my( $min, $max ) = ( 4, 32*1024 );
local( $/ ) = \(32*1024);
my $prev = '';
while( <> ) {
    $prev .= $_;
    while( $prev =~ /([\n\t -~]{$min,$max})\0/g ) {
        print "$1\n";
    }
    $prev =~ s/.*\0//s;
}