use strict;
use warnings;

use experimental 'smartmatch';
use Data::Dump 'dump';

my @ipaddresses = ('');

my $targetfile="/etc/hosts";

my $ipentry="";
#my @domains = ('');

my @domains;
my %hashEntries;


open(my $descripteur,'<:encoding(UTF-8)', $targetfile) or die "$target
+file not found :{";

while(my $ligne = <$descripteur>)             # tant que nous ne somme
+s pas arrivés à la fin du fichier
{
    chomp $ligne;                                                    #
+ on enlève le caractère '\n' de fin de ligne
    
    if($ligne =~ /^([0-9]{1,3}\.){3}[0-9]{1,3}/)
    {
        ($ipentry,@domains)=split('\s{1,}|\t',$ligne);                
+                    # on "splitte" à un ou plusieurs espaces ou à une
+ tabulation
        
        if(!($ipentry ~~ @ipaddresses))
        {
            print "IP trouvée --> $ipentry \n";
            $hashEntries{$ipentry} = [ "@domains" ];
            push(@ipaddresses,$ipentry);
        }
        else
        {
            my @temp=$hashEntries{$ipentry};
            print "[Add] Nombre d'éléments: @temp\n";
            push(@temp,[@domains]);
            
            $hashEntries{$ipentry} = [@temp];                         
+                                   # contre intuitif... un "add" ou "
++=" ou quelque chose qui pourrait noter qu'on ajoute à ce qui existe 
+déjà...
            print "[After] Nombre d'éléments: @temp\n";
            
        }
    }
}

print dump(%hashEntries)."\n";

foreach my $key (keys %hashEntries)
{
    my @temp=$hashEntries{$key};
    
    #print "Elements: ".@temp."\t";
    
    print "[After no dump] Test 2 $key ->\t";
    foreach my $element (@temp)
    {    
        if($element ~~ /ARRAY/)
        {
            print "Array détecté...\t";
            foreach my $autreelement (@$element)
            {
                    print "[@$autreelement]\n";
            }
        }
        print "[@$element]\n";
    }
}

close($descripteur);

[download]
The issue is related to the fact that when I try to print out the content of the hash I got strange behaviour... it displays the datas in the hash plus the references (pointers) to something I consider as already processed...

After no dump Test 2 127.0.0.6 -> Array détecté... www.examendecembre.uaa12.test <-- HORRAY I can do stuff on it
test.com test2.com test3.com <-- HORRAY I can do stuff on it
ARRAY(0x560b271bdff0) ARRAY(0x560b271e18f8) <-- ???????????????????????????

The meaning of this script is to edit the /etc/hosts in order to let, for each IPv4 address, only one line with all domain names related to this IP instead of having a real mess in /etc/hosts.
For example:
127.0.0.3 onehost
...
127.0.0.6 onehost
...
127.0.0.5 oneotherhost
...
127.0.0.6 manyotherhosts host1 host2 host3
Would become...
127.0.0.6 onehost manyotherhosts host1 host2 host3
...once this script was launched.

Questions: how to

  1. Detect the element is an ARRAY... in perl
  2. Acknowledge the number of elements in each hash
  3. Avoid having the two ARRAY references within a hash element

In reply to [Perl 5.26][Linux LEAP] Array/List/Hash misunderstanding by soundlord

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