use warnings;
use strict;

my %data;
while (<DATA>) {
    my @cols = split;
    push @{ $data{first} }, $cols[0];
    push @{ $data{last } }, $cols[1];
    push @{ $data{phone} }, $cols[2];
    push @{ $data{email} }, $cols[3];
}

for my $item (qw(first last phone email)) {
    print "$item\n";
    print "$_\n" for @{ $data{$item} };
    print "\n";
}

__DATA__
John Smith 1234 lala@lala.com
Peter Jones 6789 ttt@yahoo.com
George Lukas 9086 lll@hotmail.com
[download]

prints out:

first
John
Peter
George

last
Smith
Jones
Lukas

phone
1234
6789
9086

email
lala@lala.com
ttt@yahoo.com
lll@hotmail.com
[download]

• perldsc