Clearing a flatfile


I'm a novice with progamming, and I need urgently a simple Perl script code to put in cron to do a clear task, this way:

I have a flat file, where there is a field which is a sequence number. Each record has this field added by one, as the records were being created. Something like this:


All I need is to clear this file, deleting records, leaving only the "n" most recent, that is, the "n" records (lets say 50) with the greatest values in this field.

Thanks a lot for this great  help.

Mario Lima./
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Hi multisites,

name the following code and launch it with "perl myfile >newfile" (myfile contains your data and newfile contains the lattest n entries with biggest numbers):

$n = 50;
  $lines{$1} = $_ if(/(\d+)$/);
foreach (sort { $b <=> $a } keys %lines)
  print $lines{$_};
  last if ++$count >= $n;


It's been a week already, got any result yet?

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