$ perl -wMstrict -n
my $line = $_ if /\bWood\b/;
chomp ($line);
print "BANG!\n" if !$line;
__END__
Hello, Wood World
Foobar

##</code><code>##

Use of uninitialized value $line in scalar chomp at - line 2, <> line 2.
BANG!

##</code><code>##

while (<$fh>) {
    chomp;
    next unless /\bWood\b/;
    ...
}