I'm also not certain what you need, but here's what I pulled together from your description.

#!/usr/bin/perl

use strict;
use warnings;

#  2022-0108: Read a CSV line w/ three elements, building a hash using
#  the third element and populated with the second element.

use Data::Dumper;

{
    my %hash;

    while (<DATA>) {

        s/\s+$//;
        my @w = split(/,/);
        push ( @{ $hash{ $w[2] } }, $w[1] );
    }

    print Dumper ( \%hash );
}

__DATA__
702005010554291,5016554291,7020000023F22
702005010524898,5016524898,70200000441E0
702005010660208,5016660208,7020000033FD0
702005010509777,5016509777,7020000033FF0
702005010633781,5016633781,7020000024092
702005010616472,5016616472,7020000043FE2
310005010601516,5016601516,7020000044201
702005010526097,5016526097,7020000013EB1
702005010681238,5016681238,7020000044052
702005010551103,5016551103,7020000023F12
702005010625010,5016625010,7020000023F51

[download]
This produces the following results: 
$VAR1 = {
          '7020000023F51' => [
                               '5016625010'
                             ],
          '7020000044052' => [
                               '5016681238'
                             ],
          '7020000033FD0' => [
                               '5016660208'
                             ],
          '7020000044201' => [
                               '5016601516'
                             ],
          '7020000023F22' => [
                               '5016554291'
                             ],
          '7020000043FE2' => [
                               '5016616472'
                             ],
          '7020000024092' => [
                               '5016633781'
                             ],
          '7020000013EB1' => [
                               '5016526097'
                             ],
          '7020000023F12' => [
                               '5016551103'
                             ],
          '7020000033FF0' => [
                               '5016509777'
                             ],
          '70200000441E0' => [
                               '5016524898'
                             ]
        };

[download]

Let us know if this is what you wanted.

Alex / talexb / Toronto

Thanks PJ. We owe you so much. Groklaw -- RIP -- 2003 to 2013.

In reply to Re: Parse file and creating hashes by talexb
in thread Parse file and creating hashes by PerlMonger79

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