As far as I can tell, there are 3 questions here.

Firstly:
From a unix-like prompt, just do head -1 infile > outfile; cat tail -n+2 infile | sort -u >> outfile
But if you must use Perl (yay):
open IN,'<',$csvfile;
@data=<IN>;
close IN;
open OUT,'>',$newfile;
print OUT shift @data;
foreach my $line (@data) {$uniq{$line}=1;}
foreach my $line (keys %uniq) {print OUT $line;}
close OUT;

[download]
Please do the usual 'strict' and 'warning's stuff.


Secondly, you talk about putting the data into some sort of structure in memory...
Here I second cavac's request for a SSCCE


Thirdly, to create deep structures, mostly Perl will 'Just do it for you'.
E.G. I can do $data{A}{B}{C}=[0,1]; $data{A}{X}=[5]; and I'll end up with the weird monstrosity I asked for:
  DB<2> x \%data
0  HASH(0x555e18bb11b8)
   'A' => HASH(0x555e184f6448)
      'B' => HASH(0x555e18bb1218)
         'C' => ARRAY(0x555e18bb1290)
            0  0
            1  1
      'X' => ARRAY(0x555e18bb1278)
         0  5
  DB<3>

[download]

HTH!

In reply to Re: Building a dynamic array or some other method? by The_Dj
in thread Building a dynamic array or some other method? by CAdood

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