#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

sub change_all_elements {
    my ( $data, $subref ) = @_;
    if ( ref($data) eq 'HASH' ) {
        for my $k ( keys %$data ) {
            change_all_elements( $data->{$k}, $subref );
        }
    }
    elsif ( ref($data) eq 'ARRAY' ) {
        for my $line (@$data) {
            change_all_elements( $line, $subref );
        }
    }
    elsif ( ref($data) eq '' ) {
        $subref->($data);

    }
    else {
        die "I dont know " . ref($data) . "\n";
    }
}

my $deep = {
    a => 12,
    b => 13,
    c => {
        d => 14,
        e => 15,
    },
    f => [ 16, 17, ]
};

# I want to have all scalar elements to be 100x
my $changed = change_all_elements(
    $deep,
    sub {
        100 * $_[0];

    }
);
print "All changed:\n";
print Dumper($deep);