As an aside, that's a fairly poor regex to capture "words". It will have trouble with contractions, hyphenated words and words which contain characters not in the current locale. It may be good enough for what you are doing, but you might want to consider using something a little more robust.

Still not perfect, but covering a lot more cases:

use warnings;
use strict;

while ( my $line = <DATA> ) {
    while ( $line =~ /(\p{Alnum}+([-']\p{Alnum}+)*)/g ) {
        my $word = $1;
        print "$word\n";
        # blah
    }
}

__DATA__
Tom's wouldn't, they're McCain-Feigngold maņana.
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