Perhaps this works: 
$file = 'test_predictions_1';
open (FH, "<EXAMPLE");
while (<FH>) {

    chop;  # remove trailing newline

    $id = $_;
    if (exists $data{$file}{$id}) {print "match\n";}
}

[download]

<update>

Having a second look at your code: 

    if (exists $data{$file}{$id}) {print "match\n";}

[download]

Does the key $file to the hash $data even exist in the hash?

You could use Data::Dumper to dump your HoH and check if it's what you expect.

</update>

--shmem 

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

In reply to Re: hash of hashes by shmem
in thread hash of hashes by Anonymous Monk

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