Archive::Zip wasn't adding any files because you didn't give it any. 22 bytes is the size of an empty zip file.

Here's demo code: create empty file and see that it's 22 bytes.

use Archive::Zip qw( :ERROR_CODES :CONSTANTS );
my $zip = Archive::Zip->new();
unless ( $zip->writeToFileNamed("someZip1.zip") == AZ_OK ) {
    die "write error: $!";
}
[download]

Same code, but add one file named "perl150.pl".

use Archive::Zip qw( :ERROR_CODES :CONSTANTS );
my $zip = Archive::Zip->new();
my $file_member = $zip->addFile( "perl150.pl" );
unless ( $zip->writeToFileNamed("someZip2.zip") == AZ_OK ) {
    die "write error: $!";
}
[download]

And the output files:

$ ls -l someZip*
-rw-r--r-- 1 gmargo gmargo  22 Oct 28 10:39 someZip1.zip
-rw-r--r-- 1 gmargo gmargo 335 Oct 28 10:34 someZip2.zip
$ unzip -v someZip1.zip 
Archive:  someZip1.zip
warning [someZip1.zip]:  zipfile is empty
$ unzip -v someZip2.zip 
Archive:  someZip2.zip
 Length   Method    Size  Ratio   Date   Time   CRC-32    Name
--------  ------  ------- -----   ----   ----   ------    ----
     282  Defl:N      217  23%  10-28-09 10:34  ade4be0c  perl150.pl
--------          -------  ---                            -------
     282              217  23%                            1 file
[download]