Landon Curt Noll
2b92c89be8
Entry source is now prog.c for IOCCC years 2014 thru 2020, or is now dirname.c IOCCC years 1984 thru 2013. To achieve this state, we renamed the following: renamed: 2004/hibachi/src/hibachi.c -> 2004/hibachi/hibachi.c renamed: 2012/omoikane/nyaruko.alt.c -> 2012/omoikane/omoikane.alt.c renamed: 2012/omoikane/nyaruko.alt2.c -> 2012/omoikane/omoikane.alt2.c renamed: 2012/omoikane/nyaruko.c -> 2012/omoikane/omoikane.c renamed: 2012/omoikane/nyaruko.orig.c -> 2012/omoikane/omoikane.orig.c Modified `bin/subst.entry-index.sh` to add to entry `index.html` file, links to the `Makefile` and the _C code_ to the top navigation bar. Changed `bin/subst.entry-index.sh` VERSION from "1.2.2 2024-02-25" to "1.3 2024-03-02". Moved printing the Inventory link in the top navigation bar from `bin/subst.entry-navbar.awk` to `bin/subst.entry-index.sh`. Changed `bin/subst.entry-navbar.awk` VERSION from "1.0.1 2024-02-23" to "1.1 2024-03-02". Moved printing the Inventory link in the top navigation bar from `bin/subst.year-navbar.awk` to `bin/subst.year-index.sh`. Changed `bin/subst.year-index.sh` VERSION from "1.0 2024-02-11" to "1.1 2024-03-02". Changed `bin/subst.year-navbar.awk` VERSION from "1.0 2024-02-11" to "1.1 2024-03-02". Added location names (both default and common) to `author.html`. Changed `tmp/gen_author_json.sh` VERSION from "1.0 2023-06-06" to "1.1 2024-03-04". Added location names (both default and common) to `author.html`. Changed `bin/gen-authors.sh` VERSION from "1.2 2024-03-09" to "1.3 2024-03-04". The manifest and the resulting `.entry.json` files have been changed for `2004/hibachi` and `2012/omoikane`. The Makefiles for `2004/hibachi` and `2012/omoikane` copy the source file into the "previously used location". The `make clobber` rule removes the copied source. The `.gitignore` files have been updated accordingly. Improved how the concept of IOCCC terms _entry_, _author_ and _submission_ are used in markdown files. Links to markdown files (files ending in .md) within the repo were changed to link to HTML files (files ending in .html). Special cases where `README.md` became `index.html` were modified accordingly. Fixed URL for `bugs.html` in Makefile comments. Fixed name of `bin/sgi.sh` referenced in comments in `.gitignore` files. Links to locations within the repo are now relative. For example a link to `/contact.html` may become `../contact.html' or '../../contact.html` depending on the directory level of the markdown file. Nearly all links with absolute URLs under _https://www.ioccc.org_ or `https://ioccc-src.github.io/temp-test-ioccc_ have been changed to relative paths within the repo. Some exceptions to this (such as referring to a GitHub repo) were preserved. Fixed a number of inside `faq.md` and `bugs.md`. Added HTML name tags (in the form of an _entry_id_) for each entry referenced in `bugs.md`. Fixed links from outside of `bugs.html` into `bugs.html` accordingly. Where FAQ entries are referenced, a named tag is used so that if a FAQ is ever renumbered, links outside of `faq.html` will still work. Changed the _inventory_order_ of a compressed tarball from _300_ to _100000_. While this may have been done for the manifest, this changed had not yet been propagated into the `.entry.json` files. Links to web sites that were in the for <URL> are now [URL](URL). Performed `name www` to process all of the above. Improved format of `authors.html`. Full names are now bold. Location codes are now links back into `location.html` and location names (both default and common) are now italics. Added _author_handle_ each author. Changed `bin/gen-authors.sh` VERSION from "1.1 2024-02-25" to "1.2 2024-03-09". Improved format of `location.html` as location codes are now bold, author counts in a given location are now bold, and location names (both default and common) are now italics. Changed `bin/gen-location.sh` VERSION from "1.0.1 2024-02-23" to "1.1 2024-03-04". Added italic location name after location code in entry `index.html` files. Changed `bin/output-index-author.sh` VERSION from "1.4.1 2024-02-23" to "1.5 2024-03-04". Added _Location of authors_ to the sidebar as a link to `location.html`. TODO: While nearly all of the above mentioned changes are likely correct, they likely introduced a few errors that need correcting.
To build:
make
Bugs and (Mis)features:
The current status of this entry is:
STATUS: INABIAF - please **DO NOT** fix
For more detailed information see 2000 primenum bugs.
To use:
echo n | ./primenum n
NOTE: n is an integer.
Try:
./try.sh
Judges' remarks:
Don't read the author remarks until you're ready for the spoiler. Just stop and read the program; it won't take long. Once you've figured out what it does, run it. It may surprise you.
This entry won, not because the obfuscation is impenetrable, but because it successfully fooled half of the judges, including me.
Author's remarks:
Description
For 15 years, IOCCC entries have obfuscated programs using esoteric, difficult-to-interpret, confusing algorithms. This entry finally bucks that trend and obfuscates in the most "obvious" way possible: by painstakingly describing the algorithm in clear pseudocode. Even novice programmers will recognize that the program should find and print prime numbers up to a given number (as specified on the command line).
But novice programmers especially know that mistakes are often made in
translating pseudocode to real code, often resulting in programs with
unexpected and confusing output. Clearly, the program contains several
syntax "mistakes" (e.g. LessThanOrEqualTo) and blatant "errors" (e.g.
Zero). This program clearly requires "debugging."
As a result of these "bugs", the program does not calculate primes at all.
Instead, the program reads input from stdin and returns garbled text on
stdout. Fortunately, you can recover the original message simply by
running the program a second time. Try:
./primenum n < textfile | ./primenum n > textfile2
diff textfile textfile2
where n is the same number (modulo 64). So, the prime number generator is actually a simple text encoder/decoder! Of course, don't forget that argument, otherwise the "bugs" in the program will cause it to crash!
Features
-
The program attempts to mislead the reader into thinking that it generates prime numbers. It does this by:
- describing a correct algorithm in pseudocode;
- using partially correct conversion of pseudocode to real code;
- using suggestive variable names; and
- using a suggestive program name.
-
The program demonstrates a novel method of abusing the C preprocessor.
-
Determining how the filter algorithm works is left as an exercise to the reader.
-
OK, so running it through the preprocessor strips away the prime number front. But ye be warned: "not a11 variab1es1es are identica1" :-)
-
Other features include
- useless variables
- useless if
- a for loop that's used as an if statement
- dependence on the high bit being 0
-
Try also
echo THIS MESSAGE IS IN ALL CAPS | ./primenum 32
Copyright and CC BY-SA 4.0 License:
This file is Copyright (c) 2023 by Landon Curt Noll. All Rights Reserved. You are free to share and adapt this file under the terms of this license:
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
For more information, see: https://creativecommons.org/licenses/by-sa/4.0/