You are modifying argv1 and filename points to it. You could try making a new string with malloc and sprintf -ing the required value into it.
This is not good, and is the cause of your problem.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.