rooms (6-218M and 2-225) and three more Digital VAX 11/750's. The table on the following page shows which subjects are tentatively assigned to which machines. Project Athena Newsletter 2 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 2.1 Athena Student Registration We have revised the process by which students get Athena accounts, called "registration." The overall process is as follows: 1. Students who do not already have an Athena username MUST first reserve an Athena username by visiting a special registration terminal. 2. All students then submit a form that contains his or her username and full name to their instructor or TA. 3. The "account administrator" for the subject then creates accounts on the machines used by the subject for the students who submitted their usernames. 2.2 Step 1: Reserving an Athena Username Students registering for one of the subjects listed in the table below who do not already have an Athena username (also referred Project Athena Newsletter 3 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 to as a "login id") will first have reserve a username. Go to one of the Athena Registration Terminals located in either the W20 Student Center fifth floor library (6 terminals) or in 66-080 (2 terminals). The registration program asks for your name and MIT ID number. It then looks for you in a database to see if you have registered for the spring term. If the database indicates that you have registered, the registration program will allow you to reserve a username and establish an initial password. If the registration program does not locate you in the database (because of mispelled entries in the database, late registration, etc.), then you should contact Athena account administration staff in the carrel across from E40-442C, between 1pm and 5pm, with proof that you are currently enrolled as an MIT student (an MIT ID with current sticker or a reasonable facsimile). They will make sure that, if you are a registered student you get an Athena username. Project Athena Newsletter 4 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 You must reserve your username before you give it to your instructor. Otherwise, the subject's account administrator will not be able to set up an account for you. 2.3 Step 2: The Registration Form On the first day your class meets, you will receive an instruction sheet that explains how to reserve a username. You will also receive a Registration Form. After you have reserved a username, simply fill out the form and return it to the instructor. You will not get a working account until you reserve a username and submit the form. 2.4 Step 3: Account Creation Your account administrator (instructor or TA) will take the registration form you gave him/her, check to make sure you have enrolled in the subject, and then create an account for you on the machine your subject will use. This may take several days. See your account administrator for information on when your Project Athena Newsletter 5 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 account will be available. Tentative Project Athena Allocation of Courses to Machines for the Spring '85 Term As of January 14, 1985 ----------------------------------------------------------------- Bldg 1 Machine Subject Number zeus (server) hera 1.03 demeter 1.12, 2.01 ares poseidon 2.671, 2.672, 13.901, 16.62x hades 1.542, 2.01 ----------------------------------------------------------------- Bldg 2 Machine Subject Number Project Athena Newsletter 6 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 andromache 5.32, 18.330, 18.336 ----------------------------------------------------------------- Bldg 4 Machine Subject Number athena 11.481, 13.76, 22.44j, Tech & Policy Seminar ----------------------------------------------------------------- Bldg 6 Machine Subject Number PC/AT's 18.06, 8.22 odysseus 14.01, 14.02, 17.401 agamemnon 14.01, 14.02, 21.780 ----------------------------------------------------------------- Bldg 11 Machine Subject Number apollo (server) charon Project Athena Newsletter 7 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 aphrodite 13.40 artemis 12.21, 12.502 atlas 13.40 ----------------------------------------------------------------- Bldg 38 Machine Subject Number trillian (server) slartibartfast 6.013, 6.014, 16.02, 16.04 zarquon 3.185, 6.013, 6.014, hst090 hactar 6.013, 6.014, 16.02, hst090 prak 21.232 ----------------------------------------------------------------- Bldg 66 Machine Subject Number clio (server) mnemosyne 1.00, 2.10 erato 1.00, 2.10 calliope 1.00, 2.10 Project Athena Newsletter 8 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 polyhymnia 1.00, 2.10 urania 10.01 euterpe 10.01, 17.487 ----------------------------------------------------------------- Bldg W20 ringworld (server) louiswu nessus speaker Student accounts for those who have completed teela courses using Athena equipment prill ----------------------------------------------------------------- 3 Consulting Coverage Spring Term Mike Candan, Head Student Consultant Project Athena Newsletter 9 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 3.1 Walk-In Consulting Centers Our walk-in consulting centers are located in the most heavily-used Athena clusters: 1-142, 11-113, 66-080, and the Student Center (W20) fifth floor. Students consultants will be staffing our walk-in consulting centers primarily during the afternoons and evenings this term. The consultants will not be on duty during dinner hours (5-7 p.m.), Friday and Saturday nights, and the early morning hours (midnight to about 10 a.m.). We'll be adjusting the schedule slightly to provide the best coverage possible as the term progresses. A schedule will be posted in all the Athena clusters. 3.2 Phone Consulting You can also try calling the Consultant's Office at (25)3-4435. Although we do not guarantee coverage at every hour, we will be trying to answer the phone during the late morning to 4 p.m. and Project Athena Newsletter 10 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 evening hours on weekdays, and on weekend afternoons. 4 Athena Survival Courses Cecilia d'Oliveira, User Services Manager First-time students in Athena-sponsored courses should consider attending a two-hour introduction to Athena entitled ``Athena Survival.'' Scheduled several times during the first two weeks of the term, the Survival course will teach the basics of the system, such as how to login, use the text editor, send mail, and run programs. Anyone who plans to attend a Survival course should obtain a "starter set" of the Athena Essential series of documentation and review it prior to the session. Students in Athena-supported courses will receive this "starter set" documentation at the first class of the term. Otherwise, you can obtain the documentation from the IS Publications Office in 11-209 weekdays Project Athena Newsletter 11 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 from 11am to 3pm, or in any Athena terminal cluster. If you feel you need more explanation than the documentation provides, you should attend one of the Survival courses. The Survival courses will cover what is in the Essential documentation. The Survival courses are primarily intended for student, but they will be open to anyone else who wants to attend on a first come, first serve basis. Here is the Survival course schedule. Survivals may be offered later in the term if there is sufficient demand. If your schedule permits, we encourage you to attend one of the sessions offered in 34-101, because more people can be seated there comfortably. ----------------------------------------------------------------- Date Time Location Wed, 2/6 6-8PM 34-101 Thurs, 2/7 9-11AM 1-390 Project Athena Newsletter 12 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 Thurs, 2/7 6-8PM 34-101 Fri, 2/8 10AM-noon 1-390 Mon, 2/11 1:30-3:30PM 34-101 Wed, 2/13 3-5PM 34-101 ----------------------------------------------------------------- 5 No W20 Dial-Up Service There is currently no dial-up access to any W20 host. There are no plans to provide dial-up service to W20. 6 Consultant's Corner: The History Mechanism Win Treese, Student Consultant Staff The history mechanism is one of the most useful parts of the C Project Athena Newsletter 13 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 shell. (The C shell is the piece of software that interprets the commands that you type on Project Athena machines.) The history mechanism makes it possible for you to repeat commands that you have already executed, to reuse arguments such as filenames from previous commands, or to fix typing errors, all quickly and easily without having to retype the commands over again. 6.1 The History List The C shell maintains a list of commands that you have executed, called the ``history list.'' The shell variable history, usually set-up in the .cshrc file in your home directory, specifies the length of the history list. The .cshrc file supplied by Project Athena sets the history variable to 40, which means that your forty most recent commands are in the list. You can see this list by typing history to the shell. For example, if the history variable is set to 5, you might see (what you should type is shown in bold face): Project Athena Newsletter 14 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 % history 7 emacs myfile 8 talk fakeuser 9 date 10 diff thisfile thatfile 11 history % We will use this short history in examples later in this article. 6.2 Re-Executing Previous Commands When you want to make use of a previous command in the history list, you signal the fact with the character !. This ! is called the "history substitution" character because it tells the shell you want to substitute some historical text for parts of the command to come. You can put the ! anywhere in a command line. When you type a command line with a history substitution, the C shell echos the command line as you type it, then prints the command line again Project Athena Newsletter 15 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 with the history substitutions expanded to their actual values. This happens before the C shell executes the command line, so you can see exactly what commands the C shell executes. The simplest case is the command !!, which runs the previous command again; for example: % pwd /mit/a/u/auser % !! pwd /mit/a/u/auser % You can repeat other previous commands by specifying: - the ``event number'' of the desired command line relative to the current command line, or - the event number of the desired command line, or - the first few letters of the initial command name in the desired command line Project Athena Newsletter 16 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 Thus, using the history list shown above as the example, you would execute the command date again by typing: - !-3, since it is the third most recent command, or - !9, since its event number is 9, or - !da, since da is a unique prefix for this command Your screen would appear as follows: % !-3 date Mon Feb 4 12:00 EST 1985 % !9 date Mon Feb 4 12:00 EST 1985 % !da Mon Feb 4 12:00 EST 1985 In general, you need only indicate enough letters to uniquely specify the string you want in the most recent command with that prefix. If you typed !d, the shell would execute diff thisfile thatfile again instead of date. Project Athena Newsletter 17 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 6.3 Substituting Parts of Previous Commands It is also possible to select a particular word from a previous command line. (A "word" is a string of characters separated by spaces. For example, in the command chmod 777 myfile, the words are: chmod, 777, and myfile.) These words are numbered beginning with 0, which is usually the name of the command. Word number 1 is the first argument, and so on. You select a particular word using a : (colon) after the event number, followed by the number of the word. For example, to edit the file thisfile from command line 10 in the history example above, you could type: % emacs !10:1 emacs thisfile and then Emacs would run with file thisfile. There are several other ways to pick a particular word. You can find more of these substitutions in parts of the Unix manuals. See the last paragraph of this article to find out more. Project Athena Newsletter 18 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 After you select a word using the word designators, you may use several "modifiers" to it. With these, you can substitute one string for another, alter filenames, and so on. To make a substitution, use s/oldstring/newstring as in: % !di:s/file/prog/ diff thisprog thatfile { no output would indicate that thisprog and thatfile are id % emacs !10:1:s/file/prog/ emacs thisprog and Emacs would run with file thisprog. The first example changes the command line diff thisfile thatfile to diff thisprog thatfile and the second takes word 1 from event number 10, substitutes the string prog for file, and uses the result as an argument to emacs. A shorthand notation for the substitution command uses the up-arrow character ^. When a line begins with a ^, the history Project Athena Newsletter 19 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 mechanism treats it as a substitution, with the original and replacement strings separated by another ^ character. For example, % ls /usr/unspported /usr/unspported not found % ^spp^supp ls /usr/unsupported { a directory listing of /usr/unsupported would print here } In this case, we use the ^ to correct the spelling of unspported in the previous command line. Another useful option is t, which strips the leading parts of the pathname and leaves only the actual name of the file. Thus, % ls /usr/unsupported/kermit /usr/unsupported/kermit not found % ls !!:1:t ls kermit { list of contents of directory kermit under the current dir Here the second command line takes the file name from the first Project Athena Newsletter 20 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 argument of the previous command. 6.4 For More Information You can find more information about the history mechanism by looking at the man page for csh (the C shell) under "History Substitution." Do this online by typing man csh, or look in the Athena Unix Commands manual under csh. The document An Introduction to the C Shell also describes the history mechanism in its section 2.3. This is available separately, or as part of the Athena Unix Users Guide. References copies of all documents are available in each Athena cluster. They can be also be purchased from the IS Publications Office in 11-209. Project Athena Newsletter 21 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 7 Newsletter Deadlines The deadline for submission of articles and article ideas for the March 4, 1985 issue is 5pm on Friday, February 15. The deadline for submission of articles and article ideas for the April 1, 1985 issue is 5pm on Friday, March 15. Project Athena Newsletter 22 Volume 2, No. 2 2/4/85 Project Athena Newsletter 2/4/85 Table of Contents 1 Building 6 and 2 Clusters Open 1 2 Students: Subjects for Spring 1985 2 2.1 Athena Student Registration 3 2.2 Step 1: Reserving an Athena Username 3 2.3 Step 2: The Registration Form 5 2.4 Step 3: Account Creation 5 3 Consulting Coverage Spring Term 9 3.1 Walk-In Consulting Centers 10 3.2 Phone Consulting 10 4 Athena Survival Courses 11 5 No W20 Dial-Up Service 13 6 Consultant's Corner: The History Mechanism 13 6.1 The History List 14 6.2 Re-Executing Previous Commands 15 6.3 Substituting Parts of Previous Commands 18 6.4 For More Information 21 7 Newsletter Deadlines 22 Project Athena Newsletter i Volume 2, No. 2