system('zip',$zipfile_name,'*.pdf');
## don't forget to check $? for errors

##</code><code>##

use Archive::Zip;
my $zip = new Archive::Zip;

for (glob '*.pdf') {
   my $member = $zip->addFile($_);
   $member->desiredCompressionMethod( COMPRESSION_DEFLATED );
}

die "Can't write zip file" if $zip->writeToFileNamed('pdfs.zip') != AZ_OK;