You can use the command-line versions of zip or 7zip easily enough. On the off chance that this is part of a larger Perl-driven process, you have two approaches:

system('zip',$zipfile_name,'*.pdf');
## don't forget to check $? for errors
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Or, you can use something like:

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;
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This is untested, of course, but it should be basically correct.