#!/usr/bin/perl -w 
use strict; 
use LWP::Simple; 


open ("output","> outputfile.txt") || die ("Could not open output file $!"); 

my $html = get("http://www.htmladdress.com/file.html") 
or die "Couldn't fetch the site."; 
while($html=~ m{(.+\n.+(key\sword1|key\sword2|key\sword3).+\n.+)}gim){ 
my $text =$1; 
$text =~ tr[\n][ ]; 
print output "$text\n"; 
} 

close ("output");