Hi jnarayan81,

you can adapt the following code, seen on the web as "Rolling buffer" (by Toby Inkster or Ingy döt Net, can't remember):
For $n=2, on each iteration, $cache[0] and $cache[1] will contain a pair of adjacent lines.

#!/usr/bin/perl

## Go through a stream and prints all but the last n lines where n is 
+a command line argument:

my @cache;
my $n = shift @ARGV;

while(<>) {
    push @cache, $_;
    print shift @cache if @cache > $n;
}
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