###############################################################################
# SUB:          compareNumbers
# PURPOSE:      compare epoch/version/release numbers arg2 with arg1
#
# ARGS:         arg1 - first number
#               arg2 - second number
#
# NOTES:        we split the number string into an array using either
#               a dot '.' or an underscore '_'  (I haven't seen any with
#               a dash '-')
# RETURNS:      $arg2 is: -1=older than; 0=same as; 1=newer then; 2=strange
###############################################################################
sub compareNumbers {
  $arg1 = $_[0];
  $arg2 = $_[1];
  $aSize = 20;  ## arbitrary maximum number of fields in the split below
  @ver  = split /(?<=\d)(?=[a-zA-Z])|(?<=[a-zA-Z])(?=\d)|\.|_/, $arg1, $aSize;
  @nver = split /(?<=\d)(?=[a-zA-Z])|(?<=[a-zA-Z])(?=\d)|\.|_/, $arg2, $aSize;
  $n = ($#ver <= $#nver) ? $#ver : $#nver;
  $n = ($n < $aSize) ? $n : $aSize; ## number of elements for for-loop

  $ret = 2;     ## default is '2=strange'

  ## loop over version/release numbers and compare
  for( $i=0; $i <= $n; $i++ ) {
    $p = $ver[$i];
    $q = $nver[$i];
    if( POSIX::isdigit($p) && POSIX::isdigit($q) ) {
      if( ($ret = $q <=> $p) != 0 ) { ## break out if not the same
        last;
      }
    }
    else {      ## not completely numeric, so treat like strings
      ## According to the sources for rpm, we can treat these
      ## elements with alphanumeric comparisons
      if( ($ret = $q cmp $p) != 0 ) { ## break out if not the same
        last;
      }
    }
  }
  ## in case the numbers are the same so far, but one had more elements:
  if( $ret == 0 ) {
    if( $#ver != $#nver ) {
      $ret = ($#ver > $#nver) ? -1 : 1;
    }
  }

  return( $ret );
}

# COMPARES name-$arg3-$arg4 to name-$arg1-$arg2 
# RETURNS: -1=older than, 0=same as; 1=newer than; # 2=strange
# SUMMARY: name-$arg3-$arg4 is <return> name-$arg1-$arg2.
sub compareVR {
        ($verone,$relone,$vertwo,$reltwo) = @_;
        $ret = 2;
        $verstat=&compareNumbers($verone,$vertwo);
        # if both versions are not equal, our result is the result of the
        # version comparison.
        if (($verstat == 1) or ($verstat == -1)) {
                $ret = $verstat;
        };
        # if both versions are equal, our result is the result of the release
        # comparison
        if ($verstat == 0) {
                $ret=&compareNumbers($relone,$reltwo);
        };
        return( $ret );
};