sanju7:

You could've put your data files in code tags as well, I think it would help clarify your post a little. Also, you may want to fix your indentation so that the code is easy to read. I was going to take a look at the code, but since the indentation doesn't show the program structure, I can't really read it unless I bother to download the code and reformat it. Considering it's my day off, I'm not inclined to go the extra mile.

Anyway, a couple of notes:

1. Putting the key information in a hash will let you detect duplicate lines.
2. You can easily open multiple files and print the records to different files to split your records out.

If I notice that the node is easier to read, or if you have any questions about what I wrote, I'll be happy to revisit the node and see if there's anything more I can offer.

...roboticus

That was my lack of proper care while writing down. Reformatted indented now.

Your $csv could use a ->new ({ binary => 1, auto_diag => 1 }) to catch errors better.

Uniqueifying arrays that keep the order can be done much easier. The perlfaq's give even more solutions:

tux$ cat test.pl
#!/pro/bin/perl

use strict;
use warnings;

my @data = (1, 3, 4, 5, 3, 6, 8, 4, 9);

$" = ", ";
print "(@data)\n";

{   my %seen;
    @data = grep { !$seen{$_}++ } @data;
    }
print "(@data)\n";

tux$ perl test.pl
(1, 3, 4, 5, 3, 6, 8, 4, 9)
(1, 3, 4, 5, 6, 8, 9)
[download]

From what I could tell from your desired output, you want unique user names (keep the first one seen) as opposed to simply unique e-mail addresses, so I adjusted the grep{},%seen idea below to do that just on the stuff in front of the "@".

In the join, change ',' to ', ' to add a space after the comma if that is what you want. CSV files usually do not have leading spaces.

#!/usr/bin/perl -w
use strict;

my @emailaddr;

while (<DATA>)
{
  if (/@/)  #skip lines without email addresses
  {
     push (@emailaddr, $_) foreach /[\w@.]+/g; 
  }
}

my %seen;
@emailaddr = grep { !$seen{(split(/[@]/,$_))[0]}++}@emailaddr;

print join(',',@emailaddr),"\n";

#output line
#alay@nkk.com,brps@nkk.com,luin@nkk.com,sthn@nkk.com,toen@nkk.com,mara
+@nkk.com,wnrd@nkk.com,jpnd@ckk.com,Daim@nkk.com,nbic@ckk.com,nbrs@cra
+wford.com,nbc1@Ckk.com,jodo@nkk.com,trrt@nkk.com,alam@mkk.com,Case@nk
+k.com,miob@ikk.com,JTny@ikk.com,RBwn@ikk.com,jsab@ikk.com,Shli@nkk.co
+m,Stee@nkk.com,Eron@nkk.com

__DATA__
                                                                      
+                            argument_value                           
+                                                                     
+                                                                     
+                                  
----------------------------------------------------------------------
+---------------------------------------------------------------------
+---------------------------------------------------------------------
+---------------------------------------------------------------------
+---------------------------------------------------------------------
+---------------------------------------------------------------------
+---------------------------------------------------------------------
+-----------------------------------------------
 alay@nkk.com
 brps@nkk.com, luin@nkk.com
 sthn@nkk.com

 toen@nkk.com

 mara@nkk.com

 alay@nbkk.com
 wnrd@nkk.com, jpnd@ckk.com, Daim@nkk.com, nbic@ckk.com, nbrs@crawford
+.com, nbc1@Ckk.com,jodo@nkk.com, mara@nkk.com

 trrt@nkk.com
 alay@nkk.com
 alam@mkk.com, Case@nkk.com, miob@ikk.com, JTny@ikk.com, RBwn@ikk.com,
+ jsab@ikk.com, Shli@nkk.com, Stee@nkk.com, Eron@nkk.com
[download]

This works like a charm. Thank you for your time.