Duplicate lines in a text file

[kummetha]

How to print the duplicates in a text file. Also the line number where the duplicate text has been found needs to be printed. pls help

KZ

[msvinaykumar]

Hi,

If you are working in Unix then, Use following command

<code>
cat -n file-name > file_name2
</code>

Then use
<code>
sort -u -k 2,4 file_name2
</code>

[kummetha]

No, I am not working in Unix. I am working with Windows.
KZ

[msvinaykumar]

Or use Uniq command

<code>
$ cat happybirthday.txt

Happy Birthday to You!

Happy Birthday to You!

Happy Birthday Dear vinay!

Happy Birthday to You!
</code>

<code>
$ sort happybirthday.txt | uniq -dc
3 Happy Birthday to You!
</code>

[KevinADC]

How to print the duplicates in a text file. Also the line number where the duplicate text has been found needs to be printed. pls help

KZ

What have you tried? Where are you stuck?

[kummetha]

many a thanks msvinaykumar, i am looking for a perl script that works with windows.
KZ

[Prakash_8111]

open(FILE,"1.txt") || die "$!";  ## 1.txt is a file name 
%seen =();
$line=0 ;
while (<FILE>)
{
        $seen{$_}++;
        $line++;
        print "$line : $_"  if $seen{$_} > 1 ;
}

[kummetha]

thanks prakash, it did really work.
also if you could provide help for a script that reads a blank line in a txt file and prints the line above the blank line.
Eg
abcdef

william
marc
sumeet

nair

output:
abcdef
sumeet
thanks in advance

[KevinADC]

At some point you should start doing your own school work and the rest of the people participating in this thread you stop doing it for you.