It's even easier with grep. But in perl, grep wants to match against a list, so you'll be back to reading line-by-line:

#!/usr/bin/perl
use strict; use warnings

print "<$_>\n" for grep {chomp; /(fox|wood)/} <DATA>;

__DATA__
Now is the time for all good
men to come to the aid of their
party.  The quick red fox jumped
over the lazy brown dog. How much
wood can a woodchuck chuck?  If
a woodchuck could chuck wood?
[download]

This should give the same result. (Note: the chomp isn't required, but I wanted to match the output of the previous code, so I put it in.)

...roboticus

When your only tool is a hammer, all problems look like your thumb.