As others have said, the test you're doing now only tells you whether the two arrays are the same length. While not sufficient, it is certainly a good test to do, since if the two arrays are different lengths, they can't possibly be "equal". So in your array-comparing subroutine, that's the first thing you should do.

  # pass it two arrays, by reference.
  sub arrays_equal
  {
    my( $ar1, $ar2 ) = @_;
    @$ar1 eq @$ar2 or return 0; # different lengths.
    # now do member-wise comparison:
    for my $i ( 0 .. $#{$ar1} )
    {
      $ar1->[$i] eq $ar2->[$i] or return 0; # short circuit
    }
    return 1; # all members compared equal.
  }

  # call it like so:
  if ( ! arrays_equal( \@savedpids, \@livepids ) )
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Note that I used string equality. If the arrays are going to contain only numbers, then you'd want to use numeric comparison (==) instead.

As an added syntactic nicety, you can write this subroutine with a prototype, so you don't have to pass the arrays explicitly as references:

  sub arrays_equal(\@\@)
  {
     # everything else is the same
  }

  # then you can call it like so:
  if ( ! arrays_equal( @savedpids, @livepids ) )
[download]

If you use the prototype, however, the declaration of the sub must come before the point of first use.

jdporter
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