my $FILE = "joe.txt";

    open FH, $FILE or die "Can't open $FILE: $!";
    my %hash;
    while (<FH>) {
        chomp;
        my($key, $val) = split /=>/;
        $hash{$key} = $val;
    }
    close FH or die "Can't close $FILE: $!";

    $myhash{$timestamp}=$newLine;

    open FH, ">" . $FILE or die "Can't open $FILE: $!";
    print FH join("\n", map $_ . "=>" . $hash{$_}, keys %hash), "\n";
    close FH or die "Can't close $FILE: $!";