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A ROUGH GUIDE TO THE SHELL
KNOWLEDGE BASES FOR THE ELITE, ARCADE GAMES FOR THE MASSES.
PERL & SHELL BUILT IN VARIABLES
EXAMPLE ONE: A LOTTERY SCRIPT
EXAMPLE TWO: DYNAMIC HTML PAGES

A ROUGH GUIDE TO THE SHELL

Next |End Q: What is the Shell? A: The 'Shell' started out as an intereactive Job Control Language. In the days of punched card computing the design of Job Control Language (JCL) was an intractable problem, with features being added in an ad hoc manner as new hardware and software became available. The 'shell' acted as the user interface to the operating system, and this was achieved by either typing commands at the terminal, or running canned scripts to perform repeated jobs. Q: How old is the shell, and why the name ? A: Intereactive computing started in the early 1950s with the Massachussetts Institute of Technology's project MAC (Multiple Access Computing). Telex machines were connected directly to computers. Offline work could be done by preparing paper tape, via a keyboard, and then flicking a switch to sending the program or data to the computer. The whole idea behind this was to eliminate the errors arising from programming the computer by toggling an array of switches. The use of something like a natural language interface protects the computer from errors. A shell will validate input as it is made, and reject much nonsense. Jack Kerouac, the famous beatnik generation author, prepared one of his books on a teletype machine, substituting a world wide human audience for a boring old computer. He sent the publisher an enormous roll of paper. The book got printed. Jack Kerouac's novels contain florid language and much nonesense so like many sensational successes they become dated. The language of mathematical logic also appears nonsenseical to many people, but it is not so quickly outdated. Also mathematical logic tried to reduce fairly complex statements to short and terse expressions. Bertrand Russell spent much of his early life on this project until Kurt Godel went and constructed a meta-theory making much of Russell's mathematics redundant. Because hard copy terminals were the norm man machine intereaction was confined to extremely terse dialogue. This is well suited to meta-programming. Paradoxically one of the most verbose computer languages ever was also invented in this era. COBOL became the norm for business at the time. The reason for this is quite clear. Many businessmen really hated clever people unless they came from their own social class. Robert Oppenheimer, the acadamic responsible for leading the Manhatten project was classified as a security risk. Linus Pauling, the chemist whose work on protein chemistry paved the way for the discovery of the structure of DNA, was deprived of the right to travel from the USA. First and foremost the new technology was to be harnessed to meet the needs of American corporations. After the end of the 1941-45 war the brilliant minds were no longer needed. Alan Turing the pioneer of British computing was given a series of dead end jobs and victimised because of his sexual preferences. Cyberserfdom started right at the beginning. Loads of women were drafted into data preparation work with rooms full of people keying in punched cards to build corporate data bases. These people were always monitored for output with productivity measured in thousands of key presses per hour. Recent technological advances have merely been accompanied by the diagnosis and frequent employer denial of RSI or repetitive strain injury. Early computer pioneers really did not like this sort of strain so the intereactions designed by the scientists for their own use often tried to minimise repetitive typing. System software as opposed to business software made extensive use of 'macro processors' which would expand a few key-strokes into the generation of many commands or large data sets. This distinction lives on fifty years later. Programmers tend to prefer to use powerful tools such as 'vi' or 'emacs' for the preparation of text. Nowadays any decent text editor gives the writer access to all of the resources of the computer including the ability to pipeline the results of internet search-engine trawls into the document under preparation. Effectively this means that the editor has some sort of command window built in. Amongst the American corporations AT&T stands out. The farsighted executives of this company invested in an operating system to serve the needs of it's key workers at its research laboratories in New Jersey. They designed an operating system called UNIX which had a programmer friendly programming language called C and a user friendly operating system called UNIX. The commands were deliberately designed to avoid the hazards of RSI. Copy was abbreviated to cp and archive was abbreviated to 'ar' and so on. Unlike other organs of the human body the brain does not really wear out with increased use. This simple physiological fact is overlooked by many. Because Bell set up its research labs near Princeton University there was a good partnership between academia and business. IBM and Digital Equipment made similar efforts, but UNIX was really the most attractive system because the syntax of it's shell language went right back to the days of Babbage who was releasing papers on 'operator algebra' back in the 1830s. These ideas were later developed by Post, Church, Godel, Quine and Turing in the 1930s. By this time the operator and function algebras of Babbage's contemporaries had become known as 'Lambda Calculus'. Q: Why 'lambda calculus' ? A: Greek letter lambda. This was used to bind a function definition to its explanation. Twentieth century logicians invented partial functions. These are essentially rules for computing certain numbers where not all function values are defined. Summing infinite series could solve riddles like Zeno's paradox on the time taken for Achilles to outrun a tortoise, but the idea of partial functions where it's possible to start a well defined computation without knowing whether you will get a result is quite another type of problem. Probability theory is no help. Much theoretical work on early formal symbol manipulation systems went onto computers very early in their history to enable people to write language translators. Circular definitions became commonplace. Q: In the days of graphic user interface (GUI) the shell is obsolete. Why bother to learn anything about it ? A: You could also say that in the days of cheap calculators numeracy skills are no longer required. In these politically correct days no one is going to be allowed to fail a maths exam. China threw out the Red Guards in the late 1970s but in 'Merrie England' political correctness and political control of education surpasses the wildest dreams of megalomaniac Mao Dze Dong and his siren lover Qiang Qing. Old labour stalwarts were joined by Margaret Thatcher in a systematic attempt to destroy British Education. We see the results in innumerate accountants who sponsor idiotic business plans, engineers who design bridges without any knowledge of simple harmonic motion and computer companies whose executives have a worse understanding of time and date than the mediaeval popes who condemned Galileo and Bruno. As it happens most GUIs act as wrappers to shell scripts. The number of distinct job control languages has proliferated just as the number of layers of wrapping, but the underlying mechanism remains the same. Q: Traditional job control languages had cryptic commands with loads of peculiar signs like %, $, and loads of commas. No one is bothered with accuracy like that nowadays. The point and click interface is much less error prone isn't it ? A: Typing is a hassle. Who needs writing nowadays. Point and click is much faster. But it's still easy to make mistakes such as dragging the system folder to the trash bin, or selling shares for real rather than as part of a training excercise. The desktop is a filter and allows the user to see just what the software vendor wants the user to see. Big brother really loves you, so place trust in your software vendor. The vendor never loses money by underestimating the intelligence of the public. On Microsoft Windows the scripts which make up the Job Control Language are found in diverse places, and the description of how it all works is not really found in one place. The user interface is via form filling, rather than writing commas and names, but the results of the form filling go into special files and directories such as .pif files and the registry. Modern operating systems reflect the beaurocratic culture of the age in which it was born. The opening scene of the acclaimed movie, Schindler's list, shows officials typing up deportation dossiers. Intrusive governments and organised crime cartels also known as business enterprises made extensive use of computers to build knowledge bases which could keep their competitive advantage in excercising power. Concealment of knowledge is also important.

KNOWLEDGE BASES FOR THE ELITE, ARCADE GAMES FOR THE MASSES.

Next | Back|Top|End In order for people to break the hegemony of the USA and its criminal corporations it is necessary for the people to use the tools which endowed these organisations with power rather than simply buying up fertilizer and detonating truck bombs. Q: Learning programming is too hard nowadays. Why can't I just browse through hard core pornography at work ? A: Because too much of it will make you more likely to want to go and pay for a surgical procedure to increase the size of parts of your body. Unlike the sale of medications and drugs the medical establishment and governments excercise little control over new surgical procedures. There is generally no statutary process for the collection of statistics on such operations. Q: But if I still want to download hard core pornography can I be found out ? A: Almost surely. Most people who do this leave an electronic trace which is very easy to track. Someone just looks at a log of hits to a pornographic website, or newsgroup. If you use popular programs which have an embedded JCL then it is even quite easy for malicious hackers to fill up the web cache of your computer with illegal kiddie porn which could get you a jail sentence in many countries of the world. Furthermore if you are in a position of power you are quite likely to boast about your pornography collection when sexually harassing your employees. This type of behaviour ranges from the USA presidency and Supreme Court to the common 14K triad brothel owner. Q: Sounds dangerous. How can I clean up my computer? A: Write a script line such as: find / -type harcore-porn -exec 'xor-encrypt {} -key $FORGET;' Q: But Jack Straw says that I will go to jail if I forget my encryption key. How do I avoid this ? A: Delete the files. Modify the script. Q: But even if the files are deleted, people can find out what was on the hard disk. That's true isn't it ? A: Yes. There are programs which can read the hard disk several writes into the past. These programs are not necessarily easy to operate and their use involves removing the disk from the computer. If you get your computer confiscated for such forensic investigations you can forget that machine for about one year. Q: But with millions of people using the net it must be all but impossible for the authorities to keep up ? A: That's not entirely true. The internet has some rules which are rigidly enforced. These are adequate to make most of the system work for much of the time. These rules describe data transmission protocols and are the result of teamwork between government agencies, educational institutions and private business. Bill Gates has been percieved as a man who is not sufficiently part of the team to be allowed to succeed. There are fears that Microsoft could undermine standards by taking a short term profit driven point of view. The whole world was to be a mere extension of the MS WINDOWS series of operating systems. Janet Reno got involved in the witch hunt, or perhaps bounty hunt would be a more appropriate metaphor in the case of Bill Gates. The teamwork between Berkeley, the military and some of the computer companies was breaking down. Netscape and other corporations started crying foul. Issues of trade regulation were involved. Q: But the general public are showing their approval of Bill Gates by buying his systems ? A; Yes. Sometimes citizens revolt against their democratically elected governments. In this case most people are still running WINDOWS because Bill Gates is nothing like the Big Brother described in George Orwell's 1984. It couldn't possibly be true ! The great leaders of all of the capitalist corporations want exactly the same sway as the 'Big Brother' of Orwell's novel. They are all involved in setting up their own ministry of truth. Their ministry of love is extolled by the compassionate conservatism of George Bush, with incarcerations and executions, or perhaps the love of the great world leaders for the citizens of Iraq and Serbia struggling under the brutal dictatorships of Saddam & Slobodan. Bill Gates has nothing to do with this. Q: But what about the ministry of truth ? A: Orwell didn't realy forsee the SPAM, or self propogating advertising material. Philip Dick, the American science fiction writer had a good idea of what this was going to be like. He also knew that America was a police state just as much as Mao's China or Stalin's Russia. Just a trifle more effective. The Internet is a rumour mill become a vehicle of commerce. Q: What's this got to do with shell programming ? A: Twenty five years ago Bill Gates, then a law student, wrote a BASIC interpretor for MITS, a company in Texas. Microsoft was founded to supply a single customer who was selling micro computers for hobbyists. These early computers also used Digital Research's CP/M operating system but there were many computers that came with BASIC in the ROM. print 2+2 4 In the early days Microsoft got it right. Many new features got added to BASIC to such an extent that the inventors of the language slated Bill Gates and Microsoft in terms reminiscent of the Ayetollah's fatwa against Salman Rushdie. Bill Gates and his staff added features to BASIC so that it could be used to format floppy disks, paste colour images on screens and play music on the built in speaker circuitry. When the APPLE II became popular many people wanted more screen characters so an 80 column card was invented as a plug in. Many people also bought the Z80 CPU card so that they could run CP/M but Microsoft ensured that their own version of BASIC was installed. Microsoft also bought the rights for an operating system that had been developed to exploit Intel chips from a small West Coast firm whose name has been long forgotten. At that time Intel was publishing a lot of really technical documentation about IAPX development systems with hints of future possibilities such as protected memory and 32-bit addressing mode. Other computer companies such as IBM and Digital Equipment had long provided 32-bit systems and Motorala was already designing a 32-bit microprocessor but Microsoft needed to equal competition from other quarters. The Apple II had become popular because none of the 32-bit monsters could run a simple spread-sheet program called Visicalc. Many corporate computer users were reduced to borrowing time on their neighbours' Apple II in order to do their financial planning. Documents and mailing lists could be more easily set up on 8-bit computers running CP/M and Word Star rather than on corporate information systems, with perhaps the exception of UNIX users who could do anything they wanted with troff and TeX. Microsoft quickly produced their own spreadsheet and called it Multi-plan. They also helped develop MS-X which was a common operating system for a wide range of Japanese machines. MS-X offered a common file format for data on 8-bit machines and the IBM PC. It is known as FAT file system, because it uses a file allocation table to map out space on the disks. CP/M used a method whereby file allocation information is stored in directory entries. A long file needs several directory entries to accomodate the lists of allocation units. When IBM were planning the PC they approached both Microsoft and Digital Research. Urban legend has it that the owner of D.R. treated the IBM executives just like any other customers while Bill Gates got his employees to wear suits when they hosted the IBM team. It seems more likely that Digital Research was putting more priority on developing CP/M-68 to run on Motorala 68000 chips giving the users a real 32-bit OS. Who on earth could imagine that a brain dead architecture with segment registers and offsets could get anywhere ? Furthermore the early IBM PCs came with a video card that would give users a headache after just a short time of looking at a fuzzy screen. The fuzzy screen problem opened the way to many regional variations of the basic PC architecture. IBM came out with the enhanced graphics adapter, and then Chips & Technologies reduced a big card to just a single chip. Across the Pacific most Japanese companies started comissioning specialised chips to deal with the demands of their language. People who really wanted good quality font and image rendering used Apple machines or NeXT or went on to Silicon Graphics or SUN workstations. Q: Unix had a shell for decades, while MS-DOS and CP/M did not really offer so much. Why didn't UNIX catch on ? A: By the early 1980s several companies including ICL, Cromenco, and Microsoft were offering ports of UNIX to various 8-bit platforms. Because UNIX is big most systems offered only a subset of the UNIX facilities. File compression was still not so common and many of the small systems would skimp on such niceties as manual pages. A typical example is FORTUNE SYSTEMS who made a big thing about popularising UNIX in the mid 1980s. They were only interested in selling business systems so they tended to omit things like the C-compiler and many of the include files which contain a vast amount of detail on the historical development of UNIX and the Internet. Essentially FORTUNE came along with a proprietry word processor, a proprietry spreadsheet, and an amazingly complicated file system which always needed nursing back to life after any glitch in the power supply. To repair the file system the user was meant to type in disk block numbers by hand after making intricate calculations on the back of an envelope. During the 1970s several command language interfaces were common. Thoughtful IBM users would go for APL while MUMPS was a very servicable means of dragging health care data from a wide variety of computer systems. The Pick operating system was also available and this was designed for ease of use. Pick's system programming language was BASIC. Q: Is a shell the same as a system programming language ? A: Yes, it is, provided the user feels comfortable in using it. An employee is told to make a list of all the customers who did not order much in the last year and who owe money on their accounts. Often the quickest way to do this is to write a short script in SQL or DBASE-IV or whatever, then run the script and print the results. A GUI allows the user to fill in a form so that a script to extract the data will be created by an inference engine which may well be infernally clever in predicting what it thinks the user wants to do without actually saying anything. Netscape Communicator's handy method of assembling URLs from fragments of previous searches is a good example of such frustrating attempts by the computer to show intelligence. At this rate computers will be more intelligent than most of the human race in a decade or so. Human manned telephone call centers will become a thing of the past. Q: At least the GUI solves version incompatibility problems ? A: Sure. Windows offers only one sort of desktop. If you use LINUX then you will get a bewildering choice of different desktops. You can try and make your computer look like a SUN or Silicon Graphics workstation. You use 'X' rather than say Active-X. 'X' itself has been around for fifteen years or so. Do not confuse 'X' or active-X with X-rated websites. Q: My GUI offers a Wizard to sort out any problems. Is the wizard really that clever ? A: Norton Utilities and Winzip both employ wizards. Things must be looking up for Harry Potter's academy. In truth the wizard is just a page turner. The wizard will walk the user through a shell script, waving the magic wand at dragons and bad FATS and bit rotted partition tables. Anyone who has seen the UNIX file system check (fsck) at work will be happy to hold hands with a witch or a wizard. There's just no choice! Q: If the wizard is just a page turner, then why can't I read the book myself? A: Because most techie stuff makes designing an H-bomb look like a schoolkid's excercise. There is also the fact that software is written by different people to those who write the manuals. This means that many features described in manuals work rather differently in practice. The best thing to do is to get manuals which were written more than twenty years ago which describe systems which are still running today. Microsoft's first manuals on MS-DOS describe the MS-DOS prompt in Windows 95/98. In fact Microsoft have taken considerable trouble to iron out bugs in the earlier versions so that the DOS box is pretty much what they wanted it to be back in 1983. The best manuals to buy are the slimmed down copyright free no name books published in Taiwan or Singapore. If you like UNIX then the MKS system guide published in Canada ten years ago is good value. Five hundred and fifty pages of solid UNIX information for 50 cents is hard to beat. Microsoft's own early manuals were well written. Multi-Plan, and Lattice C both came with easy to read manuals. Their first DOS technical reference manual and the BIOS documentation for the IBM-PC were milestones in technical publishing. They also represent water that flowed under a bridge decades ago. This type of documentation is harder to find than the grimoires of medieval black magic reputedly locked up in the Vatican. Q: Why is good documentation hard to find these days? A: Because of the World Wide Web and the information explosion. Hypertext is an extension of the game of Dungeons and Dragons. Just as in those old style adventure games you need to remember to carry a roll of string so that you can find your way out of the maze. When HTML was first invented pressing the 'Go Back' button would get you out of the maze but that does not work with frames or active web content. Scientists recently discovered a slime mould which could navigate a maze by filling up the maze with protoplasm, then the bits of the mould which were in blind alleys would selectively die leaving a single filament spanning the maze from entrance to exit. This is a simple algorithm called depth first search described in any good book on combinatorics and graph theory. In the 1970s Isaac Asimov wrote an essay about the power of paper, and print. The conclusion was that books would never be obsolete because they don't need a power source, and they are therefore more portable than electronic media. Already just a couple of decades later books are getting a niche market. Furthermore anyone who regularly reads a newspaper such as The New York Times or even the French language 'Liberation' will see that these bloated journals are not particularly portable: they contain an incredible amount of junk information put out by commercial sponsors to such an extent that they deny their readers any rights to information. While all of this is going on in rich countries the right to read is being denied to many people in Sub-Saharan Africa. This a scandal of catastrophic proportians. Information Obesity can damage civilisations just as much as AIDS or malaria. Anthropologists argue that the development of language separated man from the apes and dolphins. Of course the loss of language could mean the extinction of humans. Lies and hypocracy become ever more seductive to the controlling elites and there are still substantial minorities that see this as a symptom of the Death of God. Q: Why are there so many different computer languages ? A: Evolution. In the 1950s the formal logic systems of Church, Post, Russell etc. were solutions waiting for problems. Hilbert's Tenth Problem had already been solved by such methods, but that did not really impress the people who make economic and political decisions.

PERL & SHELL BUILT IN VARIABLES

Next | Back|Top|End $* Same as $$[] $@ $$[I++] $# Size of $$ $? status of the most recently executed foreground pipeline. $- current option $$ process ID of the shell $! process ID of the most recently executed background command. $0 name of the shell or shell script. $_ last argument to the previous command. Sort of accumulator.

EXAMPLE ONE: A LOTTERY SCRIPT

Next | Back|Top|End #!/bin/bash # # Use of random number generator # Pick $2 numbers from 1 .. $1 # Default to UK National lottery selection # function shuffle() # randomly permute elements of a list { awk 'BEGIN {RS=" "; srand()} {printf "%8.6f%s\n", rand(),$0}'|\ sort -n |\ awk '{print substr($0, 9)}' } #defaults URL="http://d4maths.lowtech.org" n=6 m=49 if [ $# = 0 ]; then echo Lottery selection by $URL elif [ $# = 1 ]; then echo usage: $0 n m echo pick n numbers from m choices at random without replacement exit 0 else n=$1 m=$2 fi echo $n from $m if [ $n -gt $m ]; then echo domain error exit 0 fi a= i=0 while [ $i -lt $m ]; do i=$[ $i + 1 ] a="$a $i" done c=`echo $a | shuffle ` echo $c | awk -v n=$n 'BEGIN {RS=" ";ORS=" "} NR<=n {print}' echo " " exit 0

EXAMPLE TWO: DYNAMIC HTML PAGES

| Back|Top|End #!/bin/bash # server.sh display images from /home heirarchy # usage ./server.sh spec1 spec2 ... # where spec is a single quoted file type # example # # server.sh *.jpg *.gif # function shuffle() # randomly permute elements of a list { awk 'BEGIN {RS=" "; srand()} {printf "%8.6f%s\n", rand(), $0}' | \ sort -n | \ awk '{print substr($0, 9)}' } #defaults BROWSER=netscape delay=5 base=/home qshuffle=0 qgo=0 if [ $# = 0 ]; then echo usage: $0 {-go} {-shuffle} {-d delay} {-b base_directory} arg1 arg2 arg3 ... echo example: echo $0 -d 20 \'*.jpg\' \'*.gif\' exit 0 fi c=0 while [ $c = 0 ]; do case "$1" in -d) shift delay="$1" shift ;; -b) shift base="$1" shift ;; -go) shift qgo=1 ;; -shuffle) shift qshuffle=1 ;; *) c=1 esac done echo $delay echo $base # # concatenate lists # typical use of multiple quotes # a= for i; do b=`find "$base" -name "$i"` a="$a $b" done if [ $qshuffle = 1 ]; then echo wait. shuffling a c=`echo $a | shuffle` a=$c fi for IMG in $a; do k=`ls -l $IMG | awk '{print $5}'` echo Serving $IMG size $k if [ $k -le 10000 ]; then echo skipping $IMG continue fi # start browser if [ $qgo = 1 ]; then echo starting $BROWSER $BROWSER $PWD/dynamic.htm & qgo=0 fi # # This uses a here document. # Note that the value $IMG is substituted at run time. # cat << END_OF_HTML > dynamic.htm <HTML> <HEAD> <TITLE>Refresh</TITLE> <meta http-equiv="refresh" content="$delay; URL=dynamic.htm"> </HEAD> <BODY BGCOLOR="#FFFFFF"> <TABLE WIDTH=100% HEIGHT=100% BORDER=0 CELLPADDING=0 CELLSPACING=0> <TR ALIGN=CENTER VALIGN=MIDDLE> <TD>Image location<BR>$IMG<BR></TD> </TR> <TR> <TD><CENTER><IMG SRC="$IMG" BORDER=0></CENTER></TD> </TR> </TABLE> </BODY> </HTML> END_OF_HTML sleep ${delay}s done exit 0

Glossary

ADA	Countess of Lovelace. c1840.
Adabas	Database software developed c 1970.
ALGOL	Algorithmic Language. 1960.
APL	A Progamming Language. Array processing. Ken Iverson.
ASCII	Universal format for text files. Cheap & effective.
Assembler	Symbolic machine code. For nerds only...
AT&T	Bell Research labs in New Jersy is home of UNIX.
AVI	Video file format.
Babbage	Designer of analytic engine. c1840
BASIC	Beginners' All purpose Symbolic.
BCPL	Forerunner of C.
Bison	GNU version of Yacc.
Bool	Wrote 'Laws of Thought'. c1850
Bourne	Early UNIX pioneer. 'bash' is the Bourne shell.
Browser Wars	Internet Explorer verses Netscape.
buffer overflow	Loophole exploited by early hackers.
bus	hardware term.
bytesex	Big endian or little endian.
C	System programming language for UNIX. Pronounce See.
C++	Evolution of C
C#	Evolution of C++ and JAVA. Microsoft.
CGI	Common gateway interface. Server to HTML forms.
Chomsky N.	Language theoretician. Radical left politics.
client	Guest.
COBOL	Capitalist verbosity.
crack	Crack a password. A library.
D4	dialect of APL with ideas stolen from UNIX shell.
daemon	Background program. Often a server.
demon	Short for Demonstration. 'Demon with Sound'.
DEC	Digital Equipment Corporation. Also DEC
DES	Data encryption standard.
DJGPP	Excellent C Compiler for DOS/WINDOWS
e-mail	Electronic mail. Also E-commerce.
emacs	Editor based on Lisp. From M.I.T.
Euler	Solved 100 year old factorisation problem. 2^32+1.
expect	Simple event driven scripting language.
FascistCheck	Part of cracklib.
FAT	File allocation table.
FORTRAN	Formula Translator. 1950s language used today.
fry	to 'Sautee' a string is to permute its elements.
GIF	Graphic Image Format. Uses LZH
GNOME	Windows manager.
GNU	Genuinely not UNIX. Public domain software project.
Godel	Designed a code to express all logic statements.
GUI	Graphic user interface. Eats up resources. Expensive.
Heisenbug	Bug that dissapears when debugging is turned on.
Hilbert	Set the problem solved by Turing. c1905.
HTML	Hypertext Markup Language.
HSV	Hue Saturation Value colour encoding.
Hacker	Sort of programmer. Often anti-capitalist.
Huffman codes	Stochastic data compression technique. c1950
Illegal Instruction	Program obeys data. Equal scores in browser wars.
Installer	Program to put other programs on the computer.
J	Evolution of APL. Iverson.
Java	C++ like programming language for active content.
JPEG	Joint Picture Group. Image compression.
K	Database language.
K&R	Kernigan and Ritchie. Writers of first book on C.
KDE	Popular Linux desktop.
Knuth, D.E.	Creator of opus: Art of Computer Programming.
Lab	Colour co-ordinate system.
LINUX	Clone of UNIX implemented by Linus Torvalds.
LZH	Lev-Zimple Huffman compression technique.
M.I.T.	Massachusts institute of technology.
macro	Canned text, often used to save typing.
magic	Signature used to identify file type
Magick	Esoteric arts. see witchcraft
Maple	A popular maths programming language.
MPEG	Video encoding. Motion Picture Group.
MUD	Multi User Dungeon.
NeXT	Black box computer. Evolution of Apple Mac.
OLE	Object Linked Environment.
Open System	System where full explanations are given to user.
P=NP	Conjecture about algorithms.
PDF	'Portable document format'. Needs Adobe Acrobat.
perl	Pathologically eclectic rubbish lister. Larry Wall.
PINE	Easy to use mailing program. Public domain.
pod	Plain ordinary documentation.
PostScript	Image processing language. Used in printers.
python	Scripting language. CWI.
Reverse engineering	Unfortunate necessity in capitalist system.
Ramanujan	Invented modern methods for computing 'Pi'.
RGB	Red Green Blue. Colour co-ordinates.
RTF	Rich text format. For those with resources to waste.
Russel B	Logician -> radical left politics.
salt	Sprinkle this on your DES.
sanity check	Can be put in programs. Needs thought.
Segment Violation	Attempt to access data out of range
semaphore	Queue discipline method. Dijkstra.
setuid	Upwards mobility in UNIX permissions heirarchy
signal	Form of interprocess communication.
Shell	Command interface. Cheaper to implement than GUI.
Sloane N.J.A.	AT&T researcher. Integer sequence database.
strip	Strip symbols from binaries.
tar	File archive format. 'Let them eat tar'.
Tcl	Scripting language for X. Berkeley.
TeX	Pronounce as Tecch. WISAWYG document praparation
TIFF	Tagged Image Format
TIN	Easy to use news reading program.
Turing	Computer scientist in early twentieth century.
UNIX	Computer operating system invented by AT&T
vi	Visual intereactive editor.
virus	Sometimes malignant program or script.
Von Neumann	Inventor of logical model for modern computers.
VB	Visual Basic. Embedded in Microsoft Office.
VRML	Virtual Reality modelling language.
VT100	DEC terminal. Immortalised by emulation programs.
Winzip	Popular Windows archiver. Blocking Copyright message.
witchcraft	Term used to describe what people don't understand.
WISAWYG	What I see ain't what you get.
wizard	Directed help text for programs.
worm	Sometimes malignant installer.
WYSIWYG	What you see is what you get.
X	Unix windows server.
XYZ	Transformed colour encoding.
yacc	Yet another compiler compiler
zip	Data compression/decompression techniques.
zombie	An undead process. To kill it, close the pipe.

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