Most elementary use of C - Silver award

Tsukasa Hamano

Judges' comments:

To build:

make hamano

To run:

./hamano < textfile > output.pdf


./hamano < hint.text > hint.pdf

# You can read output.pdf with PDF reader
acroread hint.pdf
# or
evince hint.pdf

# deobfuscate
gcc -xc hint.pdf -o hint

# Of course, You can obfuscate c code
echo 'void main(){puts("Hello World!");}' | ./hamano > hello.pdf
gcc -xc hello.pdf -o hello2
./hello2 | gcc -xc - -o ./hello3

Selected Judges Remarks:

This entry treads into a new territory for IOCCC - generating PDF files.

The originally submitted entry could have been thought of as a “Best abuse of Ghostscript” winner. :-)

The source code and rendered pages are obfuscated for humans (where is the font?), and the submitted entry created PDF files that left Ghostscript confused.

The results can be viewed with Acrobat Reader, evince and Apple’s Preview.

The updated version can also be viewed using Ghostscript.

There is something strange about the little flags in the output. A search of English literature will provide a hint. The conclusion you might draw is too elementary. :-)

So what do those flags really mean?

The [Dancing men algorithm][1] might be useful.

Don’t forget to take a look at the generated PDF, perhaps you might even want to compile the output with a C compiler. When you run it, what does it output?

Author’s comments:

This program obfuscate text file into PDF file with Dancing men algorithm.

Probably, the output PDF file is compliant with PDF 1.3. And also available to compile as C code.

I’ve been tested with GCC 4.7 and Clang 3.0 on Linux, and following PDF Reader:


This program is obfuscated by using classical methods. But can you find out the embedded font from fragmented glyph?

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