Sorry if i argued. Actually i did clicked the download but which takes me to plain text page where i can copy the code.

This is how i have done.. It doesnt work in my windows perl but now i tested in ubuntu perl. its working. The output is exactly as i m expected.

I think there may be some problem with version. Thanks for the replies..

use warnings;
use strict;

my $str1 = q/It is a guide to action which ensures that the military a
+lways obey the commands of the party./;
my $str2 = q/It is a guide to action that ensures that the military wi
+ll forever heed Party commands is a guide./;

my $n = 0;
while ( $str1 =~ /(?=(\S+\s+\S+\s+\S+))/g ) {
    my $t1 = $1;
    while ( $str2 =~ /($t1)/g ) {
        print "$1\n";
        $n++;
        }
    }

print "No of matching is : $n\n";
[download]

It is a
t is a
is a guide
is a guide
s a guide
s a guide
a guide to
guide to action
uide to action
ide to action
de to action
e to action
ensures that the
nsures that the
sures that the
ures that the
res that the
es that the
s that the
that the military
hat the military
at the military
t the military
[download]

This is what the code suggested: ...

I have downloaded the code properly.

Dear saravan,

You did not download the code properly. Like I already told you in Re^7: count the maximum no.of occurence, use the download code link to download the code

And here is the output for that:

Simply repeating what you already said is annoying, esp when other parts of what you are saying are obviously wrong.

Which perl are you using? I get the correct output using v5.12.2

perldeltas says

A pattern containing a + inside a lookahead would sometimes cause an incorrect match failure in a global match (e.g., /(?=(\S+))/g)

#68564: /g failure with zero-width patterns

Cut & paste is not the same as download. The "+" signs in your sample data exist because you didn't use the download link. Instead you used cut & paste. That would be fine, except that perlmonks wraps long code lines (to prevent lines from uglificating the page). When it does so, it includes a '+' at the beginning of wrapped lines to let you know about it.

If you use the download link, you'll get a nice plain text page that you can save, and it will be the correct code.

...roboticus

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

It is a
t is a
is a guide
is a guide
s a guide
s a guide
a guide to
guide to action
uide to action
ide to action
de to action
e to action
ensures that the
nsures that the
sures that the
ures that the
res that the
es that the
s that the
that the military
hat the military
at the military
t the military
Quantifier follows nothing in regex; marked by <-- HERE in m/(+ <-- HE
+RE lways obey the)/ at ngram1.pl line 12.
[download]

Hi, After execution only i got the output that i showed a while ago..

Like I already said this is impossible.

Also there is an error along with the output shown:

Use the correct download link to download the code. Read How does 'Select Code to Download' Work?, Understanding and Using PerlMonks, PerlMonks FAQ