The Quine Page(self-reproducing code)
The Quine Page (self-reproducing code)





    One day, several years ago, I came across an
article in an old Byte on "self-reproducing
programs".  I was a curious lad, and looked to see what the article
was about.  It said, "Listing 1 is a C program which duplicates itself. 
When the program is run it produces (on the standard output) a file containing
an exact copy of its own source code".  I was hooked immediately--these
guys must be
geniuses!  I copied the article at once, and tried
to figure it out, but I didn't know C at the time.  Soon after, I
found another article, this one in Creative
Computing.  It had listings in BASIC, and I was ecstatic. 
I soon realized that anyone could write self-reproducing programs, and
made a few in BASIC, Pascal, and Forth.
    Later that year I finally got a PC, and quickly
forgot about the programs I had written on my old TI-994/A.  Then,
last year, as I was skimming through the Jargon file, I saw an entry I
had not noticed before:
:quine: /kwi:n/ /n./ [from the name of the logician
Willard van Orman Quine, via Douglas Hofstadter] A program that generates
a copy of its own source text as its complete output. Devising the shortest
possible quine in some given programming language is a common hackish amusement.
Here is one classic quine:
     ((lambda (x)
       (list x (list (quote quote) x)))
      (quote
         (lambda (x)
           (list x (list (quote quote) x)))))
This one works in LISP or Scheme. It's relatively easy to write quines
in other languages such as Postscript which readily handle programs as
data; much harder (and thus more challenging!) in languages like C which
do not. Here is a classic C quine for ASCII machines:
     char*f="char*f=%c%s%c;main()
     {printf(f,34,f,34,10);}%c";
     main(){printf(f,34,f,34,10);}
For excruciatingly exact quinishness, remove the interior line breaks.
Some infamous
Obfuscated C Contest
entries have been quines that reproduced in exotic ways.
    "Wow.  A 'common hackish amusement'.  I've
seen the Beer List, and the Hello World page, there must be a Quine Page. 
I'll have to look around, that should be pretty neat to see what must be
hundreds of quines."
    I was half right.  There were hundreds of quines,
just no quine page.  Admittedly, there were a few attempts, but none
had more than ten or so.  I had found over fifty by the time I came
across any of these pages.
    Here is (hopefully) the definitive page.  You
can check out the plain quine section, the self-reproduction
variations section, and bibliography. 
If you've visited before, browse the what's new
section. Take a look at the want list of languages
I'm specifically looking for. Finally, you can browse a list of links.


What's New
6/21/99   New Languages: ABC, J, Haskell, Oberon.  I've created
an other section for stuff that doesn't fit anywhere
              
else.  This page now mirrored on grex.cyberspace.org
--support Not-for-profit net access & free shells.  Also got rid of those nasty gifs
and replaced them with nice PNG's 
3/28/99   New Languages: False, Javascript.  Lots of
pascal entries for some reason...I'm now listed
              
on Yahoo!
3/1/99     New Languages: RPL, ML, snack, inform. 
A couple of new palindromes in C, and as
                
usual, several miscellaneous entries.  Linked to my (very small) polyglot
page.
2/20/99   New Languages: APL, CAML, dBASE, lua, prolog, Smalltalk. 
A bunch of new iterating
               
quines.  Sorry it's taken so long to put up all the new code everyone
has given me.
12/27/98 New languages: Forth, Rexx, Scheme, Logo, Modula-2, TSE. 
New variation:
               
object-printing programs.  Linked to IOCCC and GEB FAQ.  A ton
of new code.
12/23/98 Added another Intercal program, and did some minor fixes.
12/22/98 Everything
 

Plain (single language) Quines
    I define a quine as a program which reproduces itself
on an output device without inputting its source.  For programs of
that nature, see the cheats section.
    Included in these pages are some minor variations
(.sigs, backwards printing programs, palindromes) which may at some point
be given their own categories.
 ABC
 Ada
 Algol
 APL
 Assembly
 Awk
 BASIC
 BeFunge
 BlooP
 BrainF***
 C
 C++
 Objective CAML
 dBASE
 Emacs Lisp
 False
 Forth
 Fortran
 Haskell
 HP 48 RPL
 Icon
 Inform
 Intercal
 Interpol
 J
 Java
 More Java
 Javascript
 LISP
 Logo
 Lpc
 Lua
 Miranda
 ML
 Modula-2
 MUMPS
 Oberon
 Pascal
 Perl
 More Perl
 Postscript
 POV-Ray
 Prolog
 Python
 Rexx
 Scheme
 SGML
 Smalltalk
 Snack
 SNOBOL 4
 Tcl
 TeX
 TSE
 Unix Shell
 Vi

Variations

 Multiple Languages(polyglots)
 Iterating Quines
 Quine Generating Programs
 Kimian Self Reproduction
 Object Printing Programs
 Other
Cheats (right now these are in the language entries.  They'll soon
have their own category)

Bibliography
 

Want List
Anything you have...
    I am especially looking for the major classic (or
infamous) languages: COBOL (I'll freely withhold the name of the programmer
if they wish ;) ), Jovial, PL/I, SIMULA, Teco, etc.
    I should probably point you to my submissions
page.  Also, if you wrote one of these programs and are angry that
I 'stole' it see my copyright page.
 


Links
The Free Compilers list
indexes compilers, interpreters, and language-related tools available
free and in source on the Internet. You can download
or search it from here.
The Language List
is a historically-oriented list of over 2300 languages which also includes
pointers to sources. You can download
or
search it from here.
You can also use anonymous FTP from rtfm.mit.edu in the `/usenet/comp.lang.misc'
directory to obtain either of these lists.
The Jargon File
A collection of Internet slang, folklore, and history. One of the most
fascinating documents I have ever seen.  Read it.  Buy the book
too.
The Beer
List
List of implementations of a program to print out the entire lyrics
of "99 Bottles Of Beer On The Wall" in different programming languages. 
I think of it and the Hello World page as a wish list.  Someday this
collection will be that big!
The "Hello, World"
Page
Like the above, but for "Hello, World".  Better organized too.
The Retrocomputing Museum
A great resource of old, legendary computing programs compiled by the
editor of the Jargon File.  Everything from APL written by Ken Thompson
to Wumpus.  I also stole part of his links section ;)
 The IOCCC Headquarters
Short for "International Obfuscated C Code Contest"  this is a
wonderful rescource of really, really ugly code.  Several entries
have been quines or variations thereof.
 alt.fan.hofstadter
and GEB FAQ
Lots of neat stuff here.  Self-reference galore.
 The Search
for Self-Documenting Code
A paper on how to write quines.  Well written.  I have another
written by Terry Reedy I
need to put up sometime.
The Polyglot
List
Compiled by yours truly, the several multiple language programs I have.
Yahoo!
list of quine pages
Pretty self-explanitory




Gary
P. Thompson II  <gthompso@nyx.net> 


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