在C中重新分配内存时编译中断

I'm trying an example

我正在尝试一个例子

int main(){
    int count = 5;
    char *a = "JOSUA";
    char *c = "JANETALAE";
    char *b = NULL;
    char *d = NULL;
    b = (char *)malloc(sizeof(char)*5);
    b = a;
    if(b == NULL){
        printf("\n malloc failed");
    }
    printf("\nChar is:%s\n",b);
    d = (char *)realloc(b,sizeof(char) * 9);
    if(d == NULL){
        printf("\n realloc failed");
    }
    else{
        b = d;
        b = c;                                                                                                                                                                             
    }
    printf("\nChar is:%s\n",b);
    return 0;
}
int main()