I have 3 CSV files which I am using as input. They do not necessarily have identical server names nor are they necessarily in the same sort order. Also a particular input file may have more than 1 line with the same server name (see Server wsomddvfxa01 in File A. 
File A 
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 B
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 C
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

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What I am trying to do is for each Server (in Column 1) I want to get the Avg CPU (in Column 2) from each of the 3 files. In the files above this would produce 

File OUT
WSOMQAVPRA05,93.75,34.78,93.13
wsomdavpra03,90.39,69.04,68.85
wsomddvfxa01,39.22,92.44,46.97
wsompapgtw05,0,48.77,30.66

[download]

Notice in File OUT for Server Name (wsompapgtw05), since wsompapgtw05 does not appear in File A, the value is replaced with '0'. I was able to do this in my perl code (i.e., place a '0' in the output file when a particular server name appears in at least 1 of the input files, but not in all of the input files).

I have not yet been able to accomplish the 2nd desired task. Notice in File OUT the values for Server Name (wsomddvfxa01) are taken from the first line in File A. I want my perl code to pick out the Avg CPU value from the first data line when there are more than one line for a given Server Name in one of the input CSV data files.

My perl code looks as follows: 

 #!/usr/bin/perl

 use strict;
 use warnings;

 ################################################
 #
 #  Create File with Avg CPU Numbers for each Server  #  Name
 #
 ###############################################

  my %usage;
  my $files = 0;

  for my $file (”sfull1ns.dat”,”sfull2ns.dat”,”sfull3ns.dat”)  {

  open (my $fh,”<”,$file) or die “Can’t open file $file: $!”;

  while (my $line = <$fh>) {

  chomp($line);
   my ($server, @data) = (split(“,”,$line));
  
   if ($data[0] lt “!” )  {
      $data[0] = 0;
   }

   next if grep /[^0-9.]/, @data;

   $usage{$server} = [] unless exists $usage{$server};
   push @{$usage{$server}}, 0 while @{$usage{$server}}                
+ < $files;
    push @{$usage{$server}}, $data[0];
    }
    continue {
      $files++ if eof;
    }

    close $fh or die “Can’t close file $file: $!”;

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Code tags added by GrandFather

In reply to Eliminating Duplicate Lines From A CSV File by country1

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