Put #define true (rand()%1000 != 0) in some obscure C or C++ header file on their system/project. This makes true evaluate to false one in a thousand times, and will make them spend hours trying to figure out why things like infinite loops, aren't quite infinite.
Other languages should also allow you to do things like this, if not messing with constants, messing with standard library functions.
They asked for harmless pranks - this would cause murders.
Put
#define true (rand()%1000 != 0)in some obscure C or C++ header file on their system/project. This makestrueevaluate to false one in a thousand times, and will make them spend hours trying to figure out why things like infinite loops, aren't quite infinite.Other languages should also allow you to do things like this, if not messing with constants, messing with standard library functions.
They asked for harmless pranks - this would cause murders.
This is why airplanes crash
If your going that evil
#define { {}{