Extract Mail Adresses from CSV

What do you think about the code below?
I have a file containing information about people, where the fifth element of the tab separated line contains the mail address.
Each mail address appears multiple times, I need to print them unique.

my %mails;
open my $csv, '<', 'my.csv' or die $!;
while (<$csv>){
    my  $mail = ( split(/\t/) )[4]; 
    $mails{$mail} = 1
say foreach sort keys %mails;

(and how do I indent code on blogs.perl.org?)
thx @Aristotle


how do I indent code on blogs.perl.org?

The way you do it in HTML – with <pre> around <code>. I fixed it for you, check your post.

Not really what you are asking, but assuming you don't want to use some standard modules (Text::CSV) and don't want to validate your email addresses and that this isn't part of a larger program, you can do this right in the shell with:

cat my.csv | cut -f 4 | sort | uniq

Just an FYI.

Your example should work fine, as long as none of your fields ever contain a tab character. If they do, then in proper CSV they will be quoted in some manner, and sorting out things like that is what modules like Text::CSV are for. But for a one-off task where you know what your data looks like, there's nothing wrong with this.

Leave a comment

About :m)

user-pic I blog about Perl.