Try this 

if (   defined $cg->{'mainsnak'}
    && defined $cg->{'mainsnak'}->{'datavalue'}
    && defined $cg->{'mainsnak'}->{'datavalue'}->{'value'}
    && defined $cg->{'mainsnak'}->{'datavalue'}->{'value'}->{'notexist
+'}) {}

[download]
see http://search.cpan.org/~vpit/autovivification-0.18/lib/autovivification.pm

In reply to Re: Strange memory growth by huck
in thread Strange memory growth by spica1001

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