50 KiB
FAQ Table of Contents
Section 0 - History of the IOCCC
- 0.0 - How did the IOCCC get started?
- 0.1 - Why are some years missing IOCCC winners?
- 0.2 - Why do some IOCCC winners receive the Grand Prize or Best of Show award?
Section 1 - Submitting entries to a new IOCCC
- 1.0 - What types of entries have been over-submitted to the IOCCC?
- 1.1 - What should I put in my entry's Makefile?
- 1.2 - May I use a different source or compiled filename than prog.c or prog?
- 1.3 - What platform should I assume for my entry?
Section 2 - IOCCC Judging process
- 2.0 - How many entries do the judges receive for a given IOCCC?
- 2.1 - What should I put in the remarks.md file of my entry?
- 2.2 - Why don't you publish non-winners?
- 2.3 - How much time does it take to judge the contest?
- 2.4 - How many judging rounds do you have?
Section 3 - Compiling and running IOCCC winners
- 3.0 - What Makefile are available to build or clean up IOCCC winners?
- 3.1 - Why doesn't this IOCCC winner compile?
- 3.2 - Why does a IOCCC winner fail on my 64-bit system?
- 3.3 - Why do some IOCCC winners fail to compile under macOS?
- 3.4 - Why does clang or gcc fail to compile an IOCCC winner?
- 3.5 - What is this cb tool that is mentioned in the IOCCC?
- 3.6 - An IOCCC winner missed by my terminal application, how do I fix this?
- 3.7 - How do I compile and use on macOS, an IOCCC winner that requires X11?
- 3.8 - How do I compile an IOCCC winner that requires SDL1 or SDL2?
- 3.9 - How do I compile an IOCCC winner that requires (n)curses?
- 3.10 - How do I compile and use on macOS, an IOCCC winner that requires sound?
- 3.11 - Why do Makefiles use -Weverything with clang?
Section 4 - Changes made to IOCCC winners
- 4.0 - Why are some winning author remarks incongruent with the winning IOCCC code?
- 4.1 - Why were some calls to the libc function gets changed to use fgets?
- 4.2 - What was changed in an IOCCC winner source code?
- 4.3 - Why do author remarks sometimes not match the source?
- 4.4 - What is the meaning of the file ending in .orig.c in IOCCC winners?
Section 5 - Updating or correcting IOCCC web site content
- 5.0 - Why does an IOCCC winner fail to compile or or fail run?
- 5.1 - How do I report a bug in an IOCCC winner?
Section 6 - Miscellaneous IOCCC
- 6.0 - How did an entry breaks the size rule 2, win the IOCCC?
- 6.1 - Is there a list of known bugs and (mis)features of IOCCC winners?
- 6.2 - May I mirror the IOCCC web site?
- 6.3 - May I use parts of the IOCCC in an article, book, newsletter, or instructional material?
- 6.4 - Why do you sometimes use the first person plural?
The IOCCC FAQ
Section 0: History of the IOCCC
FAQ 0.0: How did the IOCCC get started?
One day (1984 March 23 to be exact), Larry Bassel and I (Landon Curt Noll) were working for National Semiconductor's Genix porting group, we were both in our offices trying to fix some very broken code.
Larry had been trying to fix a bug in the classic Bourne shell (C code #defined to death to sort of look like Algol) and I had been working on the finger program from early BSD (a bug ridden finger implementation to be sure).
We happened to both wander (at the same time) out to the hallway in Building 7C to clear our heads.
We began to compare notes: 'You won't believe the code I am trying to fix'.
And: 'Well you cannot imagine the brain damage level of the code I'm trying to fix'.
As well as: 'It's more than bad code, the author really had to try to make it this bad!
After a few minutes we wandered back into my office where I posted a flame to net.lang.c inviting people to try and out obfuscate the UN*X source code we had just been working on.
BTW: I (Landon Curt Noll) had to post this typo correction. Thus began the tradition of putting typos in the contest rules and guidelines ... to make them more obfuscated of course! :-)
BTW: This posting was made back in the days when AT&T was the evil giant. Now, Microsoft makes AT&T look mild and kind in comparison. :-( (IMHO) ).
BTW: See the story about the 'Bill Gates' award. :-)
OK, back to the story.
We (Larry and I) received a number of entries by email. When we began to receive messages from outside of the US, Larry and I decided to include International in the name.
The 1st IOCCC winners were posted on 17 April 1984.
There were 4 winners in 1984:
BTW: The (dis)honorable mention wished to remain anonymous. While many have asked who it was, we have continued to follow the author's wish to remain anonymous.
A few years ago, we asked the author if they still wanted to remain anonymous. They said: 'Yes, I want to keep my anonymity. But you can tell them that I am well known for my connection to the C language'. It was not until 2001 that another anonymous entry received an award.
BTW: The 1984 winner remains one of my (Landon Curt Noll) all time favorites.
The name used in the posting of the 1st IOCCC winner posting was International Obfuscated C Code Contest or IOCCC for short.
The posting said '1st annual', so in 1985 we held the 2nd IOCCC contest and the tradition continues as the longest running contest on the Internet.
P.S. Part of the inspiration for making the IOCCC a contest goes to the Bulwer-Lytton fiction contest.
P^2.S. See the overall README for more details.
FAQ 0.1: Why are some years missing IOCCC winners?
Some years, such as 1997, 1999, 2002-2003, 2007-2010, 2016-2017, 2021-2023, no IOCCC was held.
While we try to hold the IOCCC every year, sometime the other demands on the IOCCC judges so not permit us to hold a new IOCCC.
The pause during the 2021-2023 period was due to the IOCCC judges developing tools to make is much more likely for the IOCCC to be held in a yearly basis later on.
FAQ 0.2: Why do some IOCCC winners receive the Grand Prize or Best of Show award?
In some years, the IOCCC judges discover a truly amazing IOCCC winner that stands out among all of the other IOCCC entries received that year. For such an IOCCC winner, the IOCCC judges award a "Grand Prize" or "Best of Show award.
In 1984-1987, the grand prize winners are:
Starting from 1988, the entry we liked the most in that year is called "Best of Show". Here are the "Best of Show" entries:
In 1993, 1994 and 1995 the judges were unable to select a clear overall winner. So to give a nod to the entry that had the highest approval ranking from the judges, they used the following awards:
-
1993/rince - Most Well Rounded
-
1994/shapiro - Most Well Rounded
-
1995/leo - Best Use of Obfuscation
These could be considered the 'best entry' for those years with 1 or more other entries that came in close behind.
Section 1: Submitting entries to a new IOCCC
FAQ 1.0: What types of entries have been over-submitted to the IOCCC?
There are types of entries that show up over and over again. The IOCCC judges, and we suspect the public that enjoy viewing the results of the IOCCC, like variety.
While it is possible to win a new IOCCC with one of these over-submitted types of entries, level of the competition from previous IOCCC winners make it more challenging to be successful.
It is also important to note that the guidelines say:
We tend to dislike programs that: are similar to previous winners
maze generator
tic-tac-toe/noughts and crosses/Xs and Os game
solitaire/Othello game
generating small primes (below is the list of all prime related winners)
As you can see, just a list of primes (let alone small primes) does not cut it anymore.
self reproducing program
-
1994/smr - _do not claim your program is the smallest one without seeing this!
-
2000/dhyang - unless you beat this one, your chances are slim
entries that just print "Hello, world!"
...it's so 20th century...
entries that use some complex state machine/table to print something
rot13
pi or e computation
Hints on overused themes
HINT: It is not fatal to send in those types of entries, it is just MUCH HARDER to win. Such an entry would have to do something really unique AND interesting to even make it into the final judging rounds. Entries that reuse these 'worn out' themes frequently lose to other entries that do something different.
HINT: If you really MUST send in an entry based on an 'overused theme', be sure that it is obfuscated in several new and novel ways. Be sure to clearly explain near the beginning of your remarks why you are submitting a entry based on an 'overused theme' and why the judges should not simply toss it out as being boring.
FAQ 1.1: What should I put in my entry's Makefile?
We recommend starting with the sample
Makefile
as found in the mkiocccentry GitHub repo,
(renamed as Makefile of course) as a starting point for your
entry's Makefile.
The Makefile is a file used by the make(1) command that contains
rules and UNIX shell-style commands.
The first and default rule should be the "all" rule and should build your entry's executable file.
If your entry depends on a particular source file name during compilation or execution,
your Makefile should copy prog.c into the desired filename. For example:
If you are not familiar Makefiles, you might consider the following tutorials:
For the make(1) connoisseur: As of 2023, IOCCC judges use GNU
make compatible make(1)
command that is compatible with GNU Make version 3.81.
FAQ 1.2: May I use a different source or compiled filename than prog.c or prog?
While your entry's source filename, as submitted, must be prog.c, your entry's Makefile
may copy prog.c to a different filename as part of the compiling/building process. For example:
all: desired_name
desired_name: desired_name.c
cc desired_name.c -o $@
desired_name.c: prog.c
rm -f $@
cp -f prog.c $@
clobber:
rm -f desired_name.c desired_name
We recommend that the make clobber rule remove files that your entry
creates as part of the compiling/building process.
You may also copy the compiled prog into a different file as part of compiling process.
For example:
different_name: prog
rm -f $@
cp -f prog $@
FAQ 1.3: What platform should I assume for my entry?
Your entry must compile with GCC and run under at least one flavor of UNIX (e.g. Linux or Solaris). To improve chances to win, it should work under both BSD and SysV style UNIX (think stty cbreak), and should not depend on endianness. If it can compile and run on Windows and/or Mac (see 2000/thadgavin for one example, amongst others), even better. Being able to compile with other compilers like clang is also a good thing.
Section 2: IOCCC Judging process
FAQ 2.0: How many entries do the judges receive for a given IOCCC?
By tradition, we do not say.
FAQ 2.1: What should I put in the remarks.md file of my entry?
While you may put in as much or as little as you wish into your entry's
remarks.md file, we do have few important suggestions:
We recommend that you explain how to use your entry. Explain the command line (if any command line options and arguments are used) and any input or actions if applicable.
We highly recommend that you explain why you think your entry is well obfuscated.
For those entries that win the IOCCC, we often use much of text from the
remarks.md file in the Author's remarks section of the README.md file.
For this reason, a well written remarks.md file is considered a plus.
While not required, consider adding bit of humor to your remarks.md
as most people who are not humor impaired, as well as the IOCCC judges
appreciate the opportunity for a fun read as well as a chuckle or two.
What helps:
-
explaining what your entry does
-
how to entice it to do what it is supposed to do
-
what obfuscations are used
-
what are the limitations of your entry in respect of portability and/or input data
-
how it works (if you are really condescending)
What does not help:
-
admitting that your entry is not very obfuscated (you see, the contest is called the IOCCC, not the INVOCCC :-) ); but even if you do not admit it, not very obfuscated entries have a minuscule chance to win (although 2000/tomx is a notable counterexample).
-
mentioning your name or any identifying information in the remark section (or in the C code for that matter) - we like to be unbiased during the judging rounds; we look at the author name only if an entry wins. See the guidelines if this is not clear!
-
leaving the remark section empty.
FAQ 2.2: Why don't you publish non-winners?
Because the publication on the IOCCC site IS the award! Anyone is free to put their IOCCC hopefuls, lookalikes and/or non-winners on their web page for everyone to see.
FAQ 2.3: How much time does it take to judge the contest?
It takes a fair amount of time to setup, run, answer email, process entries, review entries, trim down the set entries to a set of winners, doing the write-up of the winners, announcing the winners, reviewing final edits of the winning entry set, posting the winners, being flamed :-), tell folks who send in late entries to wait until the next contest, etc... It takes a few weekends and a number nights of study and work ... which is hard given that we are busy with many other activities as well.
Note that we do not contact the author if an entry does not compile or does not work as advertised, we might attempt to fix obvious compilation problems or incompatibilities, but no more than that - so be sure that your entry does work on at least a couple different platforms, at least one of them being UNIX or POSIX-conforming.
FAQ 2.4: How many judging rounds do you have?
By tradition, we do not say how many judging rounds we have in a given IOCCC.
We often report when the IOCCC judges start the 1st round, and when usually report when the IOCCC judges start near final judging rounds, and sometimes we also report when we enter what we believe is the final judging round, so you may guess that we have at least 3 rounds. :-) The actual number of rounds is certainly more than 3.
Section 3: Compiling and running IOCCC winners
FAQ 3.0: What Makefile are available to build or clean up IOCCC winners?
In general the best way to compile everything in an entry directory is to run:
make clobber all
If you wish to compile every entry for every year you should go to the top level
directory and run the same command as above, make clobber all.
The all rule will build everything necessary except for the alternate
versions. Every Makefile has an alt rule but it will only do something if an
alternate version exists. To build all the entries along with any alternate code
you can do from the top level directory:
make clobber everything
If you wish to only build alternate code you can do:
make clobber alt
If you wish to not remove the entry binaries and only compile the additional alt versions:
make alt
The following Makefile rules should be in all Makefiles:
- all: build the entry programs (main program and any supplementary program)
- alt: build alternate code
- clobber: clean up object files and all binary files (except for those that are not compiled)
- clean: a simpler version of
clobberthat only removes object files.make clobberdepends oncleanso runningmake clobberwill invokemake clean. - everything: equivalent to
make all alt.
Are there any other rules? You tell us!
NOTE about the above rules: the Makefile default assumes cc which might be a
gcc-based compiler, or a clang-based compiler, or some other compiler. Only by
forcing CC=clang or CC=gcc will one invoke a specific compiler to, say,
enable or disable additional warnings or flags. Even so different versions or
compilers might do different things, have different defects or other issues.
FAQ 3.1: Why doesn't this IOCCC winner compile?
Some winners, particularly winners from long ago, no longer compile on more modern systems because the C language has evolved (i.e. the modern C compilers are much more strict in what they accept as a valid program), or the entry depended on operation system and library features that where common back then but are different/missing today.
Please see the bugs.md file for details about known problems with IOCCC winners. In some cases you may be dealing with a problematic entry. In a few fun cases, the IOCCC does not compile by design!
If you have a fix that makes a minimal impact to the entry, then please consider submitting that change in the form of a pull request. Please see the FAQ 5.1 "How do I report a bug in an IOCCC winner" for details.
In some cases alterinive code has been added that does compile on some or most systems. Check the writeup for the entry for "alt" code and possible ways to compile and run that code. In some cases we replaced the original code (but not the .orig.c file!) with code
that works for modern systems but one can view the original code in the
.orig.c files (sometimes the original code is also in the directory as a
winner.alt.c or prog.alt.c).
FAQ 3.2: Why does a IOCCC winner fail on my 64-bit system?
Unfortunately some older entries are non-portable and require 32-bit support or 32-bit binaries. A problem system here is macOS Catalina (10.15) as as of that version macOS no longer supports 32-bit binaries. If the entry acts on a certain type of binary, say ELF, then that will also be a problem depending on the entry. For example 2001/anonymous requires 32-bit ELF binaries.
There are numerous example entries that require 32-bit binaries. We have tried to note these in both the respective Makefiles and README.md files but it is possible that some were missed. These entries are very likely in the bugs.md file and we welcome any help in making an alternate version for 64-bit systems. Many were fixed to work with modern systems but some are supposed to only work with 32-bit systems so any updated version of these entries should be an alternate version.
Other entries like 2001/herrmann2 now work with 32-bit AND 64-bit systems.
Please see the bugs.md file for the problematic entry in question to see if the problem is known, and if a fix is wanted, consider trying to port the code to a 64-bit system and submitting a pull request with that change. Pull requests that fix such code while trying to minimize the impact of any changes and preserving the spirit of the orignal code are very welcome! Please see the FAQ 5.1 "How do I report a bug in an IOCCC winner" for details.
FAQ 3.3: Why do some IOCCC winners fail to compile under macOS?
If the entry requires gcc and you did not explicitly install gcc in macOS you
will not be able to run or use these entries. This is because macOS gcc is
actually clang, even /usr/bin/gcc.
That being said many (if not most) of these entries have been fixed and some others will be looked at, when found.
In some cases the bugs.md file may note a known macOS problem with an entry. Should you manage to port the entry, and assuming your changes also attempt to preserve the orignal intent of the IOCCC entry, we would encourage you to submit a pull request with your ported code. Please see the FAQ 5.1 "How do I report a bug in an IOCCC winner" for details.
FAQ 3.4: Why does clang or gcc fail to compile an IOCCC winner?
Although we have fixed numerous entries to work with clang (sometimes in an alt version but usually in the program itself) there are some that simply cannot be fixed or if they are fixable they have not yet been fixed (we are working on this but other things have to be done too and all on free time).
This is because clang has some defects where the args of main() are required to be a specific type and some versions of clang allow only 1, 2 or 3 args, not 4, to main(). In the case of types of args many were changed to the right type and then what was main() became another function of the original main() type.
At the same time some entries are not designed to work with clang. There might be alternate code added at some point but as above this depends on free time and other things that have to be done plus remembering to do it.
See if the problem is mentioned in bugs.md. If you have a change that fixes the problem (even if it just a change to the Makefile) that doesn't negatively impact the entry too much, consider submitting that change in the form of a pull request.
Please
see the FAQ 5.1 "How do I report a bug in an IOCCC
winner" for details.
FAQ 3.5: What is this cb tool that is mentioned in the IOCCC?
This was a C beautifier for Unix, both AT&T and Berkeley, but it seems to no
longer be available, code wise, except for Plan 9, but Plan 9 was never used for
judging the IOCCC. A Unix man page for cb
still exists.
FAQ 3.6: An IOCCC winner missed by my terminal application, how do I fix this?
The simplest way to do this is to type reset. If echo was disabled you can get
usually away with stty echo. Sometimes you can also get away with stty sane.
reset does the most but note that it will clear the screen (obviously clear
will too but it won't reset the terminal).
FAQ 3.7: How do I compile and use on macOS, an IOCCC winner that requires X11?
As an example we will use 1993/jonth which works well with macOS.
First of all you will need to install the most recent
XQuartz, preferably on an Apple supported version of
macOS, preferably the most recent version.
Then open the "XQuartz" application (usually located in
/Applications/Utilities/XQuartz.app) by typing at the command line:
open /Applications/Utilities/XQuartz.app
With the "XQuartz" application open you will get an X Window System Manager launched with an Xterm window shell started:
At this point you need to cd to the winning directory and compile it. For example:
And then run the program as directed by the README.md file. For example with
1993/jonth:
Note that you can compile the code in your regular terminal prior to opening XQuartz, should you wish to.
FAQ 3.8: How do I compile an IOCCC winner that requires SDL1 or SDL2?
This depends on your operating system but below are instructions for Linux and macOS with alternative methods for macOS and different package managers with Linux.
Red Hat based linux
Execute one of the following as root or via sudo:
dnf install SDL2 SDL2-devel sdl12-compat sdl12-compat-devel
yum install SDL2 SDL2-devel sdl12-compat sdl12-compat-devel
In the past it was said that one might need to run make like:
make ... SDL2_INCLUDE_ROOT=/usr
or set the following environment variable:
export SDL2_INCLUDE_ROOT=/usr
but this might not be necessary in more modern days especially as we use
sdl-config and sdl2-config which should find the proper paths.
Debian based linux
Execute the following as root or via sudo:
apt install libsdl1.2debian libsdl1.2-dev libsdl2-dev
and then try make all again.
In the past it was said that one might need to run make like:
make ... SDL2_INCLUDE_ROOT=/usr
or set the following environment variable:
export SDL2_INCLUDE_ROOT=/usr
but this might not be necessary in more modern days especially as we use
sdl-config and sdl2-config which should find the proper paths.
Other linux distributions
Use your package manager to install the appropriate packages. Try the search feature of the package manager to determine which packages you need to install. Note that you might have to install both the library and the developmental packages: one for compiling and one for linking / running.
macOS
If you're using macOS there are at least three ways to obtain it. You can download it from the SDL website and install the package. That will not work well for the IOCCC but these will:
MacPorts
If you haven't already, install MacPorts. Then run:
sudo port install libsdl libsdl2
Homebrew
If you have not already done so, install Homebrew.
Then to install SDL and SDL2, execute the following command:
brew install sdl2 sdl12-compat
eval "$(/opt/homebrew/bin/brew shellenv)"
NOTE: there might be extra SDL packages required
In the case that some entries do not work even with SDL1/SDL2 installed it might be that you need additional SDL libraries. See the entry's README.md for details. If something is not noted you're welcome to report it as an issue or fix it and make a new pull request.
FAQ 3.9: How do I compile an IOCCC winner that requires (n)curses?
This depends on your operating system but below are instructions for Linux and macOS with alternative methods for macOS and different package managers with Linux.
Red Hat based linux
Execute one of the following as root or via sudo:
dnf install ncurses ncurses-devel
yum install ncurses ncurses-devel
Debian based linux
Execute the following as root or via sudo:
apt-get install libncurses5-dev libncursesw5-dev
and then try make all again.
Other linux distributions
Use your package manager to install the appropriate packages. Try the search feature of the package manager to determine which packages you need to install. Note that you might have to install both the library and the developmental packages: one for compiling and one for linking / running.
macOS
With macOS it should already be installed. If it is not you might have to do:
xcode-select --install
and agree to the terms and conditions and proceed with the install.
FAQ 3.10: How do I compile and use on macOS, an IOCCC winner that requires sound?
This might depend on the entry but in some cases like 2001/coupard one needs to do more work in order to get it to work. In this case you should be able to use the Swiss Army Knife of sound processing programs, SoX. To install this easily you can use either MacPorts or Homebrew. See below for instructions for each.
Usually the README.md file will explain how to use it in linux so we do not include this here, at least for now.
MacPorts
If you haven't already, install MacPorts. Then run:
sudo port install sox
Homebrew
If you have not already done so, install Homebrew.
Then to install SoX, execute the following command:
brew install sox
eval "$(/opt/homebrew/bin/brew shellenv)"
FAQ 3.10: Why do Makefiles use -Weverything with clang?
While we know that use of -Weverything is generally not recommended
by clang C compiler developers, we do use the -Weverything
option in a certain case in IOCCC winner Makefiles.
The use of -Weverything is limited to when one forces CC=clang or more
generally if the string 'clang' is in $(CC). If $(CC) contains 'gcc' the
'gcc' specific options are run instead.
Users with clang compilers are not required to set CC=clang or equivalent but
when they do, -Weverything is enabled with all of its challenges, pedantic
warnings, and sometimes warnings about things that do not matter, some of which
are frankly frivolous and often downright dubious.
To enable this feature:
make clobber all CC=clang
or:
make clobber all 'CWARN+= -Weverything'
though it should be noted that if one tries -Weverything with compilers that
are not clang they might see something like:
echo 'int main(void) {}' > foo.c ; cc -Weverything foo.c -o foo
cc: error: unrecognized command-line option '-Weverything'
which means that it can't even be compiled. Thus the proper way to do it is the
first way, make clobber all CC=clang.
IOCCC authors who have access to clang might wish to try their
hand at compiling with -Weverything while using a minimum of -Wno-foo
statements. Sometimes there is a technical or pedantic issue that
-Weverything warns about that would merit a change to your C code; often,
however, it is not even possible to fix let alone is it worth it. Of course
if you're running out of bytes due to rule 2[ab] one might not have much choice.
This is something that obfuscators simply sometimes have to deal with!
If you try to minimize the number of -Wno-foo options needed with
-Weverything, please mention this in your remarks about the entry, as the
judges note you attempt to honor it (see also below). In some cases your
obfuscated code will issue warnings with -Weverything no matter what: the
-Wno-poison-system-directories is a common example of this but there are
others as well, sometimes depending on the version of clang.
If you do try for a compile with clang -Weverything, keep on mind that while your
compile environment might be warning free, a different clang version or a
different build environment might still have warnings. For instance the warning
set is different in macOS (which by default is clang: even when run as gcc!)
than linux (due to versions and possibly other things)!
Given that your entry MUST work as documented, you may be safer to
say that your entry keeps the number of warnings and -Wno-foo options while
compiling with clang -Weverything at a minimum. You might want to say the
version number and platform too as an extra safety net. Because if you claim zero
warnings, and we find a warning situation, this may diminish the value of your
entry as it is not as documented. Thus it might be wise to point this out and
if you can test it in multiple platforms (or versions of clang, see
below note) this would be advisable.
NOTE: different versions of clang have other differences as well. For instance
a defect of clang that required numerous entries to be fixed for clang is that it
requires that main()'s arguments to be of a specific type. However some
versions of clang are more strict in the number of args allowed. These reasons
are part of why numerous entries had to be modified so that main() calls
another function instead of doing it all in main() (another reason was that
some entries that recursively called main() caused a crash or otherwise broke
the entry in modern systems). Some entries do not work in clang (or at least do
not work completely) due to these defects, for instance
1989/westley; Cody Boone
Ferguson was able to
get much of it to work and looking at that entry might be of value to your
submissions, at least if you can figure the code out :-). To see the
differences, try from 1989/westley:
make diff_orig_prog
If you have colordiff try:
make DIFF=colordiff diff_orig_prog
Alternatively you can try:
git diff d2a42f42e8f477f29e9d5ed09ce2bb349eaf7397..eb9e69fde657acc8c85a618a8a99af4c2f93b21d westley.c
As you can see, using clang has some additional problems to work out but if
you can get your entry to work well in clang it might very well be considered
better than other entries.
Section 4: Changes made to IOCCC winners
FAQ 4.0: Why are some winning entry remarks incongruent with the winning IOCCC code?
It is very likely in this case that the code was fixed to work for modern
systems as part of the reworking of the website. If you have this problem in
some entries you should look at the original code as in winner.orig.c or
prog.orig.c. winner is the directory name. For instance, one of Landon's
favourite entries of all time is 1984/mullender and
the winner there would be mullender. Sometimes the original is in an alt
version like winner.alt.c or prog.alt.c. In fact it is advisable to look at
the original code when reading the author's (and sometimes authors') remarks.
FAQ 4.1: Why were some calls to the libc function gets changed to use fgets?
Some may wonder: "Doesn't this tamper with the entry too much?"
A fine line indeed has to be drawn here but it was decided that it is worth it because of alarming warnings that can be displayed, in some systems at runtime interspersed with the output of the program.
For instance in macOS the entry 1990/tbr would output the warning in such a way that caused confusing output for the entry, looking like:
$ ./tbr
$ warning: this program uses gets(), which is unsafe.
# nothing here, what to do?
In some cases changing the code to use fgets() is not so easy to fix and in
one case at least there is an alternate version that has the fix instead due to
a problem it creates (correct output but segfaults after the output in one of
the forms of input).
In some cases it is not possible to fix or at least it is highly unlikely and so
those have mainly not been touched except one that has had the buffer size
increased (which could be done for others that are not possible to change to
fgets() though this has not been done).
Some entries can be made to look almost identical to the original entry. For
instance the fix to 1988/reddy required only a single
#define be added.
In the future we, the judges, would prefer that entries use fgets() to prevent
these problems.
NOTE: due to 'compatibility reasons' fgets() stores the newline and gets()
does not. We're not sure how this is compatibility but either way it can cause a
problem and it is this that has complicated most of the fixes though again some
can look almost identical.
FAQ 4.2: What was changed in an IOCCC winner source code?
We have set up make rules to easily do see what was changed in the IOCCC
winner source. Using the Makefile in the winner directory, use
one of the following make(1) rules:
The following make rules exist to make a difference:
make diff_orig_prog:- This rule will show the diff of the original source to the
current source (that is
entry.orig.ctoentry.c).
- This rule will show the diff of the original source to the
current source (that is
make make diff_alt_orig:- This rule will show the diff of the alt code to the original
code (that is
entry.alt.ctoentry.orig.c). If no alt code exists nothing will be shown.
- This rule will show the diff of the alt code to the original
code (that is
make diff_alt_prog:- This rule will show the diff of the alt code to the entry as it
stands (that is
entry.alt.ctoentry.c).
- This rule will show the diff of the alt code to the entry as it
stands (that is
make diff_orig_alt:- This rule will show the diff of the original code to the alt code
(that is
entry.orig.ctoentry.alt.c).
- This rule will show the diff of the original code to the alt code
(that is
make diff_prog_alt:- This rule will show the diff of the entry to the alt code (that is
entry.ctoentry.alt.c).
- This rule will show the diff of the entry to the alt code (that is
make diff_prog_orig:- This rule will show the diff of the entry to the original code (that is
entry.ctoentry.orig.c).
- This rule will show the diff of the entry to the original code (that is
For instance one of Landon's all time favourite entries is
1984/mullender so the file names would be:
mullender.orig.c, mullender.alt.c and mullender.c. For later years, it
would be instead prog.orig.c, prog.alt.c and prog.c.
Note that you might see something like:
make: [Makefile:170: diff_orig_prog] Error 1 (ignored)
at the end of the output but this is completely normal if there are differences.
If the alt code is the same as the original, say with 1984/anonymous, then naturally there is no point in running the rule and the same applies for all the other rules but this system allows for easily seeing the diffs.
As some examples we'll first look at one that has really long lines which
will make it harder to see what is different,
2001/anonymous. What you would do is cd 2001/anonymous and then do:
make diff_orig_prog
and then be really confused! :-)
But for an entry like 1991/dds, you can see the
differences much more easily. 1991/dds is a good example where it's very
simple to see what is different as it's just a couple lines.
You might be quite surprised how little some entries had to be changed and at the same time how much other entries had to be changed, often with quite complex differences! In some cases if the line is rather long, like the above mentioned one, it will be harder to see what changed but in other cases like 1984/decot or 1986/wall it's a lot easier.
Well, at least it's easier see the differences on a line-by-line basis but maybe not what actually changed, especially since it's easier to know what was fixed when you have compiler errors :-) (though there are, as noted, some examples where it's quite easy to see the differences).
1991/dds is also a good example to see the alt difference
very easily. To do that cd 1991/dds and then do:
make diff_alt_prog
and you'll see a single line changed and very simply.
Tip: if you have colordiff installed it's a lot easier to see the differences
To use these rules but provide a different diff, for instance colordiff,
just do:
make DIFF=colordiff diff_orig_prog # for orig to prog diff
make DIFF=colordiff diff_alt_prog # for alt to prog diff
Obviously if you want to view the alt code or the orig code you can just open the files as described above.
FAQ 4.3: Why do author remarks sometimes not match the source?
This is very likely to happen when an entry was fixed for modern systems. When
you look at the remarks of the author you should look at the prog.orig.c or
the winner.orig.c file. You might also find value in the above diff make
rules.
FAQ 4.4: What is the meaning of the file ending in .orig.c in IOCCC winners?
Due to the fact that the original code has sometimes had to change these files are the original winning entry or as close to as possible to the original that we can find.
Section 5: Updating or correcting IOCCC web site content
FAQ 5.0: Why does an IOCCC winner fail to compile or or fail run?
What may have worked years ago may not work well or work at all today. Please note that the IOCCC judges do NOT support IOCCC winners. Nevertheless, there may be a number of reasons why an IOCCC winner may fail to compile or run well or fail to run on your system.
In some cases the American National Standards Institute's ANSI C committee has damaged the C standard to the point where perfectly valid C programs no longer compile with modern compilers. As such some old IOCCC winners cannot no longer be compiled with modern compilers.
In some cases programs that may have worked on an old computer system longer work on modern computers. Some IOCCC winners do not work well, or no longer work on modern computers or modern operating systems. Some IOCCC winners fail to compile under clang, or gcc. Some IOCCC winners require operating system services that may not be present on your system.
In some cases the IOCCC winner simply has bugs or (Mis)features.
If you are having problems compiling or running an IOCCC winner, we recommend that you look in bugs.md to see if there is a known bugs or (Mis)feature. In some cases what you may think is a bug is actually an feature that was intentionally written by the authors. In some cases the problem is well known and we are looking for someone to attempt to fix it.
In some cases there is an alternate version of the IOCCC winner that you may wish to try.
It also possible that you may have discovered a bug in an IOCCC winner. If so, you are invited to try an fix the IOCCC winner and submit that fix by way of a GitHub pull request. Please see the FAQ 5.1 "How do I report a bug in an IOCCC winner" for details.
FAQ 5.1: How do I report a bug in an IOCCC winner?
We do not 'maintain' the contest winners as such. The code is made available on an 'AS IS' basis. If you have a FIX for an entry, we suggest that you submit your fixes in a GitHub pull request as we welcome pull requests that have a minimal impact on the entry while improving the portbility, functionality, and/or addressing known problems.
If you do submit a pull request, we ask that each pull request address just one IOCCC winner at a time.
Note that just because you have a fix does not mean it'll be accepted. This might be because the author objects or it doesn't fit in some way or another. Of course if the entry does not work we'll certainly be more inclined to accept the fix. If it is accepted we'll be happy to credit you in the entry's README.md file. If you're a previous winner we will happily link to your entries; if you're not we can link to your website if you wish.
More generally please see the file how-to-bugfix.md. Note that this file is not a tutorial on how to fix X, Y and Z problems but rather what to do to get the fix in.
Section 6: Miscellaneous IOCCC
FAQ 6.0: How did an entry breaks the size rule 2, win the IOCCC?
As entries have been fixed it is entirely possible that some of the entries no longer fit within the year's size restrictions. Invariably the length of columns and/or number of rows have also changed.
The winner.orig.c file contains the original source code that was
subjected to rule 2 of the given IOCCC. You may also wish to see
the /archive directory where you can find all the
original winning entries as compressed tar files for a given year.
In some cases the entry may have abused rule 2 and declared an "abuse of the rules" (although now blatant abuse of the rules to get around rule 2 size limits is discouraged).
FAQ 6.1: Is there a list of known bugs and misfeatures of IOCCC winners?
Yes! Please see bugs.md for a list of known bugs and/or issues of a variety of kinds.
Note that just because an entry is not in the bugs file does not mean there is not an issue and note that some issues are simply missing files, dead URL(s) or something like that.
FAQ 6.2: May I mirror the IOCCC web site?
We are not accepting mirror requests at this time, sorry. However you are free to fork the IOCCC winner repo. We do ask that your fork keep up to date with the latest changes when possible.
FAQ 6.3: May I use parts of the IOCCC in an article, book, newsletter, or instructional material?
While IOCCC judges look favorably on most requests to use IOCCC material, we request that you ask the IOCCC judges first.
Please send your request using the instructions on the contacting the IOCCC Judges page.
FAQ 6.4: Why do you sometimes use the first person plural?
As a precedent for first person plural, we may sight Two-, Three-, and Four-Atom Exchange Effects in bcc in 3He and the co-authorship of F. D. C. Willard as well as the APS New Open Access Initiative.
The number of IOCCC judges has always been "> 1" such that IOCCC judges often prefer to themselves in the plural, sometimes in the common plural, sometimes in the first person plural, there may be some who reject such a practice. Therefore please consider that when you believe that just one of the IOCCC judges is in action, you may consider that F. D. C. Willard has been consulted, agreed, and has authorized the statement thus allowing the in the common plural to be used without offense.
And while some might claim that F. D. C. Willard died in 1982, we suggest that the Schrödinger's cat superposition may still be in effect and the 1982 report of death was an exaggeration.
p.s. Here is an image of F. D. C. Willard: