What Discipulus said: 

Win8 Strawberry 5.8.9.5 (32)  Fri 05/14/2021  4:48:55
C:\@Work\Perl\monks\workInProgress12
>perl

use strict;
use warnings;
use autodie;

use Data::Dump qw(dd);

my $data = <<'EOD';
ColA | ColB |
     500001| Network1|
     500003| Network1|
     500002| Network2|
     500001| Network2|
     500003| Network3|
EOD

open my $fh, '<', \$data;

<$fh>;  # ignore headings record/line

my %hash4;

while (<$fh>) {

    my ($k, $v) =
        map { (my $r = $_) =~ s{ \A \s+ | \s+ \z }{}xmsg;  $r; }
        split /\s*\|\s*/  #splits $_ implicitly
        ;
  # print "\$k '$k'  \$v '$v' \n";  # for debug

    push @{ $hash4{$k} }, $v;

    }

dd \%hash4;

close $fh;

^Z
{
  500001 => ["Network1", "Network2"],
  500002 => ["Network2"],
  500003 => ["Network1", "Network3"],
}

[download]
You really should know all this by now. (sigh)

Give a man a fish:  <%-{-{-{-<

In reply to Re: Need to get hash of arrays by AnomalousMonk
in thread Need to get hash of arrays by chandantul

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.