#!/usr/bin/perl

use strict;
use warnings;

while (<>) {
    chomp;
    $duplicates{$_}++;
}

foreach my $key (keys %duplicates) {
    if ($duplicates{$key} > 1) {
        delete $duplicates{$key};
        print "$key\n";
    }
}

[download]
Expects to be run as script < inputfile > outputfile

In reply to Re: Find duplicate lines from the file and write it into new file. by shigetsu
in thread Find duplicate lines from the file and write it into new file. by anna_here

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