=head2 How can I print out a word-frequency or line-frequency summary?

To do this, you have to parse out each word in the input stream.  We'l
+l
pretend that by word you mean chunk of alphabetics, hyphens, or
apostrophes, rather than the non-whitespace chunk idea of a word given
in the previous question:

    while (<>) {
        while ( /(\b[^\W_\d][\w'-]+\b)/g ) {   # misses "`sheep'"
            $seen{$1}++;
        }
    }
    while ( ($word, $count) = each %seen ) {
        print "$count $word\n";
    }

If you wanted to do the same thing for lines, you wouldn't need a
regular expression:

    while (<>) {
        $seen{$_}++;
    }
    while ( ($line, $count) = each %seen ) {
        print "$count $line";
    }

If you want these output in a sorted order, see L<perlfaq4>: ``How do 
+I
sort a hash (optionally by value instead of key)?''.
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