Here is the modified code to my earlier code.(Earlier also I have post
+ed the code and as per perl monk i have updated and posted here)

use strict;
use warnings;
use POSIX 

my $file_duplicate="log_duplicate_remove";
my $file_consolidated_sort="log_consolidated_sort";


    open FH_duplicate, "$file_duplicate" or die "$!"; ### input file
    open FH_sorting, ">>$file_consolidated_sort" or die "$!"; #### out
+put file
    
    my %hash = ();
    my $key;
    my $val;
    
    while(<FH_duplicate>)
    {
    chomp;
    ($key,$val)=split(/,,/);
    
    $hash{$key} .= $val;
    }
    close FH_duplicate;
    
    for $key(sort keys %hash) 
    {
    print FH_sorting "$key -> $hash{$key}";
    }
    
    close FH_sorting;
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