#!/usr/bin/env perl 
use strict;
use warnings;
use autodie;
use IO::Handle;

open my $fh, '+>', 'foo.txt';
print $fh "foo\nbar\nbaz\n";
$fh->flush;
seek $fh, 0, 0;
while (<$fh>) {
    print "Read: $_";
}
close $fh;