Try Tie::File, here is a piece of its man page:

# This file documents Tie::File version 0.93

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

$array[13] = 'blah';     # line 13 of the file is now 'blah'
print $array[42];        # display line 42 of the file

$n_recs = @array;        # how many records are in the file?
$#array -= 2;            # chop two records off the end

for (@array) {
  s/PERL/Perl/g;         # Replace PERL with Perl everywhere in the fi
+le
}

# 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 $r1 = shift @array;
@old_recs = splice @array, 3, 7, new recs...;

untie @array;            # all finished
[download]

Hope this helps, Valerio