Chapter 3 Enhancing the Functionality of a Package

This chapter describes how to create optional information files and installation scripts for a package. While Chapter 2, Building a Package discussed the minimum requirements for making a package, this chapter discusses additional functionality that you can build into a package, based on the criteria you considered when planning how to design your package (for more information, see Things to Think About Before Building a Package).

This is a list of the overview information in this chapter.

• Creating Information Files and Installation Scripts Task Map

• Creating Information Files

• Creating Installation Scripts

Creating Information Files and Installation Scripts Task Map

The table below lists and describes the optional features you can build into a package.

Creating Information Files

This section discusses optional package information files. With these files you can define package dependencies, provide a copyright message, and reserve additional space on a target system.

Defining Package Dependencies

You need to determine whether your package has dependencies on other packages and if any other packages depend on yours. Package dependencies and incompatibilities can be defined with two of the optional package information files, compver and depend. Delivering a compver file lets you name previous versions of your package that are compatible with the one being installed. Delivering a depend file lets you define three types of dependencies associated with your package. These dependency types are:

• A prerequisite package – meaning your package depends on the existence of another package

• A reverse dependency – meaning another package depends on the existence of your package

  ---

  Note –

  Use the reverse dependency type only when a package that cannot deliver a depend file relies on your package.

  ---

• An incompatible package – meaning your package is incompatible with the named package

The depend file resolves only very basic dependencies. If your package depends upon a specific file or its contents or behavior, the depend file does not supply adequate precision. In this case, a request script or the checkinstall script should be used for detailed dependency checking. The checkinstall script is also the only script capable of cleanly halting the package installation process.

Be certain that your depend and compver files have entries in the prototype file. The file type should be i (for package information file).

Refer to depend(4) and compver(4) for more information.

How to Define Package Dependencies

1. Make the directory containing your information files the current working directory.

2. If previous versions of your package exist and you need to specify that your new package is compatible with them, create a file named compver with your favorite text editor.

   List the versions with which your package is compatible, using this format:

   string string . . .

   string

   Is identical to the value assigned to the VERSION parameter in the pkginfo file, for each compatible package.

3. Save your changes and quit the editor.

4. If your package depends on the existence of other packages, other packages depend on the existence of your package, or your package is incompatible with another package, create a file named depend with your favorite text editor.

   Add an entry for each dependency, using this format:

   type pkg-abbrev pkg-name (arch) version (arch) version . . .

   type	Defines the dependency type. Must be one of the following characters: P (prerequisite package), I (incompatible package), or R (reverse dependency).
   pkg-abbrev	Specifies the package abbreviation, such as SUNWcadap.
   pkg-name	Specifies the full package name, such as Chip designers need CAD application software to design abc chips. Runs only on xyz hardware and is installed in the usr partition.
   (arch)	Optional. Specifies the type of hardware on which the package runs. For example, sparc or x86. If you specify an architecture, you must use the parentheses as delimiters.
   version	Optional. Specifies the value assigned to the VERSION parameter in the pkginfo file.

   For more information, see depend(4).

5. Save your changes and quit the editor.

6. Complete one of the following tasks:

   • If you want to create additional information files and installation scripts, skip to the next task, How to Write a Copyright Message.

   • If you have not created your prototype file, complete the procedure How to Create a prototype File Using the pkgproto Command, and skip to Step 7.

   • If you have already created your prototype file, edit it and add an entry for each file you just created.

7. Build your package.

   See How to Build a Package, if needed.

Where to Go Next

After you build the package, install it to confirm that it installs correctly and verify its integrity. Chapter 4, Verifying and Transferring a Package explains how to do this and provides step-by-step instructions on how to transfer your verified package to a distribution medium.

Example—compver File

In this example, there are four versions of a package: 1.0, 1.1, 2.0, and the new package, 3.0, which is compatible with all the three previous versions. The compver file for the newest version might look like:

release 3.0
release 2.0
version 1.1
1.0

The entries do not have to be in sequential order. However, they should exactly match the definition of the VERSION parameter in each package's pkginfo file. In this example, the package designers used different formats in the first three versions.

Example—depend File

This example assumes that the sample package, SUNWcadap, requires that the SUNWcsr and SUNWcsu packages already be installed on a target system. The depend file for SUNWcadap looks like:

P SUNWcsr Core Solaris, (Root)
P SUNWcsu Core Solaris, (Usr)

Writing a Copyright Message

You need to decide whether your package should display a copyright message while it is being installed. If so, create the copyright file.

You should include a copyright file to provide legal protection for your software application. It might be a good idea to check with the legal department of your company for the exact wording of the message.

To deliver a copyright message, you must create a file named copyright. During installation, the message is displayed exactly as it appears in the file (with no formatting). See copyright(4) for more information.

Be certain that your copyright file has an entry in the prototype file. Its file type should be i (for package information file).

How to Write a Copyright Message

1. Make the directory containing your information files the current working directory.

2. Create a file named copyright with your favorite text editor.

   Enter the text of the copyright message exactly as you want it to appear as your package is installed.

3. Save your changes and quit the editor.

4. Complete one of the following tasks.

   • If you want to create additional information files and installation scripts, skip to the next task, How to Reserve Additional Space on a Target System.

   • If you have not created your prototype file, complete the procedure How to Create a prototype File Using the pkgproto Command, and skip to Step 5.

   • If you have already created your prototype file, edit it and add an entry for the information file you just created.

5. Build your package.

   See How to Build a Package, if needed.

Where to Go Next

After you build the package, install it to confirm that it installs correctly and verify its integrity. Chapter 4, Verifying and Transferring a Package explains how to do this and provides step-by-step instructions on how to transfer your verified package to a distribution medium.

Example—copyright File

For example, a partial copyright message might look like:

Copyright (c) 1999 Company Name
All Rights Reserved
 
This product is protected by copyright and distributed under
licenses restricting copying, distribution and decompilation.

Reserving Additional Space on a Target System

You need to determine whether your package needs additional disk space on the target system (space in addition to that required by the package objects). If so, create the space information file. This is different than creating empty files and directories at installation time as discussed in Defining Additional Objects to Be Created at Install Time.

While the pkgadd command ensures that there is enough disk space to install your package based on the object definitions in the pkgmap file, a package may require additional disk space beyond that needed by the objects defined in the pkgmap file. For example, your package might create a file after installation, which may contain a database, log files, or some other growing file that consumes disk space. To be sure that there is space set aside for it, you should include a space file specifying the disk space requirements. The pkgadd command checks for the additional space specified in a space file. Refer to space(4) for more information.

Be certain that your space file has an entry in the prototype file. Its file type should be i (for package information file).

How to Reserve Additional Space on a Target System

1. Make the directory containing your information files the current working directory.

2. Create a file named space with your favorite text editor.

   Enter any additional disk space requirements needed by your package, using this format:

   pathname blocks inodes

   pathname	Specifies a directory name, which may or may not be the mount point for a file system.
   blocks	Specifies the number of 512-byte blocks that you want reserved.
   inodes	Specifies the number of required inodes.

   For more information, see space(4).

3. Save your changes and quit the editor.

4. Complete one of the following tasks.

   • If you want to create installation scripts, skip to the next task, How to Write a request Script.

   • If you have not created your prototype file, complete the procedure in How to Create a prototype File Using the pkgproto Command, and skip to Step 5.

   • If you have already created your prototype file, edit it and add an entry for the information file you just created.

5. Build your package.

   See How to Build a Package, if needed.

Where to Go Next

After you build the package, install it to confirm that it installs correctly and verify its integrity. Chapter 4, Verifying and Transferring a Package explains how to do this and provides step-by-step instructions on how to transfer your verified package to a distribution medium.

Example—space File

This example space file specifies that 1000 512-byte blocks and 1 inode be set aside in /opt on the target system.

/opt   1000   1

Creating Installation Scripts

This section discusses optional package installation scripts. The pkgadd command automatically performs all the actions necessary to install a package using the package information files as input. You do not have to supply any package installation scripts. However, if you want to create customized installation procedures for your package, you can do so with installation scripts. Installation scripts:

• Must be executable by the Bourne shell (sh).

• Must contain Bourne shell commands and text.

• Do not need to contain the #!/bin/sh shell identifier.

• Need not be an executable file.

There are four types of installation scripts with which you can perform customized actions:

• The request script

  The request script solicits data from the administrator installing a package for assigning or redefining environment variables.

• The checkinstall script

  The checkinstall script examines the target system for needed data, can set or modify package environment variables, and determines whether or not the installation proceeds.

  ---

  Note –

  The checkinstall script is available starting with the Solaris 2.5 and compatible releases.

  ---

• Procedure scripts

  Procedure scripts identify a procedure to be invoked before or after the installation or removal of a package. The four procedure scripts are preinstall, postinstall, preremove, and postremove.

• Class action scripts

  Class action scripts define an action or set of actions that should be applied to a class of files during installation or removal. You can define your own classes or use one of the four standard classes (sed, awk, build, and preserve).

Script Processing During Package Installation

The type of scripts you use depends on when the action of the script is needed during the installation process. As a package is installed, the pkgadd command performs the following steps:

1. Executes the request script.

   This is the only point at which your package can solicit input from the administrator installing the package.

2. Executes the checkinstall script.

   The checkinstall script gathers file system data and can create or alter environment variable definitions to control the subsequent installation. For more information on package environment variables, see Package Environment Variables.

3. Executes the preinstall script.

4. Installs package objects, for each class to be installed.

   Installation of these files occurs class by class, and class action scripts are executed accordingly. The list of classes operated on and the order in which they should be installed is initially defined with the CLASSES parameter in your pkginfo file. However, your request script or checkinstall script can change the value of the CLASSES parameter. For more information on how classes are processed during installation, see How Classes Are Processed During Installation.

   1. Creates symbolic links, devices, named pipes, and required directories.

   2. Installs the regular files (file types e, v, f), based on their class.

      The class action script is passed only regular files to install. All other package objects are created automatically from information in the pkgmap file.

   3. Creates all hard links.

5. Executes the postinstall script.

Script Processing During Package Removal

When a package is being removed, the pkgrm command performs these steps:

1. Executes the preremove script.

2. Removes the package objects, for each class.

   Removal also occurs class by class. Removal scripts are processed in the reverse order of installation, based on the sequence defined in the CLASSES parameter. For more information on how classes are processed during installation, see How Classes Are Processed During Installation.

   1. Removes hard links.

   2. Removes regular files.

   3. Removes symbolic links, devices, and named pipes.

3. Executes the postremove script.

The request script is not processed at the time of package removal. However, its output (a list of environment variables) is retained in the installed package and made available to removal scripts.

Package Environment Variables Available to Scripts

The following groups of environment variables are available to all installation scripts. Some of the environment variables can be modified by a request or checkinstall script.

• The request or checkinstall script can set or modify any of the standard parameters in the pkginfo file except for the required parameters. The standard installation parameters are described in detail in pkginfo(4).

  ---

  Note –

  The BASEDIR parameter can only be modified starting with the Solaris 2.5 and compatible releases.

  ---

• You can define your own installation environment variables by assigning values to them in the pkginfo file. Such environment variables must be alphanumeric with initial capital letters. Any of these environment variables can be changed by a request or checkinstall script.

• Both a request script and a checkinstall script can define new environment variables by assigning values to them and putting them in the installation environment.

• The table below lists environment variables that are available to all installation scripts through the environment. None of these can be modified by a script.

  Table 3–2 Package Environment Variables Available to Scripts

  Environment Variable	Description
  CLIENT_BASEDIR	The base directory with respect to the target system. While BASEDIR is the variable to use if you are referring to a specific package object from the install system (most likely a server), CLIENT_BASEDIR is the path to include in files placed on the client system. CLIENT_BASEDIR exists if BASEDIR exists and is identical to BASEDIR if there is no PKG_INSTALL_ROOT.
  INST_DATADIR	The directory where the package now being read is located. If the package is being read from a tape, this will be the location of a temporary directory where the package has been transferred into directory format. In other words, assuming there is no extension to the package name (for example, SUNWstuff.d), the request script for the current package would be found at $INST_DATADIR/$PKG/install.
  PATH	The search list used by sh to find commands on script invocation. PATH is usually set to /sbin:/usr/sbin:/usr/bin:/usr/sadm/install/bin.
  PKGINST	The instance identifier of the package being installed. If another instance of the package is not already installed, the value is the package abbreviation (for example, SUNWcadap). Otherwise, it is the package abbreviation followed by a suffix, such as SUNWcadap.4.
  PKGSAV	The directory where files can be saved for use by removal scripts or where previously saved files can be found. Available only in the Solaris 2.5 and compatible releases.
  PKG_INSTALL_ROOT	The root file system on the target system where the package is being installed. It exists only if the pkgadd and pkgrm commands were invoked with the -R option. This conditional existence facilitates its use in procedure scripts in the form ${PKG_INSTALL_ROOT}/somepath.
  PKG_NO_UNIFIED	Is an environment variable that gets set if the pkgadd and pkgrm commands were invoked with the -M and -R options. This environment variable is passed to any package installation script or package command that is part of the package environment.
  UPDATE	This environment variable does not exist under most installation environments. If it does exist (with the value yes), it means that a package with the same name, version, and architecture is already installed on the system or that this package is overwriting an installed package of the same name at the direction of the administrator. In these events, the original base directory is always used.

Obtaining Package Information for a Script

Two commands can be used from scripts to solicit information about a package:

• The pkginfo command returns information about software packages, such as the instance identifier and package name.

• The pkgparam command returns values for requested environment variables.

  See pkginfo(1), pkgparam(1), and Chapter 4, Verifying and Transferring a Package for more information.

Exit Codes for Scripts

Each script must exit with one of the exit codes shown in the following table.

See Chapter 5, Package Creation Case Studies for examples of exit codes returned by installation scripts.

All installation scripts delivered with your package should have an entry in the prototype file. The file type should be i (for package installation script).

Writing a request Script

The request script is the only way your package can interact directly with the administrator installing it. It can be used, for example, to ask the administrator if optional pieces of a package should be installed.

The output of a request script must be a list of environment variables and their values. This list can include any of the parameters you created in the pkginfo file and the CLASSES and BASEDIR parameters. The list can also introduce environment variables that have not been defined elsewhere (although the pkginfo file should always provide default values, when practical). For more information on package environment variables, see Package Environment Variables.

When your request script assigns values to a environment variable, it must then make those values available to the pkgadd command and other package scripts.

request Script Behaviors

• The request script cannot modify any files. It only interacts with administrators installing the package and creates a list of environment variable assignments based upon that interaction. To enforce this restriction, the request script is executed as the non-privileged user install if that user exists; otherwise it is executed as the non-privileged user nobody. The request script does not have superuser authority.

• The pkgadd command calls the request script with one argument that names the script's response file (the file that stores the administrator's responses).

• The request script is not executed during package removal. However, the environment variables assigned by the script are saved and are available during removal.

Design Rules for request Scripts

• There can be only one request script per package and it must be named request.

• The environment variable assignments should be added to the installation environment for use by the pkgadd command and other packaging scripts by writing them to the response file (known to the script as $1).

• System environment variables and standard installation environment variables, except for the CLASSES and BASEDIR parameters, cannot be modified by a request script. Any of the other environment variables you created can be changed.

  ---

  Note –

  A request script can only modify the BASEDIR parameter starting with the Solaris 2.5 and compatible releases.

  ---

• Every environment variable that the request script may manipulate should be assigned a default value in the pkginfo file.

• The format of the output list should be PARAM=value. For example:

  CLASSES=none class1

• The administrator's terminal is defined as standard input to the request script.

• Do not perform any special analysis of the target system in a request script. It is risky to test the system for the presence of certain binaries or behaviors, and set environment variables based upon that analysis, because there is no guarantee that the request script will actually be executed at install time. The administrator installing the package may provide a response file that will insert the environment variables without ever calling the request script. If the request script is also evaluating the target file system, that evaluation may not happen. An analysis of the target system for special treatment is best left to the checkinstall script.

If it is possible that the administrators who will be installing your package will be using the JumpStart^TM product, then the installation of your package must not be interactive. This implies that either you should not provide a request script with your package, or you need to communicate to the administrator that they should use the pkgask command, prior to installation, to store their responses to the request script. For more information on the pkgask command, see pkgask(1M).

How to Write a request Script

1. Make the directory containing your information files the current working directory.

2. Create a file named request with your favorite text editor.

3. Save your changes and quit the editor when you are done.

4. Complete one of the following tasks.

   • If you want to create additional installation scripts, skip to the next task, How to Gather File System Data.

   • If you have not created your prototype file, complete the procedure How to Create a prototype File Using the pkgproto Command, and skip to Step 5.

   • If you have already created your prototype file, edit it and add an entry for the installation script you just created.

5. Build your package.

   See How to Build a Package, if needed.

Where to Go Next

After you build the package, install it to confirm that it installs correctly and verify its integrity. Chapter 4, Verifying and Transferring a Package explains how to do this and provides step-by-step instructions on how to transfer your verified package to a distribution medium.

Example—Writing a request Script

When a request script assigns values to environment variables, it must make those values available to the pkgadd command. This example shows a request script segment that performs this task for the four environment variables CLASSES, NCMPBIN, EMACS, and NCMPMAN. (These were defined in an interactive session with the administrator earlier in the script.)

# make environment variables available to installation
# service and any other packaging script we might have
 
cat >$1 <<!
CLASSES=$CLASSES
NCMPBIN=$NCMPBI
EMACS=$EMACS
NCMPMAN=$NCMPMAN
!

Gathering Data With the checkinstall Script

The checkinstall script is executed shortly after the optional request script. It runs as the user install, if such a user exists, or the user nobody. The checkinstall script does not have the authority to change file system data; it is strictly a data gatherer. However, based on the information it gathers, it can create or modify environment variables in order to control the course of the resulting installation. It is also capable of cleanly halting the installation process.

The checkinstall script is intended to perform basic checks on a file system that would not be normal for the pkgadd command. For example, it can be used to check ahead to determine if any files from the current package are going to overwrite existing files, or manage general software dependencies (the depend file only manages package-level dependencies).

Unlike the request script, the checkinstall script is executed whether or not a response file is provided; and, its presence does not brand the package as “interactive.” This means that the checkinstall script can be used in situations where a request script is forbidden or administrative interaction is not practical.

The checkinstall script is available starting with the Solaris 2.5 and compatible releases.

checkinstall Script Behaviors

• The checkinstall script cannot modify any files. It only analyzes the state of the system and creates a list of environment variable assignments based upon that interaction. To enforce this restriction, the checkinstall script is executed as the non-privileged user install if that user exists; otherwise it is executed as the non-privileged user nobody. The checkinstall script does not have superuser authority.

• The pkgadd command calls the checkinstall script with one argument that names the script's response file (the file that stores the administrator's responses).

• The checkinstall script is not executed during package removal. However, the environment variables assigned by the script are saved and are available during removal.

Design Rules for checkinstall Scripts

• There can be only one checkinstall script per package and it must be named checkinstall.

• The environment variable assignments should be added to the installation environment for use by the pkgadd command and other packaging scripts by writing them to the response file (known to the script as $1).

• System environment variables and standard installation environment variables, except for the CLASSES and BASEDIR parameters, cannot be modified by a checkinstall script. Any of the other environment variables you created can be changed.

• Every environment variable that the checkinstall script may manipulate should be assigned a default value in the pkginfo file.

• The format of the output list should be PARAM=value. For example:

  CLASSES=none class1

• Administrator interaction is not permitted during execution of a checkinstall script. All administrator interaction is restricted to the request script.

How to Gather File System Data

1. Make the directory containing your information files the current working directory.

2. Create a file named checkinstall with your favorite text editor.

3. Save your changes and quit the editor when you are done.

4. Complete one of the following tasks.

   • If you want to create additional installation scripts, skip to the next task, How to Write Procedure Scripts.

   • If you have not created your prototype file, complete the procedure How to Create a prototype File Using the pkgproto Command, and skip to Step 5.

   • If you have already created your prototype file, edit it and add an entry for the installation script you just created.

5. Build your package.

   See How to Build a Package, if needed.

Where to Go Next

After you build the package, install it to confirm that it installs correctly and verify its integrity. Chapter 4, Verifying and Transferring a Package explains how to do this and provides step-by-step instructions on how to transfer your verified package to a distribution medium.

Example—Writing a checkinstall Script

This example checkinstall script checks to see if database software needed by the SUNWcadap package is installed.

# checkinstall script for SUNWcadap
#
# This confirms the existence of the required specU database
 
# First find which database package has been installed.
pkginfo -q SUNWspcdA	# try the older one
 
if [ $? -ne 0 ]; then
   pkginfo -q SUNWspcdB	# now the latest
 
	  if [ $? -ne 0 ]; then	# oops
		    echo "No database package can be found. Please install the"
		    echo "SpecU database package and try this installation again."
		    exit 3		# Suspend
	  else
		    DBBASE="`pkgparam SUNWsbcdB BASEDIR`/db"	# new DB software
	  fi
else
	  DBBASE="`pkgparam SUNWspcdA BASEDIR`/db"	# old DB software
fi
 
# Now look for the database file we will need for this installation
if [ $DBBASE/specUlatte ]; then
	  exit 0		# all OK
else
	  echo "No database file can be found. Please create the database"
	  echo "using your installed specU software and try this"
	  echo "installation again."
	  exit 3		# Suspend
fi
 

Writing Procedure Scripts

The procedure scripts provide a set of instructions to be performed at particular points in package installation or removal. The four procedure scripts must be named one of the predefined names, depending on when the instructions are to be executed, and are executed without arguments.

• The preinstall script

  Runs before class installation begins. No files should be installed by this script.

• The postinstall script

  Runs after all volumes have been installed.

• The preremove script

  Runs before class removal begins. No files should be removed by this script.

• The postremove script

  Runs after all classes have been removed.

Procedure Script Behaviors

Procedure scripts are executed as uid=root and gid=other.

Design Rules for Procedure Scripts

• Each script should be able to be executed more than once since it is executed once for each volume in a package. This means that executing a script any number of times with the same input produces the same results as executing the script only once.

• Each procedure script that installs a package object not in the pkgmap file must use the installf command to notify the package database that it is adding or modifying a path name. After all additions or modifications are complete, this command should be invoked with the -f option. Only postinstall and postremove scripts may install package objects in this way. See installf(1M) and Chapter 5, Package Creation Case Studies for more information.

• Administrator interaction is not permitted during execution of a procedure script. All administrator interaction is restricted to the request script.

• Each procedure script that removes files not installed from the pkgmap file must use the removef command to notify the package database that it is removing a path name. After removal is complete, this command should be invoked with the -f option. See removef(1M) and Chapter 5, Package Creation Case Studies for details and examples.

  ---

  Note –

  The installf and removef commands must be used because procedure scripts are not automatically associated with any path names listed in the pkgmap file.

  ---

How to Write Procedure Scripts

1. Make the directory containing your information files the current working directory.

2. Create one or more procedure scripts with your favorite text editor.

   A procedure script must be named one of the predefined names: preinstall, postinstall, preremove, or postremove.

3. Save your changes and quit the editor.

4. Complete one of the following tasks.

   • If you want to create class action scripts, skip to the next task, How to Write Class Action Scripts.

   • If you have not created your prototype file, complete the procedure How to Create a prototype File Using the pkgproto Command, and skip to Step 5.

   • If you have already created your prototype file, edit it and add an entry for each installation script you just created.

5. Build your package.

   See How to Build a Package, if needed.

Where to Go Next

After you build the package, install it to confirm that it installs correctly and verify its integrity. Chapter 4, Verifying and Transferring a Package explains how to do this and provides step-by-step instructions on how to transfer your verified package to a distribution medium.

Writing Class Action Scripts

Defining Object Classes

Object classes allow a series of actions to be performed on a group of package objects at installation or removal. You assign objects to a class in the prototype file. All package objects must be given a class, although the class of none is used by default for objects that require no special action.

The installation parameter CLASSES, defined in the pkginfo file, is a list of classes to be installed (including the none class).

Objects defined in the pkgmap file that belong to a class not listed in this parameter in the pkginfo file will not be installed.

The CLASSES list determines the order of installation. Class none is always installed first, if present, and removed last. Since directories are the fundamental support structure for all other file system objects, they should all be assigned to the none class. Exceptions can be made, but as a general rule, the none class is safest. The reason for this is to ensure that the directories are created before the objects they will contain and also to ensure that no attempt is made to delete a directory before it has been emptied.

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.

How Classes Are Processed During Removal

Objects are removed class by class. Classes that exist for a package but that are not listed in the CLASSES parameter are removed first (for example, an object installed with the installf command). Classes listed in the CLASSES parameter are removed in reverse order. The none class is always removed last. The following list describes the system actions that occur when a class is removed:

1. The pkgrm command creates a path name list.

   The pkgrm command creates a list of installed path names that belong to the indicated class. Path names referenced by another package are excluded from the list unless their file type is e (meaning the file should be edited upon installation or removal).

   If the package being removed modified any files of type e during installation, it should remove just the lines it added. Do not delete a non-empty editable file; just remove the lines the package added.

2. If there is no class action script, the path names are deleted.

   If your package has no removal class action script for the class, all the path names in the list generated by the pkgrm command are deleted.

   ---

   Note –

   Files with a file type of e (editable), which are not assigned to a class and an associated class action script, will be removed at this point, even if the path name is shared with other packages.

   ---

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

   The pkgrm command invokes the class action script with standard input for the script containing the list generated in item 1.

4. The pkgrm command performs an audit.

   After successfully executing the class action script, the pkgrm command removes knowledge of the path names from the package database unless a path name is referenced by another package.

The Class Action Script

The class action script defines a set of actions to be executed during installation or removal of a package. The actions are performed on a group of path names based on their class definition. (See Chapter 5, Package Creation Case Studies for examples of class action scripts.)

The name of a class action script is based on the class on which it should operate and whether those operations should occur during package installation or removal. The two name formats are as follows:

For example, the name of the installation script for a class named manpage would be i.manpage and the removal script would be named r.manpage.

This file name format is not used for files belonging to the sed, awk, or build system classes. For more information on these special classes, see The Special System Classes.

Class Action Script Behaviors

• Class action scripts are executed as uid=root and gid=other.

• A script is executed for all files in the given class on the current volume (for example, floppy disk).

• The pkgadd and pkgrm commands create a list of all objects listed in the pkgmap file that belong to the class. As a result, a class action script can act only upon path names defined in the pkgmap that belong to a particular class.

• When a class action script is executed for the last time (that is, no more files are found belonging to that class), the class action script will be executed once with the keyword argument ENDOFCLASS.

• Administrator interaction is not permitted during execution of a class action script.

Design Rules for Class Action Scripts

• If a package spans more than one volume, the class action script is executed once for each volume that contains at least one file belonging to a class. Consequently, each script must be able to be executed more than once. This means that executing a script any number of times with the same input must produce the same results as executing the script only once.

• When a file is part of a class that has a class action script, the script must install the file. The pkgadd command does not install files for which a class action script exists, although it does verify the installation.

• A class action script should never add, remove, or modify a path name or system attribute that does not appear in the list generated by the pkgadd command. For more information on this list, see item 1 in How Classes Are Processed During Installation.

• When your script sees the ENDOFCLASS argument, put post-processing actions (like clean up) into your script.

• All administrator interaction is restricted to the request script. Do not try to obtain information from the administrator using a class action script.

The Special System Classes

The system provides four special classes. They are:

• The sed class

  Provides a method for using sed instructions to edit files upon package installation and removal.

• The awk class

  Provides a method for using awk instructions to edit files upon package installation and removal.

• The build class

  Provides a method to dynamically construct or modify a file using Bourne shell commands.

• The preserve class

  Provides a method to preserve files that should not be overwritten by future package installations.

If there are several files in a package that require special processing that can be fully defined through sed, awk, or sh commands, installation will be faster by using the system classes rather than multiple classes and their corresponding class action scripts.

The sed Class Script

The sed class provides a method to modify an existing object on the target system. The sed class action script executes automatically at installation if a file belonging to class sed exists. The name of the sed class action script should be the same as the name of the file on which the instructions will be executed.

A sed class action script delivers sed instructions in the format shown in the figure below.

Figure 3–1 Format of a sed Class Action Script

# comment, which may appear on any line in the file
 
!install
# sed(1) instructions which will be invoked during
# installation of the object
 
[address [,address]] function [arguments]
 
  . . .
 
!remove
 
# sed(1) instructions to be invoked during the removal process
 
[address [,address]] function [arguments]

Two commands indicate when instructions should be executed. The sed instructions that follow the !install command are executed during package installation and those that follow the !remove command are executed during package removal. It does not matter which order these commands are used in the file.

For more information on sed instructions, see sed(1). For examples of sed class action scripts, see Chapter 5, Package Creation Case Studies.

The awk Class Script

The awk class provides a method to modify an existing object on the target system. Modifications are delivered as awk instructions in an awk class action script.

The awk class action script is executed automatically at installation if a file belonging to class awk exists. Such a file contains instructions for the awk class script in the format shown in the figure below.

Figure 3–2 Format of an awk Class Action Script

# comment, which may appear on any line in the file
 
!install
 
# awk(1) program to install changes
 
 . . . (awk program)
 
!remove
 
# awk1(1) program to remove changes
 
 . . . (awk program)

Two commands indicate when instructions should be executed. The awk instructions that follow the !install command are executed during package installation, and those that follow the !remove command are executed during package removal. It does not matter in which order these commands are used in the file.

The name of the awk class action script should be the same as the name of the file on which the instructions will be executed.

The file to be modified is used as input to awk and the output of the script ultimately replaces the original object. Environment variables may not be passed to the awk command with this syntax.

For more information on awk instructions, see awk(1).

The build Class Script

The build class creates or modifies a package object file by executing Bourne shell instructions. These instructions are delivered as the package object, which runs automatically at installation if it belongs to the build class.

The name of the build class action script should be the same as the name of the file on which the instructions will be executed, and must be executable by the sh command. The script's output becomes the new version of the file as it is built or modified. If the script produces no output, the file will not be created or modified. Therefore, the script can modify or create the file itself.

For example, if a package delivers a default file, /etc/randomtable, and if the file does not already exist on the target system, the prototype file entry might be:

e build /etc/randomtable ? ? ?

and the package object, /etc/randomtable, might look like this:

!install
# randomtable builder
if [ -f $PKG_INSTALL_ROOT/etc/randomtable ]; then
		echo "/etc/randomtable is already in place.";
	    else
		echo "# /etc/randomtable" > $PKG_INSTALL_ROOT/etc/randomtable
		echo "1121554	# first random number" >> $PKG_INSTALL_ROOT/etc/randomtable
fi
 
!remove
# randomtable deconstructor
if [ -f $PKG_INSTALL_ROOT/etc/randomtable ]; then
		# the file can be removed if it's unchanged
		if [ egrep "first random number" $PKG_INSTALL_ROOT/etc/randomtable ]; then
			rm $PKG_INSTALL_ROOT/etc/randomtable;
		fi
fi
 

See Chapter 5, Package Creation Case Studies for another example using the build class.

The preserve Class Script

The preserve class preserves a package object file by determining whether or not an existing file should be overwritten when the package is installed. Two possible scenarios when using a preserve class script are:

• If the file to be installed does not already exist in the target directory, the file will be installed normally.

• If the file to be installed exists in the target directory, a message describing the file exists is displayed, and the file is not installed.

Both scenario outcomes are considered successful by the preserve script. A failure occurs only, when in the second scenario, the file is unable to be copied to the target directory.

Starting with the Solaris 7 release, the i.preserve script and a copy of this script, i.CONFIG.prsv, can be found in the /usr/sadm/install/scripts directory with the other class action scripts.

Modify the script to include the filename or filenames you would like to preserve.

How to Write Class Action Scripts

1. Make the directory containing your information files the current working directory.

2. Assign the package objects in the prototype file the desired class names. For example, assigning objects to an application and manpage class would look like:

   f manpage /usr/share/man/manl/myappl.1l f application /usr/bin/myappl

3. Modify the CLASSES parameter in the pkginfo file to contain the class names you want to use in your package. For example, entries for the application and manpage classes would look like:

   CLASSES=manpage application none

   ---

   Note –

   The none class is always installed first and removed last, regardless of where it appears in the definition of the CLASSES parameter.

   ---

4. If you are a creating class action script for a file belonging to the sed, awk, or build class, make the directory containing the package object your current working directory.

5. Create the class action scripts or package objects (for files belonging to the sed, awk, or build class). An installation script for a class named application would be named i.application and a removal script would be named r.application.

   Remember, when a file is part of a class that has a class action script, the script must install the file. The pkgadd command does not install files for which a class action script exists, although it does verify the installation. And, if you define a class but do not deliver a class action script, the only action taken for that class is to copy components from the installation medium to the target system (the default pkgadd behavior).

6. Complete one of the following tasks.

   • If you have not created your prototype file, complete the procedure How to Create a prototype File Using the pkgproto Command, and skip to Step 7.

   • If you have already created your prototype file, edit it and add an entry for each installation script you just created.

7. Build your package.

   See How to Build a Package, if needed.

Where to Go Next

After you build the package, install it to confirm that it installs correctly and verify its integrity. Chapter 4, Verifying and Transferring a Package explains how to do this and provides step-by-step instructions on how to transfer your verified package to a distribution medium.