Converting and printing array of hashes - Perl - arrays

Question

I really dont know how to do it so I ended up here.
I want to convert this input:
my #sack_files_1 = (
'mgenv/1_2_3/parent.dx_environment',
'mgenv/1_2_3/doc/types.dat',
'u5env/1_2_3/parent.dx_environment',
'u5env/1_2_3/doc/types.dat',
);
To this:
my $sack_tree_1 = {
'mgenv' => {
'1_2_3' => [ 'parent.dx_environment', 'doc/types.dat' ],
},
'u5env' => {
'1_2_3' => [ 'parent.dx_environment', 'doc/types.dat' ],
}
};

Answer 1

Something like this should do the trick:
use strict;
use warnings;
use Data::Dumper;
my #sack_files_1 = (
'mgenv/1_2_3/parent.dx_environment',
'mgenv/1_2_3/doc/types.dat',
'u5env/1_2_3/parent.dx_environment',
'u5env/1_2_3/doc/types.dat',
);
my %sack_tree_1;
foreach (#sack_files_1) {
my ( $env, $number, #everything_else ) = split('/');
push( #{ $sack_tree_1{$env}{$number} }, join( "/", #everything_else ) );
}
print Dumper \%sack_tree_1

Answer 2

This will do as you ask. It uses File::Spec::Functions to split each path into its components.
The first two elements of the hash are used directly as hash keys, relying on autovivication to create the necessary hash elements.
A simple push to an implied array reference also autovivifies the lowest-level hash element.
I have used Data::Dump to display the resulting hash. It is not part of the core Perl installation and you may need to install it, but it is much superior to Data::Dumper.
use strict;
use warnings;
use File::Spec::Functions qw/ splitdir catfile /;
my #sack_files_1 = (
'mgenv/1_2_3/parent.dx_environment',
'mgenv/1_2_3/doc/types.dat',
'u5env/1_2_3/parent.dx_environment',
'u5env/1_2_3/doc/types.dat',
);
my %paths;
for my $path (#sack_files_1) {
my ($p1, $p2, #path) = splitdir $path;
push #{ $paths{$p1}{$p2} }, catfile #path;
}
use Data::Dump;
dd \%paths;
output
{
mgenv => { "1_2_3" => ["parent.dx_environment", "doc\\types.dat"] },
u5env => { "1_2_3" => ["parent.dx_environment", "doc\\types.dat"] },
}

Answer 3

my $sack_tree_1 = {};
foreach my $data (#sack_files_1) {
my #path = split '/', $data;
my ($file,$last_part) = pop #path, pop #path; # get the file name and last part of the path
my $hash_part = $sack_tree_1;
foreach my $path (#path) { # For every element in the remaining part of the path
$hash_part->{$path} //= {}; # Make sure we have a hash ref to play with
$hash_part = $hash_part->{$path} # Move down the hash past the current path element
}
$hash_part->{$last_part} = $file; # Add the file name to the last part of the path
}
This handles all path lengths of 2 or more