my (@dat) = (); my @filters; push @filters, sub { /active/ ? 1 : undef }; push @filters, sub { /anotherfilter/ ? 1 : undef }; open my $DATF, '<', $file_name; while( chomp(my $line = <$DATF>) ) { foreach my $filter (@filters) { my $newline = $filter->($line) or next; push (@dat, $line); last; } } close($DATF); #### use threads; use Thread::Queue; use constant MAXTHREADS => 2; my $workQueue = Thread::Queue->new(); my $outQueue = Thread::Queue->new(); my @threads = map { threads->new( \&worker ) } 1..MAXTHREADS; open my $DATF, '<', $file_name; while ( <$DATF> ) { $workQueue->enqueue($_); } close $DATF; $workQueue->end(); $_->join for @threads; $outQueue->end(); my @dat; while (my $line = $outQueue->dequeue()) { push @dat, $line; } sub worker { my @filters; push @filters, sub { /active/ ? 1 : undef }; push @filters, sub { /anotherfilter/ ? 1 : undef }; while ( chomp(my $line = $workQueue->dequeue()) ) { foreach my $filter (@filters) { my $newline = $filter->($line) or next; $outQueue->enqueue($line); last; } } }