use strict;
use File::Find;

find(
    sub {
        return 1 if -d;

        my @chunks = read_file() =~ /^[^\n]*\border\b.{1,30}\bof\b[^\n]*/gims;
        return unless @chunks;

        print "$File::Find::name: @chunks\n\n"
    },
    "."
);

sub read_file {
    local $/;
    local @ARGV;
    push @ARGV, (@_ ? @_ : $_);
    <>
}