Packagelink is a Perl program originally designed to build networked filesystems for UNIX servers from a list of software packages. It has since been expanded to creating filesystems on local workstations as well. It uses a ``compare-before-copy'' method, if a file currently on the disk is just like the file in the image, there's no need to copy. Packagelink also has the ability to preprocess files, replacing certain tokens with variables defined in the Machdb. A .plprocess extension is used to denote files that need preprocessing. This is most useful in the registry file for a package where tokens such as ##DOMAIN## are replaced with the value of the DOMAIN variable defined in the Machdb database.
For example, the registry file for a network card package might contain entries like this...
"Domain"="##DOMAIN##"
"DefaultGateway"="##GATEWAY##"
"IPAddress"="##IP##"
"NameServer"="##NAMESERVER##"