my $i = index $block, "\n";
while($i > 0){

    push @lines, substr($block,0,$i);
    substr($block,0,$i+1,'');
    $i = index $block, "\n";

}

##</code><code>##

my $block;
local $_ = '';
my $i;
while(my $n = read $fh, $block, 8192 ) {

    $_ .= $block;

    while((my $i = index $_, "\n") >= 0){
        push @lines, substr($_, 0, $i);
        substr($_, 0, $i+1, '');
    }
}
push @lines, $_ if length;