use strict ;
    use warnings ;
    use IO::Uncompress::Bunzip2 qw(bunzip2 $Bunzip2Error) ;
    use IO::File ;
    my $input = new IO::File "<file1.txt.bz2" or die "Cannot open 'file1.txt.bz2': $!\n" ;
    my $buffer ;
    bunzip2 $input => \$buffer or die "bunzip2 failed: $Bunzip2Error\n";