#!/usr/bin/perl
use strict;
use warnings;
my $string = qq|cgi-programming-with-perl.zip|;
my $item = 'perl';
$string =~ s/(\s?[-\w\.]*(?$1<\/b>/gi;
print $string . "\n";
output :
book-cgi-programming-with-perl.zip
####
book-cgi-programming-with-perl.zip
##
##
/book-cgi-programming-with-perl.zip