Hm, well, then, here's an alternate approach that does away with a subroutine. I assume the goal is to avoid loading a large file willy nilly into a Perl scalar (because read is already buffered):

• Work out the total # of bytes to read.
• Work out how many chunks of $bufsiz that would need to be read.
• Work out the remaining # of bytes
• print out a sufficient # of big chunks
• print out the last chunk

Some code (totally off the top of my head, untested, just to give the idea):

# get $start, $end

my $bufsiz = 4096;
my $total_length = $end-$start;
my $chunks = int $total_length / $bufsiz;

my $data;
if ($chunks) {
    foreach (1 ... $chunks) {
        read (FILE, $data, $bufsiz);
        print $data;
    }
}
read (FILE, $data, $total_length % $bufsiz);
print $data;
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Philosophy can be made out of anything. Or less -- Jerry A. Fodor