#!/usr/bin/perl -l

use strict;
use warnings;

use Data::Dumper qw(Dumper);

{
    my $boundary = 2;
    my $keyword = 'hallo';

    my %table = map { $_ => join ' ', ($keyword, 'foo') x $_ } (0, 1, 2, 3, 4);

    my $does_match = sub {
        my ($str) = @_;

        my $occurences = 0;
        $occurences++ while $str =~ /(?:\A|\b)$keyword(?:\b|\z)/g;

        return { occurences => $occurences, match => ($occurences >= $boundary) ? 'yes' : 'no' };
    };

    print Dumper \%table;

    foreach my $often (sort { $a <=> $b } keys %table) {
        my $retval = $does_match->($table{$often});
        print "occurences: $retval->{occurences}, match: $retval->{match}";
    }
}

$VAR1 = {
          '4' => 'hallo foo hallo foo hallo foo hallo foo',
          '1' => 'hallo foo',
          '3' => 'hallo foo hallo foo hallo foo',
          '0' => '',
          '2' => 'hallo foo hallo foo'
        };

occurences: 0, match: no
occurences: 1, match: no
occurences: 2, match: yes
occurences: 3, match: yes
occurences: 4, match: yes