Obfuscated Game of Life in 9 lines of C (opens in new tab)

(github.com)

66 pointsjackhammer202212y ago23 comments

23 comments

16 comments · 8 top-level

babuskov12y ago· 4 in thread

Nice explanation of each line is here:

https://github.com/duckythescientist/obfuscatedLife/blob/mas...

Code is obfuscated more than needed to run. It starts with something simple like this:

"I abuse 2's complement math to initialize it as -1"

Instead of: __ = -1 The code reads: __=~__+__

... and then gets more and more bizarre.

twoodfin12y ago

Isn't reading an uninitialized variable that could have been given a "register" qualifier undefined behavior? That is, the program never takes the address of __.

babuskov12y ago

In most cases, a program would just read from "dirty" memory and you might get a random value. In this case, whatever bits are there, they "add up" to -1, so it just works.

Madrigal12y ago

Yes, it is undefined behavior by the standard, but most compilers will give you some random value and you will get the answer that GhotiFish states.

GhotiFish12y ago

lets say __ is 0x00101101

then it's ~__+__

   0x00101101
  +0x11010010

You can see how that always works.

1 more reply

carlosdp12y ago· 2 in thread

On a cool side note, I don't know if this is old, but if you Google "Conway's Game of Life", an actual game of life is run on the page: https://www.google.com/#q=conway's+game+of+life

Someone12y ago

That's old. Nowadays, it would only be impressive if it were written in pure CSS.

Yes, that's a snark, but also a challenge to those with time on their hands. Bonus points if your solution grows the universe to contain, e.g., an escaping glider.

lloeki12y ago

> if it were written in pure CSS

> also a challenge

Is CSS turing-complete? If not, game over.

1 more reply

cgcardona12y ago· 1 in thread

I'm sure many would complain about the obfuscated nature of the code. I however find it strangly beautiful. It has the appearance of a strand of DNA and then one marvels at all of the complexity hidden in these cryptic lines.

To see it:

`git clone https://github.com/duckythescientist/obfuscatedLife.git

cd obfuscatedLife

gcc life.c

./a.out`

Here is a screenshot[1] for anyone who didn't run the code. However a screenshot hardly does the dynamic nature of it justice.

[1] http://imgur.com/hWzEWAe

hkmurakami12y ago

Well, this is a submission to the IOCCC, so I don't think anyone will complain about the code's obfuscated nature :)

deletes12y ago· 1 in thread

So much effort is ruined with the usage of usleep. Obfuscated C should be portable!

ekr12y ago

What's not portable about the usleep function? It's in the POSIX standard for portable operating systems (http://pubs.opengroup.org/onlinepubs/7990989799/xsh/usleep.h...). It doesn't get much more portable than that.

Edit: Apparently, it has indeed been removed from SUSv4.

Aardwolf12y ago

And to run this program in a single line of bash on Unix systems (does create a ./a.out file):

  echo 'int main(){int _[2048],O=(int)&O,__=~__+__;while((__=-~__)^2048)__[_]=(O=(O*0x41C64E6D+12345)&0x7fffffff)&1024?1<<5:0;while(usleep('"'"'d'"'"'<<'"'"'\n'"'"'),__+=~__){while((__=-~__)^8192){if(_[((__>>2)+2048+"\x01?@A"[__%4])%04000]&1<<5)*(_+(__>>2))=-~_[__>>2];if(_[((__>>2)+04000-"\x01?@A"[__%4])%2048]&1<<5)*(_+(__>>2))=-~_[__>>2];if(__%4==3)_[__>>2]|=_[__>>2]^'"'"'\"'"'"'&&_[__>>2]^'"'"'#'"'"'?((_[__>>2]^3)?0:1<<4):1<<4;};while((__=-~__)^10240)if(putchar((_[__%2048]=_[__%2048]<<1&1<<5)?'"'"'X'"'"':'"'"' '"'"'),!(63^__%0100))putchar(10);}};' | gcc -xc - && ./a.out
  
  .

lelandbatey12y ago

Youtube link for those who are unwilling or unable to download and compile yourself:

http://www.youtube.com/watch?v=LFx46bAq-_E

As well, for those that don't want to use youtube, you can view/stream the raw video here:

http://lelandbatey.com/files/Obfuscated%20C%20-%20Game%20Of%...

iamstef12y ago

Fun obfuscated version in ruby.

https://github.com/stefanpenner/obfcuscatedLife.rb/blob/mast...

and for those crazy people who ever far to trusting:

  curl https://raw.github.com/stefanpenner/obfcuscatedLife.rb/master/game_of_life.rb | ruby

julienchastang12y ago

In APL, it is one line of code http://catpad.net/michael/apl/. Whether it is obfuscated or not is a matter of interpretation.

j / k navigate · click thread line to collapse

23 comments

16 comments · 8 top-level

babuskov12y ago· 4 in thread

Nice explanation of each line is here:

https://github.com/duckythescientist/obfuscatedLife/blob/mas...

Code is obfuscated more than needed to run. It starts with something simple like this:

"I abuse 2's complement math to initialize it as -1"

Instead of: __ = -1 The code reads: __=~__+__

... and then gets more and more bizarre.

twoodfin12y ago

Isn't reading an uninitialized variable that could have been given a "register" qualifier undefined behavior? That is, the program never takes the address of __.

babuskov12y ago

In most cases, a program would just read from "dirty" memory and you might get a random value. In this case, whatever bits are there, they "add up" to -1, so it just works.

Madrigal12y ago

Yes, it is undefined behavior by the standard, but most compilers will give you some random value and you will get the answer that GhotiFish states.

GhotiFish12y ago

lets say __ is 0x00101101

then it's ~__+__

   0x00101101
  +0x11010010

You can see how that always works.

1 more reply

carlosdp12y ago· 2 in thread

On a cool side note, I don't know if this is old, but if you Google "Conway's Game of Life", an actual game of life is run on the page: https://www.google.com/#q=conway's+game+of+life

Someone12y ago

That's old. Nowadays, it would only be impressive if it were written in pure CSS.

Yes, that's a snark, but also a challenge to those with time on their hands. Bonus points if your solution grows the universe to contain, e.g., an escaping glider.

lloeki12y ago

> if it were written in pure CSS

> also a challenge

Is CSS turing-complete? If not, game over.

1 more reply

cgcardona12y ago· 1 in thread

To see it:

`git clone https://github.com/duckythescientist/obfuscatedLife.git

cd obfuscatedLife

gcc life.c

./a.out`

Here is a screenshot[1] for anyone who didn't run the code. However a screenshot hardly does the dynamic nature of it justice.

[1] http://imgur.com/hWzEWAe

hkmurakami12y ago

Well, this is a submission to the IOCCC, so I don't think anyone will complain about the code's obfuscated nature :)

deletes12y ago· 1 in thread

So much effort is ruined with the usage of usleep. Obfuscated C should be portable!

ekr12y ago

Edit: Apparently, it has indeed been removed from SUSv4.

Aardwolf12y ago

And to run this program in a single line of bash on Unix systems (does create a ./a.out file):

  echo 'int main(){int _[2048],O=(int)&O,__=~__+__;while((__=-~__)^2048)__[_]=(O=(O*0x41C64E6D+12345)&0x7fffffff)&1024?1<<5:0;while(usleep('"'"'d'"'"'<<'"'"'\n'"'"'),__+=~__){while((__=-~__)^8192){if(_[((__>>2)+2048+"\x01?@A"[__%4])%04000]&1<<5)*(_+(__>>2))=-~_[__>>2];if(_[((__>>2)+04000-"\x01?@A"[__%4])%2048]&1<<5)*(_+(__>>2))=-~_[__>>2];if(__%4==3)_[__>>2]|=_[__>>2]^'"'"'\"'"'"'&&_[__>>2]^'"'"'#'"'"'?((_[__>>2]^3)?0:1<<4):1<<4;};while((__=-~__)^10240)if(putchar((_[__%2048]=_[__%2048]<<1&1<<5)?'"'"'X'"'"':'"'"' '"'"'),!(63^__%0100))putchar(10);}};' | gcc -xc - && ./a.out
  
  .

lelandbatey12y ago

Youtube link for those who are unwilling or unable to download and compile yourself:

http://www.youtube.com/watch?v=LFx46bAq-_E

As well, for those that don't want to use youtube, you can view/stream the raw video here:

http://lelandbatey.com/files/Obfuscated%20C%20-%20Game%20Of%...

iamstef12y ago

Fun obfuscated version in ruby.

https://github.com/stefanpenner/obfcuscatedLife.rb/blob/mast...

and for those crazy people who ever far to trusting:

  curl https://raw.github.com/stefanpenner/obfcuscatedLife.rb/master/game_of_life.rb | ruby

julienchastang12y ago

In APL, it is one line of code http://catpad.net/michael/apl/. Whether it is obfuscated or not is a matter of interpretation.

j / k navigate · click thread line to collapse