I'm trying to do something I was doing in the 9th grade with no problem. And here I can't seem to make it work.

I want to alter a char * variable piece by piece. Basically I want to build up the variable at different parts of code. But leaving that aside, this is what I'm doing:

char *LEVEL="01.dat";
LEVEL[0]='0';

As simple as that. No compile errors, but the precise row < LEVEL[0]='0'> is making my program crash. And I have no idea why. I know there are alternatives and I could try using string or something, but I wouldn't want to change a ton of code to adapt to them. I mean this HAS to be doable. So what am I missing here?

Don't you want:
char LEVEL[] = "01.dat";
LEVEL[0] = '0';
?
If you do it how you are, you are trying to modify a pointer to a string literal....

The code is correct, except one thing: the string here is in read-only memory address.
The solution is to use Rubeus' code, which creates a local copy of the string.

Thank you very much. It's hard for me to understand what I'm doing wrong when there is no compilation error just a crash. Thank you very much!