I do not know what a isogram is. But maybe this is what you search. 

$_ = <>;
my %h;
$h{$_}++ for ( split // );
my $not_isog = () = grep $_ > 1, values %h;
print "$_ is ", $not_isog ? 'not ' : '', "isog\n";

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Boris

In reply to Re: testing number of occurrences in a word by borisz
in thread testing number of occurrences in a word by jsmith

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