Merge pull request #2268 from xexyl/sds2004-readme-fix

2004/sds/README_sds.txt

@@ -0,0 +1,127 @@
+## To build:
+
+```sh
+make
+```
+
+
+### Bugs and (Mis)features:
+
+The current status of this entry is:
+
+```
+STATUS: INABIAF - please **DO NOT** fix
+```
+
+For more detailed information see [2004 sds bugs](../../bugs.html#2004_sds).
+
+
+## To use:
+
+```sh
+./sds
+```
+
+
+## Try:
+
+```sh
+./try.sh
+```
+
+
+## Judges' remarks:
+
+Why not use the program to hide another program in the program? It
+must have seemed reasonable at the time.
+
+The ability to hide a message in plain text is quite charming, really.
+We must admit to a bit of uncertainty about where you'd find such
+messages, or how useful they'd be.  Or, of course, whether all those
+horribly badly formatted emails spammers send might contain secret
+messages.  Annoyingly, it's a little too obvious that SOMETHING has
+been done to a message for us to hide one in the remarks.  :)
+
+
+## Author's remarks:
+
+[Steganography](https://en.wikipedia.org/wiki/Steganography) is the term for the
+family of techniques used for hiding information within other information.
+Today, it has many real world uses, particularly for digital watermarking.
+
+This program uses a steganographic technique to hide information in any text
+file.  The specific technique used is aimed at writers of obfuscated programs
+for the IOCCC, as the hidden information is encoded in the whitespace in the
+source file.  As we know, there are up to an additional 2048 characters of
+whitespace available to entrants to the IOCCC, so it turns out that this is an
+ideal place to hide things.
+
+The program as provided is the steganographic decoder.  Rather than
+provide a separate encoding program, you should not be surprised to
+learn that I opted to steganographically hide the encoder inside the
+decoder.
+
+Try it out.  Compile the program, then type
+
+```sh
+./sds < sds.c
+```
+
+You should see the encoder program displayed.  Now save it, like:
+
+```sh
+./sds < sds.c > encoder.c
+```
+
+Then compile `encoder.c`.  You now have the complete system ready.
+
+The encoder expects to get a filename as an argument.  This filename
+is the name of the file containing the information to be hidden.  It
+expects the file in which to hide the information to be on the
+standard input, and will output the results on the standard output.
+
+You can use it like this (assuming you have a file called remarks):
+
+```sh
+echo 'Hello, World!' > message
+./encoder message < remarks > remarks_msg
+```
+
+Then to decode:
+
+```sh
+./sds < remarks_msg
+Hello, World!
+```
+
+C programs are mostly unaffected by adding steganographic content,
+but it is possible in certain circumstances for whitespace to be
+changed inside strings where it should be left alone.  Plain text
+files are good candidates for hiding information in, but the added
+spacing may render the text somewhat difficult to read.
+
+
+### Obfuscation
+
+This program is obfuscated in a number of ways:
+
+* The code is all but impossible to read due to the spacing.
+* The algorithm is well hidden in the code due to copious red-herrings.
+* The long expressions cause indentation tools to give poor results.
+* And good old fashioned ternary operators are the icing on the cake.
+
+### Compiling the program
+
+The program (and the encoder program) should compile on any
+reasonable compiler.  In particular, they are known to compile under
+GNU C.
+
+
+## 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/

2004/sds/try.sh

@@ -30,10 +30,10 @@ echo 1>&2
 make encoder 2>/dev/null
 echo 1>&2
 
-echo "$ ./encoder README.md <sds.c | tee sds_msg.c" 1>&2
+echo "$ ./encoder README_sds.txt <sds.c | tee sds_msg.c" 1>&2
 read -r -n 1 -p "Press any key to continue (space = next page, q = quit): "
 echo 1>&2
-./encoder README.md <sds.c | tee sds_msg.c | less -rEXFK
+./encoder README_sds.txt <sds.c | tee sds_msg.c | less -rEXFK
 
 read -r -n 1 -p "Press any key to run: make sds_msg 2>/dev/null: "
 echo 1>&2
@@ -55,15 +55,15 @@ echo 1>&2
 echo 'Hello, World!' > message
 echo 1>&2
 
-echo "$ ./encoder message < README.md | tee remarks.md" 1>&2
+echo "$ ./encoder message < README_sds.txt | tee remarks.md" 1>&2
 read -r -n 1 -p "Press any key to continue (space = next page, q = quit): "
 echo 1>&2
-./encoder message < README.md | tee remarks.md | less -rEXFK
+./encoder message < README_sds.txt | tee remarks.md | less -rEXFK
 echo 1>&2
 
-read -r -n 1 -p "Press any key to run: diff remarks.md README.md (space = next page, q = quit): "
+read -r -n 1 -p "Press any key to run: diff remarks.md README_sds.txt (space = next page, q = quit): "
 echo 1>&2
-diff remarks.md README.md | less -rEXFK
+diff remarks.md README_sds.txt | less -rEXFK
 echo "Did you notice how similar they are?" 1>&2
 echo 1>&2
 

thanks-for-help.html

@@ -2185,6 +2185,9 @@ fast in modern systems, especially the scrolling text of
 <p>Cody also added the <a href="2004/schnitzi/try.sh">try.sh</a> script.</p>
 <h2 id="sds-index.html"><a name="2004_sds"></a><a href="2004/sds/sds.c">2004/sds</a> (<a href="2004/sds/index.html">index.html</a>)</h2>
 <p><a href="#cody">Cody</a> added the <a href="2004/sds/try.sh">try.sh</a> script.</p>
+<p>Also, after the README.md file had copyright changes, it broke the script so
+Cody made a copy of the older README.md file into <code>README_sds.txt</code> and added that
+to the repo for the script instead.</p>
 <h2 id="vik2-index.html"><a name="2004_vik2"></a><a href="2004/vik2/vik2.c">2004/vik2</a> (<a href="2004/vik2/index.html">index.html</a>)</h2>
 <p><a href="#cody">Cody</a> fixed this to compile in Linux. Although it compiled cleanly in macOS (and
 BSD?) the code failed to compile at all in Linux due to:</p>

thanks-for-help.md

@@ -3166,6 +3166,10 @@ Cody also added the [try.sh](2004/schnitzi/try.sh) script.
 
 [Cody](#cody) added the [try.sh](2004/sds/try.sh) script.
 
+Also, after the README.md file had copyright changes, it broke the script so
+Cody made a copy of the older README.md file into `README_sds.txt` and added that
+to the repo for the script instead.
+
 
 ## <a name="2004_vik2"></a>[2004/vik2](2004/vik2/vik2.c) ([index.html](2004/vik2/index.html))