What code have you written so far?

This is a faq, see perlfaq4 on "duplicate".

Alternatively, see Algorithm::Diff.

Maybe you want to tell us in more detail what makes the last five lines special.

i tried with this but i'm not getting the required output

#!/usr/bin/perl
open (FILE,"file1");
@cnt_file = <FILE>;
$cnt = @cnt_file;
print "$cnt\n";
open (MYFILE,"file2");
$line = <MYFILE>;

foreach $line (<MYFILE>) {
print "$line" if $. >= $cnt;
}
[download]

varalaxmibbnl:

When you have a problem like this, you should add some print statements to show your variables, so you can verify that they hold what you're expecting. In this case, try adding $. to your existing print statement, like this:

print "$., $line"
[download]

When you do so, your output is:

10
15: 1
15: hw
15: r
15: u
15: hi
15: 2
15: hw
15: r
15: u
15: hi
15: 3
15: hw
15: r
15: u
[download]

So you can see that the line number is 15 for every iteration through your for loop. Why is that? It turns out that when you use foreach it wants a list in the parenthesis, so it reads the entire file at once. It then gives you one line at a time.

Generally when processing a file and want to do it one line at a time, we do it like:

while (my $line = <MYFILE>) {
   ... code in loop ...
}
[download]

There are some other issues in your code, but I'll let your instructor clarify that.

...roboticus

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

What do you think this code actually does? Please stop and think about that for a minute. Some hints:

• use strict; use warnings; Use strict and warnings (then fix the errors), Basic debugging checklist
• use open properly
• http://learn.perl.org, Tutorials, Modern Perl.

Hi varalaxmibbnl,
Several good advice has been given, however comparing the content of the files you presented in your original post.
I can see that file1 is contained in file2 in such a way that if the two files are saved in different arrays, one can use splice to get the difference of the files like:

use warnings;
use strict;
use Inline::Files;

my @file1 = <DATA1>; # updated

my @file2 = <DATA2>; # updated

print $_ for splice @file2, $#file1 - 1, $#file2;

__DATA1__
hi
1
hw
r 
u
hi
2
hw
r
u


__DATA2__
hi
1
hw
r
u
hi
2
hw
r
u
hi
3
hw
r
u
[download]

If you remove the chomp statements, you can also remove "$_, $/ for" from the print statement.

Yes Oooo, o yes, but don't you think one is cryptic enough with the given code already, than adding some more?
I think it would be better to play clean a bit some of the time.
Remove the newline character using the chomp and then re-insert when printing finally.

hdb, on a second thought, you are right. chomp here is really not useful.
Thanks, am updating my previous post.

If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me

While not a bad solution (I gave it an upvote), here's a couple of points to consider:

• You've added two blank lines between the __DATA1__ and __DATA2__ blocks. As a result, you've needed the "$#file1 - 1" calculation.
• I think using splice here is overkill: a simple array slice would suffice.

Putting those two points into effect:

#!/usr/bin/env perl

use strict;
use warnings;

use Inline::Files;

my @file1 = <DATA1>;
my @file2 = <DATA2>;

print for @file2[@file1 .. $#file2];

__DATA1__
hi
1
hw
r 
u
hi
2
hw
r
u
__DATA2__
hi
1
hw
r
u
hi
2
hw
r
u
hi
3
hw
r
u
[download]

Output:

hi
3
hw
r
u
[download]

-- Ken

What have you tried? What part are you having problems with? A Super Search, search engine would find you lots of examples of how to do this.