howzabout: 
#!/usr/bin/perl -w
use strict;

my @para = qw|this is my paragraph. this is not all that interesting. 
+hey ho|;
my %hash = ();
print "non-unique words: \n";
## the interesting bit ##
map {$hash{$_}++} @para;
for (keys %hash){print "$_ " if($hash{$_}>1)};
#########################
print "\n";

[download]
gives: 
$ perl tmp.pl
non-unique words:
is, this,
$

[download]
--
charlieharvey.org.uk

In reply to Re: Finding duplicate words in a paragraph by ciderpunx
in thread Finding duplicate words in a paragraph by perladdict

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