#! perl -slw
use strict;

my $word = $ARGV[0] or die "No search term";

( my $text = do{ local $/; <DATA> } ) =~ tr[\n][]d;

$text =~ s[
    ( (?: \S+ \s+ ){1,3} )
    ( $word ) [[:punct:]]*
    (?= (
        (?:
            (?: \s+ \S+ ){0,6}
            \s+ ( $word ) [[:punct:]]*
            (?: \s+ \S+ ){1,3}
        )
        |
        (?: \s+ \S+ ){1,3}
    ) )
][
    my $extract = "$1<$2>$3";
    $extract =~ s[\s($word)][ <$1>]g;
    print $extract;
]gex;

__END__
Regular expressions have always been a weak spot for me, and I've got a
 question that's got me stumped. Here's the problem I'm trying to solve.
 I have somwhat large articles of text (returned from a search), what I'd
 like to do is capture the word and X number of words before and after it
 while tagging the matching word in the captured text. My inital thought
 was to try something like this. The problem I have is that if there is
 more than one term and they overlap, the nth term will not be annotated.
 So my next thought is lookahead/lookbehind, but they don't capture.
 Is there a way to do this with a single regex? Is a regex even the best
 way to do this? Thanks, -Lee