Payload-free Packages

摘要

We've explored packages and packaging several times over the years in this column. You are almost certainly familiar with the traditional installer package: a file Apple's Installer uses to copy files and folders to the correct places in the filesystem and thereby install a piece of software. But sometimes software cannot be properly installed solely by copying files to the right place. Occasionally, existing files need to be modified, or a service needs to be stopped or started, or notified of changes. For these needs and more, Apple packages also allow for the execution of scripts or executables included as part of the package. These scripts can be run before and/or after the main part of the install - that is, the part of the install where files and folders are copied into place.