A Simple Script to Remove Duplicate Emails

Basic Perl Programming

Suppose you have a list of emails compiled from different sources and want to get rid of duplicates. You google this and to your amazement (and mine), there is no free service available to paste your emails to return a list of unique addresses.

Here is a small simple script to eliminate email duplicates, in case this saves a few minutes (or hours!) to someone else.

This script is written in Perl and takes a list of email addresses (one per line), prunes it and returns a list with unique ones. You will need to have installed Perl in your computer (you can download it for free in Windows using ActivePerl); any flavors of UNIX or Mac OS should have Perl installed by default.

Once you have Perl installed, copy the following script to a file and save it as duplicate_email_remover.pl in a suitable directory:

use strict;
my %hash;
while(my $line = <>) {
map {print $_ ."\n"} keys %hash;

Also make sure that you have your email list (one email per line) saved in a file named emails.txt in the same directory where you saved duplicate_email_remover.pl.

Run the following command in your console (or command prompt if you use Windows):

perl duplicate_email_remover.pl < emails.txt

You should get printed to your console a list of emails with unique addresses.



  1. rmp

    Another way :)

    “sort” is available on unix-like systems – linux, bsd, solaris etc., cygwin or mingw for Windows:

    sort -u output.txt

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