Modifying value of char pointer in c produces segfault

Question

The following code produces a segmentation fault on my system. I can\'t figure out why. Any help would be appreciated.

#include
int main() {
         


        

Answer 1

Attempting to modify a string literal causes undefined behaviour.

Answer 2

The standard explicitly lists this as undefined behavior in §J.2:

— The program attempts to modify a string literal (6.4.5)

If you want to copy it into a local array, do:

char a[] = "abc";

a is an array on the stack, and you can modify it freely.