result = sysconf (_SC_OPEN_MAX);
result = __sysconf (_SC_OPEN_MAX);
__ulimit (int cmd, ...){  struct rlimit limit;  va_list va;  long int result = -1;  va_start (va, cmd);  switch (cmd)    {    case UL_GETFSIZE:      /* Get limit on file size.  */      if (getrlimit (RLIMIT_FSIZE, &limit) == 0)	/* Convert from bytes to 512 byte units.  */	result =  limit.rlim_cur / 512;      break;    case UL_SETFSIZE:      /* Set limit on file size.  */      {	long int newlimit = va_arg (va, long int);	limit.rlim_cur = newlimit * 512;	limit.rlim_max = newlimit * 512;	result = setrlimit (RLIMIT_FSIZE, &limit);      }      break;    case __UL_GETOPENMAX:      result = sysconf (_SC_OPEN_MAX);      break;    default:      __set_errno (EINVAL);    }  va_end (va);  return result;}