#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
use List::MoreUtils qw(uniq);

my $re = "iowq john stepy andy anne alic bert stepy anne bert andy step alic andy";
my $i = 0;
my %hash = map { ++$i => $_ } uniq split(/\s+/, $re);
print Dumper \%hash;

__END__

 perl test.pl
$VAR1 = {
          '6' => 'alic',
          '8' => 'step',
          '1' => 'iowq',
          '4' => 'andy',
          '2' => 'john',
          '7' => 'bert',
          '5' => 'anne',
          '3' => 'stepy'
        };