Is this what you want?

use strict;
use warnings;

[download]
open OUT, '>', 'sfull1ns.dat';
print OUT <<'FILE';
Server,Avg CPU,P95 CPU,Avg Mem Util,P95 Mem Util
WSOMQAVPRA05,93.75,95.87,66.67,68.13
wsomdavpra03,90.39,94,65.77,68.51
wsomddvfxa01,39.22,92.19,82.59,88.25
wsomddvfxa01,35.45,89.23,79.89,83.24
FILE
close OUT;

open OUT, '>', 'sfull2ns.dat';
print OUT <<'FILE';
Server,Avg CPU,P95 CPU,Avg Mem Util,P95 Mem Util
WSOMQAVPRA05,34.78,100,55.1,67.6
wsomdavpra03,69.04,98.55,84.07,89.73
wsomddvfxa01,92.44,97.54,67.72,71.69
wsompapgtw05,48.77,96.9,92.1,93.55
FILE
close OUT;

open OUT, '>', 'sfull3ns.dat';
print OUT <<'FILE';
Server,Avg CPU,P95 CPU,Avg Mem Util,P95 Mem Util
WSOMQAVPRA05,93.13,98.11,68.95,73.47
wsomdavpra03,68.85,97.56,76.35,98.23
wsomddvfxa01,46.97,96.29,88.23,94.02
wsompapgtw05,30.66,93.74,39.89,71.35
FILE
close OUT;

[download]
my %usage;
my @files = qw(sfull1ns.dat sfull2ns.dat sfull3ns.dat);

for my $file ( @files ) {

    open( my $fh, "<", $file ) or die "Can't open file $file: $!";

    <$fh>; # Skip header line
    
    while ( my $line = <$fh> ) {
        chomp($line);

        my ( $server, @data ) = ( split( ",", $line ) );

        $usage{$server}{$file}{value} ||= $data[0];
    }
}

for my $file (@files) {
    $usage{$_}{$file}{value} ||= 0 for keys %usage;
}

for my $server (sort keys %usage) {
    print "$server,",
        join (',', map {$usage{$server}{$_}{value}} sort keys %{$usage
+{$server}}),
        "\n";
}

[download]
DWIM is Perl's answer to Gödel

In reply to Re^3: Eliminating Duplicate Lines From A CSV File by GrandFather
in thread Eliminating Duplicate Lines From A CSV File by country1

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.