556 lines
24 KiB
Plaintext
556 lines
24 KiB
Plaintext
18th International Obfuscated C Code Contest Guidelines, Hints and Comments
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Copyright (C) 2005 Leonid A. Broukhis, Simon Cooper, Landon Curt Noll and
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Peter Seebach.
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All Rights Reserved. Permission for personal, education or non-profit use is
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granted provided this this copyright and notice are included in its entirety
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and remains unaltered. All other uses must receive prior permission in
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writing from the contest judges.
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ABOUT THIS FILE:
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This file contains guidelines intended to help people who wish to
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submit entries to the International Obfuscated C Code Contest (IOCCC
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for short).
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This is not the IOCCC rules, though it does contain comments about
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them. The guidelines should be viewed as hints and suggestions.
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Entries that violate the guidelines but remain within the rules are
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allowed. Even so, you are safer if you remain within the guidelines.
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You should read the current IOCCC rules, prior to submitting entries.
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The rules are typically sent out with these guidelines.
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| WHAT'S NEW IN 2005:
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| The contest runs from 21-Mar-2005 00:00 UTC to 22-May-2005 23:59:59 UTC.
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| We will only accept online submissions this year.
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See the following for details,
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| https://www.ioccc.org/2005/submit
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| Most of the changes in the rules and guidelines for this year have been
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| marked with a "|" character on the left hand side.
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HINTS AND SUGGESTIONS:
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You are encouraged to examine the winners of previous contests. See
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FOR MORE INFORMATION for details on how to get previous winners.
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Keep in mind that rules change from year to year, so some winning entries
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may not be valid entries this year. What was unique and novel one year
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might be 'old' the next year.
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An entry is usually examined in a number of ways. We typically apply
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a number of tests to an entry:
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* look at the original source
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* convert ANSI trigraphs to ASCII
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* C pre-process the source ignoring '#include' lines
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* C pre-process the source ignoring '#define' and '#include' lines
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* run it through a C beautifier
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* examine the algorithm
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* compile it (with flags to enable all warnings)
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* execute it
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You should consider how your entry looks in each of the above tests.
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You should ask yourself if your entry remains obscure after it has been
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'cleaned up' by the C pre-processor and a C beautifier.
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Your entry need not pass all of the above tests. In certain
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cases, a test is not important. Entries that compete for the
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'strangest/most creative source layout' need not do as well as
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others in terms of their algorithm. On the other hand, given
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two such entries, we are more inclined to pick the entry that
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does something interesting when you run it.
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We try to avoid limiting creativity in our rules. As such, we leave
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the contest open for creative rule interpretation. As in real life
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programming, interpreting a requirements document or a customer request
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is important. For this reason, we often award 'worst abuse of the
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rules' to an entry that illustrates this point in an ironic way.
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We do realize that there are holes in the rules, and invite entries
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to attempt to exploit them. We will award 'worst abuse of the rules'
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and then plug the hole next year. Even so, we will attempt to use
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the smallest plug needed, if not smaller. :-)
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Check out your program and be sure that it works. We sometimes make
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the effort to debug an entry that has a slight problem, particularly
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in or near the final round. On the other hand, we have seen some
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of the best entries fall down because they didn't work.
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We tend to look down on a prime number printer, that claims that
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16 is a prime number. If you do have a bug, you are better off
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documenting it. Noting "this entry sometimes prints the 4th power
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of a prime by mistake" would save the above entry. And sometimes,
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a strange bug/feature can even help the entry! Of course, a correctly
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working entry is best.
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People who are considering to just use some complex mathematical
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function or state machine to spell out something such as "hello,
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world!" may want to try and be more creative.
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Ultra-obfuscated programs are in some cases some cases easier to
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deobfuscate than subtly-obfuscated programs. Consider using
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misleading or subtle tricks layered on top of or under an
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appropriate level of obfuscation.
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Programs that use VTxxx/ANSI sequences that are NOT limited to a
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specific terminal brand and that can also work in a standard xterm
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are considered portable.
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OUR LIKES AND DISLIKES:
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Doing masses of #defines to obscure the source has become 'old'. We
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tend to 'see thru' masses of #defines due to our pre-processor tests
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that we apply. Simply abusing #defines or -Dfoo=bar won't go as far
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as a program that is more well rounded in confusion.
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Many ANSI C compilers dislike the following code, and so do we:
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#define d define
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#d foo <-- don't expect this to turn into #define foo
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When declaring local or global variables, you should declare the type:
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int this_is_ok;
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this_is_not; <-- don't use such implicit type declarations
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We suggest that you compile your entry with an ANSI C compiler. If you
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must use non-ANSI C, such as K&R C, you must avoid areas that result in
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compile/link errors for ANSI C compilers. For example, using gcc
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local function declarations, such as:
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int
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main() {
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void blah() { printf("blah\n"); }
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blah();
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}
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are not allowed even though their existence seems tailor made for
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this contest! But for now, since they are not in wide spread use
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we cannot accept entries that use them.
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If your entry uses functions that have a variable number of
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arguments, be careful. Systems implement va_list as a wide variety
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of ways. Because of this, a number of operations using va_list are
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not portable and must not be used:
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* assigning a non-va_list variable to/from a va_list variable
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* casting a non-va_list variable into/from a va_list variable
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* passing a va_list variable to a function expecting a non-va_list arg
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* passing a non-va_list variable to a function expecting a va_list arg
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* performing arithmetic on va_list variables
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* using va_list as a structure or union
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In particular, do not treat va_list variables as if they were a char **'s.
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Avoid using <varargs.h>. Use <stdarg.h> instead.
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If you use C preprocessor directives (#define, #if, #ifdef, ...),
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the leading '#' must be the first non-whitespace character on a line.
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While some broken C preprocessors do not allow whitespace before a
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'#', most do.
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The exit() function returns void. On some broken systems have exit()
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return int. Your entry should assume that exit() returns a void.
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Small programs are best when they are short, obscure and concise.
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While such programs are not as complex as other winners, they do
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serve a useful purpose. They are often the only program that people
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attempt to completely understand. For this reason, we look for
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programs that are compact, and are instructional.
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One line programs should be short one line programs, say around 80
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bytes long. Getting close to 160 bytes is a bit too long in our opinion.
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We tend to dislike programs that:
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* are very hardware specific
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* are very OS version specific
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(index/strchr differences are ok, but socket/streams specific
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code is likely not to be)
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* dump core or have compiler warnings
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(it is ok only if you warn us in the 'remark' header item)
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* won't compile or run under a POSIX P1003.1/P1003.2 like systems
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* depend on a utility or application not normally found on most
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most POSIX P1003.1/P1003.2 like systems
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* abuse the build file to get around the size limit
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* obfuscate by excessive use of ANSI trigraphs
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* are longer than they need to be
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* are similar to previous winners
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* are identical to previous losers :-)
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Unless you are cramped for space, or unless you are entering the
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'best one liner' category, we suggest that you format your program
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in a more creative way than simply forming excessively long lines.
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The build file should not be used to try and get around the size
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limit. It is one thing to make use of a several -D's to help out,
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but it is quite another to use 200+ bytes of -D's in order to
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try and squeeze the source under the size limit. You should feel
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free to make use of the build file space, but you are better off
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if you show some amount of restraint.
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You should try to restrict commands used on the build file to
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POSIX-like or common Unix-like commands. You can also compile
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and use your own programs. If you do, try to build and execute
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from the current directory. This restriction is not a hard and
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absolute one. The intent is to ensure that the building if your
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program is reasonably portable.
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Don't forget that the building of your program should be done
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***without human intervention***. So don't do:
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cat > prog.c
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cc prog.c -o prog
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However, you can do something cute such as making your program
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do something dumb (or cute) when build 'automatically'. However
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when it is run with a human involved, do something more clever.
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For example, one could use the build instructions:
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cc prog.c -DNONHUMAN -o prog
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echo "See remarks section about alternate ways to compile"
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and then include special notes in the program "remarks" for
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alternate / human intervention based building.
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We want to get away from source that is simply a compact blob of
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characters. To help, we give a break to source that contains
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whitespace, and in certain cases ; { or } characters. While the
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number of characters excluding whitespace (tab, space, newline),
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and excluding any ; { or } followed immediately by either whitespace
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or end of file, must be <= 2048, the total size may be less than 4096
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bytes. This means that one may use "free of charge" up to 2048
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bytes of whitespace, or ; { or } followed by either whitespace
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or end of file.
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Please do not use things like gzip to get around the size limit.
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Given two versions of the same program, one that is a compact blob
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of code, and the other that is formatted more like a typical C
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program, we tend to favor the second version. Of course, a third
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version of the same program that is formatted in an interesting
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and/or obfuscated way, would definitely win over the first two!
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We suggest that you avoid trying for the 'smallest self-replicating'
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source. The smallest, a zero byte entry, won in 1994.
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We do not like writable strings. That is, we don't want stuff like:
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char *T = "So many primes, so little time!";
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...
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T[14] = ';';
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Please don't make use of this feature, even if your system allows it.
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However, initialized char arrays are OK to write over. This is OK:
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char b[] = "Is this Ok";
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b[9] = 'K';
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X client entries should be as portable as possible. Entries that
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adapt to a wide collection of environments will be favored. Don't
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depend on a particular type of display. For example, don't depend
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on color or a given size. Don't require backing store.
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X client entries should avoid using X related libraries and
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software that is not in wide spread use.
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We don't like entries that use proprietary M*tif, Xv*ew, or OpenL*ok
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toolkits, since not everyone has them. Use of OpenMotif is permitted
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because it is more widely and freely available.
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You should avoid depending on a particular window manager.
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X client entries should not to depend on particular items on
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.Xdefaults. If you must do so, be sure to note the required lines
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in the program "remarks".
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While we recognize that UNIX is not a universal operating system, the
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contest does have a bias towards such systems. In an effort to expand
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the scope of the contest, we phrase our bias in terms of POSIX P1003.1
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and P1003.2 standards. This will allow certain non-UNIX OS users to
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submit entries. On the other hand, this is a guideline and not a rule.
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We will not reject an entry based on some POSIX technicality.
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When dealing with OS and application environments, we suggest that you
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be reasonable with a nod towards vanilla UNIX-like systems. POSIX will
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evolve but not as much as the contest, so avoid stuff like POSIX real
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time, security, etc.
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We like programs that:
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* are as concise and small as they need to be
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* do something at least quasi-interesting
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* are portable
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* are unique or novel in their obfuscation style
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* MAKE USE OF A NUMBER OF DIFFERENT TYPES OF OBFUSCATION <== HINT!!
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* make us laugh and/or throw up :-) (humor helps!)
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Some types of programs can't excel (tm) in some areas. Of course, your
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program doesn't have to excel in all areas, but doing well in several
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areas really does help.
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You are better off explaining what your entry does in the program
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"remarks" section rather than leaving it obscure for the judges
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as we might miss something and/or be too tired to notice.
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We freely admit that interesting, creative or humorous comments in
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the program "remarks" help your chances of winning. If you had to
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read so many twisted entries, you too would enjoy a good laugh or two.
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We think the readers of the contest winners do as well. We do read
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the program "remarks" during the judging process, so it is worth your
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while to write remarkable program "remarks".
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We dislike C code with trailing control-M's (\r or \015) that results
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in compilation failures. Some non-Unix/non-Linux tools such as
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MS Visual C and MS Visual C++ leave trailing control-M's on lines.
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Users of such tools should strip off such control-M's before submitting
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their entries. In some cases tools have a "Save As" option that will
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prevent such trailing control-M's being added.
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We dislike entries that depend on non-portable libcurses features such
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as halfdelay(). One should restrict libcurses to portable features
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found on BSD and SVR4/System V curses.
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The rules disallow source that contains unescaped octets with values
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between 128 and 255. You must use \octal or \hex escapes instead:
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/* 123456789 123456789 123456789 123456 */
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char *foo = "This string is 36 octets in length \263";
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/* This octet requires 4 octets of source ^^^^ */
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if (strlen(foo) == 36) printf("foo is 36 octets a final NUL\n");
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Be creative!
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ABUSING THE RULES:
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Legal abuse of the rules is somewhat encouraged. Legal rule abuse may
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involve, but is not limited to, doing things that are technically
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allowed by the rules and yet do not fit the spirit of what we intended
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to be submitted.
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Legal rule abuse is encouraged to help promote creativity. Rule abuse
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entries, regardless of if they receive an award, result in changes to
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the next year's rules and guidelines.
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Legal abuse of the rules is NOT an invitation to violate the rules.
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An entry that violates the rules in the opinion of the judges, WILL be
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disqualified. RULE ABUSE CARRIES A CERTAIN LEVEL OF RISK! If you
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have an entry that might otherwise be interesting, you might want to
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submit two versions; one that does not abuse the rules and one that
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does.
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If you intend to abuse the rules, indicate so in the program
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"remarks". You must try to justify why you consider your rule abuse
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to be allowed under the rules. That is, you must plead your case as
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to why your entry is valid. Humor and/or creativity help plead a
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case.
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| Abusing the web submission procedure tends to annoy us more
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| than amuse us. Spend your creative energy on content of your
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| entry rather than on the submission process itself.
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We are often asked why the contest rules and guidelines seem too
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strange or contain mistakes, flaws or grammatical errors. One reason
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is that we sometimes make genuine mistakes. But in many cases such
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problems, flaws or areas of confusion are deliberate. Changes to
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rules and guidelines in response to rule abuses, are done in a minimal
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fashion. Often we will deliberately leave behind holes (or introduce
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new ones) so that future rule abuse may continue.
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At the risk of stating the obvious, this contest is a parody of the
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software development process. The rules and guidelines are only a
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small part of the overall contest. Even so, one may think the contest
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rules and guideline process as a parody of the sometimes tragic
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mismatch between what a customer (or marketing) wants and what
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engineering delivers.
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JUDGING PROCESS:
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Entries are judged by Leonid A. Broukhis, Simon Cooper, Landon Curt Noll
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and Peter Seebach.
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Each entry submitted is given an id number and subdirectory. The
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"program", "info", "build" and "remarks" portions of a submission are
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stored and judged from this directory.
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Any "author" and identifiable "entry" information is not read until
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the judging process is complete, and then only from entries that have
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won an award.
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The above process helps keep us biased for/against any one particular
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| individual. Therefore you MUST refrain from putting any information
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| that reveals your identity in the "program", "info", "build", or "remarks"
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| portions of your entry. We are usually kept in the dark as much as you
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| are until the final awards are given. We like the surprise of finding
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out in the end, who won and where they were from.
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We attempt to keep all entries anonymous, unless they win an award.
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Because the main 'prize' of winning is being announced, we make all
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attempts to send non-winners into oblivion. We remove all non-winning
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files, and shred all related paper. By tradition, we do not even
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reveal the number of entries that we received. (For the curious,
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we do indicate the volume of paper consumed when presenting the IOCCC
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winners at talks)
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After the initial announcement, we attempt to send an email to the
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authors of the winning entries. One reason we do this is to give
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the authors a chance to comment on the way we have presented their
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entry. They are given the chance to correct mistakes and typos. We
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often accept their suggestions/comments about our remarks as well.
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This is done prior to posting the winners to the wide world.
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Judging consists of a number of elimination rounds. During a round,
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the collection of entries are divided into two roughly equal piles;
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the pile that advances on to the next round, and the pile that does
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not. We also re-examine the entries that were eliminated in the
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previous round. Thus, an entry gets at least two readings.
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A reading consists of a number of actions:
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* reading the "build" information
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* reading the "program"
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* reading the program "info", if any
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* passing the source thru the C pre-processor
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skipping over any #include files
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* performing a number of C beautify/cleanup edits on the source
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* passing the beautified source thru the C pre-processor
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skipping over any #include files
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In later rounds, other actions are performed:
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* compiling/building the source
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* running the program
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* performing miscellaneous tests on the source and binary
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Until we reduce the stack of entries down to about 25 entries, entries
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are judged on an individual basis. An entry is set aside because it
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does not, in our opinion, meet the standard established by the round.
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When the number of entries thins to about 25 entries, we begin to form
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award categories. Entries begin to compete with each other for awards.
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An entry will often compete in several categories.
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The actual award category list will vary depending on the types of entries
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we receive. A typical category list might be:
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* best small one line program
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* best small program
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* strangest/most creative source layout
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* most useful obfuscated program
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* best game that is obfuscated
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* most creatively obfuscated program
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* most deceptive C code
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* best X client (see OUR LIKES AND DISLIKES)
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* best abuse of ANSI C
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* worst abuse of the rules
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* (anything else so strange that it deserves an award)
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We do not limit ourselves to this list. For example, a few entries are so
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good/bad that they are declared winners at the start of the final round.
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We will invent awards categories for them, if necessary.
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In the final round process, we perform the difficult tasks of
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reducing the remaining entries (typically about 25) down to 8 or 10
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winners. Often we are confident that the entries that make it into
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the final round are definitely better than the ones that do not
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make it. The selection of the winners out of the final round, is
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less clear cut.
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Sometimes a final round entry is good enough to win, but is beat out
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by a similar, but slightly better entry. For this reason, it is
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sometimes worthwhile to re-enter an improved version of an entry
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that failed to win in a previous year. This assumes, of course,
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that the entry is worth improving in the first place!
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More often than not, we select a small entry (usually one line), a
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strange/creative layout entry, and an entry that abuses the contest
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rules in some way.
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In the end, we traditionally pick one entry as 'best'. Sometimes such
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an entry simply far exceeds any of the other entries. More often, the
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'best' is picked because it does well in a number of categories.
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ANNOUNCEMENT OF WINNERS:
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The judges will post an initial announcement of who won, the name
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of their award, and a very brief description of the winning entry
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on the IOCCC website:
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https://www.ioccc.org/whowon.html
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We will also submit a brief announcement story to /.:
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https://slashdot.org
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that, depending on the willingness of the /. editors, may be posted
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to their site at the same time.
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Note that initial announcement will NOT contain source. This is because
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the winning authors are given a chance to review the judges comments,
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and test our Makefile. This review process typically takes a few weeks.
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Sometime after the initial announcement, and once the review
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by the winners has been completed, the winning source will be
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posted to the IOCCC website:
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https://www.ioccc.org/years.html
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NOTE: previous winners are available at that URL
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We will submit a story announcing the availability of the winners
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to /. at the same time.
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Finally the winning entries will be posted to the following groups:
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comp.lang.c comp.lang.c.moderated alt.sources
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In addition, pointers to these postings are posted to the following
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comp.sources.misc comp.windows.x comp.programming
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misc.misc comp.std.c alt.folklore.computers
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Often, winning entries are published in selected magazines from around
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the world. Winners have appeared in books ("The New Hackers Dictionary")
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and on T-Shirts.
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Last, but not least, winners receive international fame and flames! :-)
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FOR MORE INFORMATION:
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You may contact the judges by sending an email to the following address:
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| q.2005@ioccc.org (do not submit entries to this address)
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| You must include the words 'ioccc 2005 question' in the subject of your
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email when sending email to the judges.
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Questions and comments about the contest are welcome. Comments about
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confusing rules and guidelines are also welcome.
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The rules and the guidelines may (and often do) change from year to
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year. You should be sure you have the current rules and guidelines
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prior to submitting entries.
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Check out the IOCCC Web page:
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https://www.ioccc.org
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It has rules, guidelines and winners of previous contests (1984 to date).
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Leonid A. Broukhis
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Simon Cooper
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chongo (Landon Curt Noll) /\cc/\
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Peter Seebach
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