Application Packaging Developer's Guide

How Classes Are Processed During Installation

The following list describes the system actions that occur when a class is installed. The actions are repeated once for each volume of a package as that volume is being installed.

  1. The pkgadd command creates a path name list.

    The pkgadd command creates a list of path names upon which the action script will operate. Each line of this list contains source and destination path names, separated by a space. The source path name indicates where the object to be installed resides on the installation volume and the destination path name indicates the location on the target system where the object should be installed. The contents of the list are restricted by the following criteria:

    • The list contains only path names belonging to the associated class.

    • If the attempt to create the package object fails, directories, named pipes, character devices, block devices, and symbolic links are included in the list with the source path name set to /dev/null. Normally they will be automatically created by the pkgadd command (if not already in existence) and given proper attributes (mode, owner, group) as defined in the pkgmap file.

    • Linked files where the file type is l are not included in the list under any circumstances. Hard links in the given class are created in item 4.

  2. If no class action script is provided for installation of a particular class, the path names in the generated list are copied from the volume to the appropriate target location.

  3. If there is a class action script, the script is executed.

    The class action script is invoked with standard input containing the list generated in item 1. If this is the last volume of the package, or there are no more objects in this class, the script is executed with the single argument of ENDOFCLASS.

    Note –

    Even if there are no regular files of this class anywhere in the package, the class action script will be called at least once with an empty list and the ENDOFCLASS argument.

  4. The pkgadd command performs a content and attribute audit and creates hard links.

    After successfully executing items 2 or 3, the pkgadd command audits both content and attribute information for the list of path names. The pkgadd command creates the links associated with the class automatically. Detected attribute inconsistencies are corrected for all path names in the generated list.