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hash - Dynamically/recursively building hashes in Perl?

I'm quite new to Perl and I'm trying to build a hash recursively and getting nowhere. I tried searching for tutorials to dynamically build hashes, but all I could find were introductory articles about hashes. I would be grateful if you point me towards the right direction or suggest a nice article/tutorial.

I'm trying to read from a file which has paths in the form of

one/two/three
four
five/six/seven/eight

and I want to build a hash like

VAR = {
    one : {
        two : {
            three : ""
        }
    }
    four : ""
    five : {
        six : {
            seven : {
                 eight : ""
            }
        }
    }
}

The script I'm using currently is :

my $finalhash = {}; 
my @input = <>;

sub constructHash {
    my ($hashrf, $line) = @_; 
    @elements = split(///, $line);
    if(@elements > 1) {
        $hashrf->{shift @elements} = constructHash($hashrf->{$elements[0]}, @elements ); 
    } else {
        $hashrf->{shift @elements} = ""; 
    }
    return $hashrf;
}

foreach $lines (@input) {
    $finalhash = constructHash($finalhash, $lines);
}
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1 Answer

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by (71.8m points)

Data::Diver covers this niche so well that people shouldn't reinvent the wheel.

use strict;
use warnings;
use Data::Diver 'DiveVal';
use Data::Dumper;

my $root = {};
while ( my $line = <DATA> ) {
    chomp($line);
    DiveVal( $root, split m!/!, $line ) = '';
}
print Dumper $root;
__DATA__
one/two/three
four
five/six/seven/eight

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