if (!number)
if (number == 0)
ethers_keys (int number, char *key[]){  int result = 0;  int i;  if (!number)    {      fprintf (stderr, _("Enumeration not supported on %s\n"), "ethers");      return 3;    }  for (i = 0; i < number; ++i)    {      struct ether_addr *ethp, eth;      char buffer [1024], *p;      ethp = ether_aton (key[i]);      if (ethp)	{	  if (ether_ntohost (buffer, ethp))	    {	      result = 2;	      continue;	    }	  p = buffer;	}      else	{	  if (ether_hostton (key[i], &eth))	    {	      result = 2;	      continue;	    }	  p = key[i];	  ethp = &eth;	}      printf ("%s %s\n", ether_ntoa (ethp), p);    }  return result;}