#include <cstdlib>
#include <iostream>

int main()
{
  unsigned long i;
  const char *s = "   123.4567abcdefgh";
  std::cout << s << '\n';

  char *ende;
  i = std::strtoul(s, &ende, 10);

  std::cout.width(1+ (ende-s));
  std::cout << "^" << " bis hier gelesene Zahl: " << i << '\n';
}