Here's a fragment showing the use of Compress::Zlib to write
a compressed file. I've stripped off all the code that doesn't
have anything to do w/ Zlib. This extract is from a script I wrote to
compress/split web server logs in real-time.
use Compress::Zlib;
my $outlog=gzopen($fn,"a");
....
$outlog->gzwrite($line."\n");
....
$outlog->gzclose();