http://www.perlmonks.org?node_id=660227


in reply to Remove Duplicates!! Please Help

Your solution works, except for stripping newlines (because of the chomp). If you just change the print FILE2 line to:
print FILE2 $Previous, "\n";
Then it will do what you want.

Here's an alternate command-line solution:
perl -ane 'print unless $seen{$F[0]}++' /tmp/data
See perlrun for the -ane options. Here's what it looks like in use:
[me@host me]$ cat /tmp/data COMPUTER DISTRIBUTION_ID STATUS </br> 30F-WKS `1781183799.xxxx1' IC---</br> 30F-WKS `1781183799.xxx11' IC---</br> ADM34A3F9 `1781183799.41455' IC---</br> [me@host me]$ perl -ane 'print unless $seen{$F[0]}++' /tmp/data COMPUTER DISTRIBUTION_ID STATUS </br> 30F-WKS `1781183799.xxxx1' IC---</br> ADM34A3F9 `1781183799.41455' IC---</br>