It would be nice practice if you use html parsers for parsing a html like HTML::Parser,

Same practice is also mentioned in perlfaq6 - How do I match XML, HTML, or other nasty, ugly things with a regex?

if you really want to have regex for it then try

my $str ="<title>
This is a very good site for regular Expressions.
Very helpful.
Thanks.
</title>";

#print"$str\n";

$str =~ m#<title>(.*?)</title>#gis;
my $matched_output = $1;
#print"\n$matched_output\n";
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