What's the coolest hack you've seen or done? [closed]

Answer 1

I made a divide-by-eight counter out of pneumatic valves in college in order to get exempted from the remainder of the pneumatics course.

Answer 2

I wrote a simple Windows batch file to let me quickly play tracks matching some pattern from my music library (on f: drive) on a painfully slow machine (opening iTunes takes about 3 minutes on this machine!). It supports regular expressions via the findstr command and uses mplayer to play the tracks. All I have to do is press Windows+R and type:

play u2

or:

play "neighbo.+rhood"

or:

play "blink[0-9][0-9][0-9]"

The batch file is like this, in play.bat.

cd /d f:
findstr /I /R %1 dirlist.txt > playlist.txt
mplayer -playlist playlist.txt

Both mplayer and play.bat should be added to your path.

Answer 3

Duff's Device. Does that count? :)

Answer 4

The Fast Inverse Square Root-- a bizarre little routine that somehow manages to compute the inverse square root of something, but you'd never guess that from looking at it.

http://betterexplained.com/articles/understanding-quakes-fast-inverse-square-root/

Answer 5

I once hacked together a simple dos-style commandline for the psion 3a during a university lecture. It could only do basic directory listing, browsing, copy & move, but it looked the part - full screen a small font.

Oh, and I programmed pong for the 68008 with pots for input and an oscilloscope for output. Not that hard using a dev board, but there was something cool about playing it on an osc.

Answer 6

Not by me:

#include <stdio.h>
#include <string.h>
int main(int argc, char *argv[]){
  int i;

  printf("((((");
  for(i=1;i!=argc;i++){
    if(     strcmp(argv[i], "^")==0) printf(")^(");
    else if(strcmp(argv[i], "*")==0) printf("))*((");
    else if(strcmp(argv[i], "/")==0) printf("))/((");
    else if(strcmp(argv[i], "+")==0) printf(")))+(((");
    else if(strcmp(argv[i], "-")==0) printf(")))-(((");
    else                             printf("%s", argv[i]);
  }
  printf("))))\n");
  return 0;
}