Here is a recursive check, without autovivification. 
sub _exists {
    my ($hash, @keys, @exists) = @_;

    if (exists $hash->{$keys[0]}) {
        my $key = shift @keys;
        push @exists, 1, _exists($hash->{$key}, @keys);
    }

    return @exists;
}

sub exists_keys {
    return &_exists == $#_ ? 1 : ();
}

my %hash;
#$hash{a}{b}{c} = undef;

if (exists_keys(\%hash, qw(a b c))) {
    print "Exists.\n";
}
else {
    print "Doesn't exists.\n";
}

[download]

In reply to Re: Checking if hash value exists without implicitly defining it by trizen
in thread Checking if hash value exists without implicitly defining it by Doctrin

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.