printf project forat specifier '%s'

The printf() function prints the string "String Array is initialized" followed by "It work!"

void printf(char* str, ...)
{
  char* s;

  va_list vl;
  va_start(vl, str);
  for (char* ptr = str; *ptr != '\0'; ptr++)
  {
    if (*ptr == '%')
    {
      ptr++;
      s = va_arg(vl, char*);
      while (*s != '\0')
        putchar(*s++);
    }
    putchar(*ptr);
  }
  va_end(vl);
}

int main()
{
  char str[60] = "String Array is initialized";
  printf("abcd %s abcd \n", str);
  printf("It work!\n");
}