When you call the sub like this my $alldata= get_data(); you aren't passing anything to the subroutine. There is no data for it to get.

When you do this $one_num = $infs->{ $one_num }, where was the value for $one_num initialized? It doesn't look like it was initialized to anything so the value inside the brackets is going to be undef. Are you using warnings? Strict?

my $c = -1;
...
foreach my $infs (@{ $data->{ info } }) {
    $c++;
    ...
    push @{ $AoA[$c] },
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A more Perlish way to do this is to push each value into a temporary array inside the loop and then push that array into @AoA at the end of each itteration. This would drop out all the loop variables and simplify the notation.