Question

When run following code after compiling on gcc,I get segmentation fault.

#include <stdio.h>
#include <string.h>

int main(void)
{
    struct emp
    {
        char *n;
        int age;
    };

    struct emp e1={"David",23};
    struct emp e2=e1;
    strupr(e2.n);
    printf("%s\n%s\n",e1.n,e2.n);
    return(0);
}

Answer 1

String literals like "David" cannot be altered, which is what you’re doing when you call strupr. You should copy the string (e.g. with strdup) before.