Modifying a char array inside a function in C [duplicate]

Answer 1

In short, is there any way I can take in a char *input into a function and modify its original memory address without using something like memcpy from string.h?

Yes, you can. Your function modifyCharArray is doing the right thing. What you are seeing is caused by that fact that

char *test = "Bad";

creates "Bad" in read only memory of the program and test points to that memory. Changing it is cause for undefined behavior.

If you want to create a modifiable string, use:

char test[] = "Bad";