Numeric sorting in GNU ls

[Markus Kuhn]

Is there way to tell ls to sort filename "2" before file "10"?

In order words, can the sorting order be made to follow

/*
 * Compare two strings just like strcmp, but preserve decimal integer
 * sorting order, i.e. "2" < "10". Strings are sorted as if sequences
 * of digits were prefixed by a length indicator. Does not ignore
 * leading zeroes.
 */
int strcmpn(const char *s1, const char *s2)
{
  int digits, predigits = 0;
  const char *ss1, *ss2;

  while (1) {
    if (*s1 == 0 && *s2 == 0)
      return 0;
    digits = isdigit(*s1) && isdigit(*s2);
    if (digits && !predigits) {
      ss1 = s1;
      ss2 = s2;
      while (isdigit(*ss1) && isdigit(*ss2))
        ss1++, ss2++;
      if (!isdigit(*ss1) && isdigit(*ss2))
        return -1;
      if (isdigit(*ss1) && !isdigit(*ss2))
        return 1;
    }
    if ((unsigned char)*s1 < (unsigned char)*s2)
      return -1;
    if ((unsigned char)*s1 > (unsigned char)*s2)
      return 1;
    predigits = digits;
    s1++, s2++;
  }
}

It would be nice to be able to configure that sorting behaviour in a
command line option, as it would lead to more sensible ordering in very
many situations.

Markus

-- 
Markus G. Kuhn, Computer Laboratory, University of Cambridge, UK
Email: mkuhn at acm.org,  WWW: <http://www.cl.cam.ac.uk/~mgk25/>