Rename type file

#include <stdio.h>
#include <string.h>
#define N 256
/*
    Hello.txt - > Hello.xyz
*/
void renameTypeFile(char src[], char dest[], char *needle, char *text){
    int c = strcspn(src, needle);
    strncpy(dest, src, c);
    strcat(dest, text);
}

int main(int argc, char **argv)
{
    char str[] = "Hello.txt";
    char str2[N] = {'\0'};
    renameTypeFile(str, str2, ".", ".xyz");
    printf("%s", str2);
    return 0;
}