Check out Tie::File, it is part of the core module set. It will allow you to treat a file as an array of lines.

use Tie::File;

tie @array, 'Tie::File', filename or die ...;

# These are just like regular push, pop, unshift, shift, and splice
# Except that they modify the file in the way you would expect

push @array, new recs...;
my $r1 = pop @array;
unshift @array, new recs...;
my $r2 = shift @array;
@old_recs = splice @array, 3, 7, new recs...;

untie @array;            # all finished
[download]