TweetFollow Us on Twitter

Ship It! Distributing Your Software, Part 2

Volume Number: 20 (2004)
Issue Number: 2
Column Tag: Programming

Mac OS X Programming Secrets

by Scott Knaster

Ship It! Distributing Your Software, Part 2

In our last thrilling installment (or was it a thrilling installation?), we discussed the simplest method of distribution for your Mac OS X software: disk images. We talked about using Disk Copy or Disk Utility to make a disk image, and we described the relatively recent technology of Internet-enabling a disk image so that it cleans up after itself when users download it in Safari.

When you distribute software on a disk image, there is no actual installing taking place. Users simply drag and drop files onto their hard disks. That's the great strength and weakness of disk images: they're easy for you to make and easy for users to figure out, but you can quickly run into their limitations. For example, what if you need to make sure files end up in specific places on the disk? What about checking the progress of the installation and taking some action based on what's happening? Most commercial applications need to do things like this when they're installed. For more control of the installation process, Apple provides the PackageMaker and Installer tools.

Meet Your Maker

PackageMaker is an application that comes with Mac OS X. You use PackageMaker to create packages, which are documents with extension .pkg that contain files to be installed and related files used during the installation. An Apple application called Installer reads the information from a package and performs the installation.

The two biggest tricks PackageMaker installations can do that disk images can't are installing files anywhere in the system, and running scripts while the installation is happening. To install files where you want them, you'll create a directory structure in your package that shows how you want files installed in the system, and includes a few extra items used by the installation itself. In order to run scripts, Installer defines certain events in the installation process and looks for scripts with names corresponding to those events. If the scripts exist, Installer runs them.

Let's take a deeper look at setting up your files and scripts for installation. Please gaze directly into the magazine.

Everything in its right place

You'll make a set of directories and files that indicates where you want everything to end up after the installation. The basic pieces of the directory structure are as follows:

  • You'll create a directory that contains all the other directories and files in the package. This directory can have any name, such as "PackageContents" or "Fred". When you run PackageMaker, you locate this folder.

  • Within the all-enclosing directory, you'll have a directory that holds various files used for installation, such as install-time scripts, the license and readme docs, and so on. Again, this directory can have any name - you specify it in PackageMaker.

  • A second directory inside the outermost directory holds the files to be installed. They're arranged in directories according to the way you want them to be installed. When you run PackageMaker, you specify whether you the files can be installed anywhere or must be placed in absolute locations in the system.

Here's an example. Let's say we're going to install a package that consists of a music application, 3 system sounds, and a screen saver module. Our package directory structure would look like this:

PackageContents
   PackageRoot
      Applications
         Music2MyEars
      System
         Library
            Sounds
               sound1.aiff
               sound2.aiff
               sound3.aiff
            Screen Savers
               ears.saver
   PackageResources
      License.rtf
      ReadMe.rtf
      preflight
      preinstall
      postinstall 
      postflight

The files in the PackageRoot directory are the software itself. We want the files installed in specific locations. When we run PackageMaker to create the package, we can make sure that will happen.

The PackageResources directory is filled with files that will be used during the installation. These include the ReadMe and license documents, along with several scripts (preflight, preinstall, etc.) that Installer will run. In this example, our text files are RTF, but you can also use .txt or .html files.

Staying in Control

When the user runs Installer, usually by double-clicking a .pkg file, these are the steps that take place:

  • Installer looks in the package for an InstallationCheck script and runs it, if it's there. This script provides an opportunity to cancel the installation by returning a nonzero value.

  • If there's a Welcome file (such as Welcome.rtf or Welcome.html), Installer displays it. Otherwise, a default Welcome screen appears. If there's a background image (a file named "background" with extension .tiff, .jpg, .gif, .pdf, or .eps), it's displayed behind the Welcome.

  • If there's a ReadMe file (such as ReadMe.rtf or ReadMe.html), it's displayed next.

  • Next, the License file is displayed.

  • When the user gets to the Select a Destination screen, Installer runs the VolumeCheck script (if it exists) for each mounted volume. VolumeCheck can return a nonzero value to prevent a volume from being eligible for installation.

  • After the user clicks Install, the preflight script is run. Like the other scripts, preflight can cancel the installation by returning a nonzero value.

  • If the user is upgrading the package from a previous version, Installer runs the preupgrade script. Otherwise, preinstall is run.

  • The package contents are copied to the destination. Actual installing, wow!

  • If this was an upgrade, the postupgrade script is run. Otherwise, postinstall is run. There's still time to cancel the installation, which happens if these scripts return nonzero.

Installer runs the postflight script, if it's present.

As you can see from these steps, you have a chance to check the installation with many different scripts: InstallationCheck and VolumeCheck, preflight, preinstall or preupgrade, postinstall or postupgrade, and postflight. You should specify a shell in the first line of your script, using the !#/bin/sh convention. Installer provides a bunch of arguments and environment variables you can use in the scripts. For example, the first argument ($1) is the full path to the installation package, $2 is the path to the destination, and $3 is the mountpoint of the destination volume.

Pack it Up

Once you have written the scripts you want, created the ReadMe and related files, and assembled everything in the right directories with your installation files, it's time to make the package itself. You do this by running PackageMaker, which is located in Developer/Applications/Utilities/. When you run PackageMaker, you see the lovely screen that appears in Figure 1. It's safe to say Jonathan Ive hasn't gotten hold of this one yet.


Figure 1. This is the screen that appears when you launch PackageMaker. It's not very pretty, but it works just fine.

To start assembling your package, fill out the fields on the Description tab. The Title and Description fields provide a place for information that's visible to users when the Installer is running. Click the Files tab to specify the source location of the files to be installed. In our example above, this is the PackageRoot directory. Just to be macho, note that the field for the directory is editable text, so if you're really geeky and you hate clicking through a file dialog, you can actually type the directory path yourself.

Next, use the Resources tab to specify where the scripts, ReadMe, and similar files are located. In our earlier example, this was the PackageResources directory.

The Info tab provides a few interesting options. For example, you can choose whether to recommend or require a restart here. Restarting is mean and should be avoided whenever possible. (In Panther, you can also specify that logout is required, but you can't do it here: you have to modify the Info.plist to do so. To make this happen, add an "IFPkgFlagRestartAction" key with a value of "RequiredLogout" to the package's Info.plist.) If your software doesn't have to be installed in a particular location, check the Relocatable box and users will get to pick where your software should go. The last tab, Version, lets you specify info that appears in the Finder.

When you have your package just the way you want, you should save in PackageMaker, then choose File * Create Package to make the package. When you double-click the package, Installer will launch and you'll get the exciting display you see in Figure 2.


Figure 2. The Installer opening screen can display custom text and background image.

There are a few more Installer features that aren't available in PackageMaker. Instead, you have to edit the package's Info.plist file to get them. For example, when you include a background image in your package, Installer stretches it out to fill the entire window, which is ugly if the image has the wrong proportions. You can gain more control over how the image is used by editing the Info.plist file with Property List Editor.

In the package shown in Figure 2, the Info.plist file has two new keys added to it: IFPkgFlagBackgroundScaling and IFPkgFlagBackgroundAlignment, to make sure that that bee and that guy don't take over the screen. The first key, which controls how the image is scaled, is set to "none". You can also use "tofit" (the default) and "proportional". The second key, for alignment, is set to "bottomleft". Other valid alignments are "left", "right", "top", "bottom", "center" (the default), "topleft", "topright", and "bottomright".

PackageMaker has a few more tricks, such as the ability to create metapackages, which are packages that contain and install other packages. Metapackages can present and sort through complex sets of dependencies for installing software. Another cool feature is the ability to install packages across a network, which you can do if you have Apple Remote Desktop.

Installermania

PackageMaker isn't the last word in installers. Lots of commercial software requires more control than you can get from PackageMaker and Installer. The best-known non-Apple installer packages are made by MindVision Software (InstallerVise, ViseX, and FileStorm), and Aladdin (StuffIt InstallerMaker). These applications let you do things that are beyond PackageMaker, such as creating installs that work on OS 9 or Windows, displaying multiple "tips" screens during install, and automatically adding items to the OS X dock. These products compete with free software from Apple, so they have to be feature-packed.

You can find out more, or even download whole manuals and applications, by visiting the web sites at www.mindvision.com and www.stuffit.com/mac/installermaker/. MindVision downloads are fully functional, with limits on the installers you build until you buy a registration key. The InstallerMaker download is fully functional, but produces installers that say you're using an unregistered copy.

Speaking of free stuff, Apple provides a pile of fine documentation on packages, PackageMaker, and related topics. For much more detail on the stuff we talked about in this article, check out the following URL:

http://developer.apple.com/documentation/DeveloperTools/Conceptual/SoftwareDistribution.

Have fun getting your installer together. Remember, no matter how hard you work on your application, nobody will be able to use it unless you produce an installer, disk image, or other trick to get it out into the world.


Scott Knaster has been playing with Apple computers, and occasionally working with them, since 1977. Wow, that's a long time! Scott has written books and articles for normal human beings as well as programmers. Photo of Scott and his friend Jollibee courtesy of John Vink Photography.

 
AAPL
$103.39
Apple Inc.
+0.89
MSFT
$44.97
Microsoft Corpora
-0.46
GOOG
$574.33
Google Inc.
+2.73

MacTech Search:
Community Search:

Software Updates via MacUpdate

NetShade 6.0.2 - Browse privately using...
NetShade is an Internet security tool that conceals your IP address on the web. NetShade routes your Web connection through either a public anonymous proxy server, or one of NetShade's own dedicated... Read more
Mac DVDRipper Pro 5.0 - Copy, backup, an...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
pwSafe 3.1 - Secure password management...
pwSafe provides simple and secure password management across devices and computers. pwSafe uses iCloud to keep your password databases backed-up and synced between Macs and iOS devices. It is... Read more
StatsBar 1.8 - Monitor system processes...
StatsBar gives you a comprehensive and detailed analysis of the following areas of your Mac: CPU usage Memory usage Disk usage Network and bandwidth usage Battery power and health (MacBooks only)... Read more
Path Finder 6.5.5 - Powerful, award-winn...
Path Finder is a file browser that combines the familiar Finder interface with the powerful utilities and innovative features. Just a small selection of the Path Finder 6 feature set: Dual pane... Read more
QuarkXPress 10.2.1 - Desktop publishing...
With QuarkXPress, you can communicate in all the ways you need to -- and always look professional -- in print and digital media, all in a single tool. Features include: Easy to Use -- QuarkXPress is... Read more
Skype 6.19.0.450 - Voice-over-internet p...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
VueScan 9.4.41 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
Cloud 3.0.0 - File sharing from your men...
Cloud is simple file sharing for the Mac. Drag a file from your Mac to the CloudApp icon in the menubar and we take care of the rest. A link to the file will automatically be copied to your clipboard... Read more
LibreOffice 4.3.1.2 - Free Open Source o...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more

Latest Forum Discussions

See All

Alien Creeps TD Review
Alien Creeps TD Review By Jennifer Allen on September 2nd, 2014 Our Rating: :: EXPENSIVE DEFENSESUniversal App - Designed for iPhone and iPad Alien Creeps TD would be a fun if unremarkable Tower Defense game, but its heavy focus on... | Read more »
Function Space, a Social Network App for...
Function Space, a Social Network App for Science, Launches on iOS Posted by Ellis Spice on September 2nd, 2014 [ permalink ] | Read more »
Treasure Tombs: Ra Deal Coming from Bulk...
Treasure Tombs: Ra Deal Coming from Bulkypix and Dark Tonic This Fall Posted by Jessica Fisher on September 2nd, 2014 [ permalink ] Dark Tonic and | Read more »
Tiny Tower Vegas Review
Tiny Tower Vegas Review By Jennifer Allen on September 2nd, 2014 Our Rating: :: STEADY DEVELOPMENTUniversal App - Designed for iPhone and iPad Build a huge tower again but Vegas-style in Tiny Tower Vegas.   | Read more »
The Manhattan Project Review
The Manhattan Project Review By Andrew Fisher on September 2nd, 2014 Our Rating: :: ROCKET SCIENCEUniversal App - Designed for iPhone and iPad The Manhattan Project offers a great Euro-style gameplay experience, but it is totally... | Read more »
Rhonna Designs Magic (Photography)
Rhonna Designs Magic 1.0 Device: iOS Universal Category: Photography Price: $1.99, Version: 1.0 (iTunes) Description: Want to sprinkle *magic* on your photos? With RD Magic, you can add colors, filters, light leaks, bokeh, edges,... | Read more »
This Week at 148Apps: August 25-29, 2014
Shiny Happy App Reviews   | Read more »
Qube Kingdom – Tips, Tricks, Strategies,...
Qube Kingdom is a tower defense game from DeNA. You rally your troops – magicians, archers, knights, barbarians, and others – and fight against an evil menace looking to dominate your kingdom of tiny squares. Planning a war isn’t easy, so here are a... | Read more »
Qube Kingdom Review
Qube Kingdom Review By Nadia Oxford on August 29th, 2014 Our Rating: :: KIND OF A SQUARE KINGDOMUniversal App - Designed for iPhone and iPad Qube Kingdom has cute visuals, but it’s a pretty basic tower defense game at heart.   | Read more »
Fire in the Hole Review
Fire in the Hole Review By Rob Thomas on August 29th, 2014 Our Rating: :: WALK THE PLANKUniversal App - Designed for iPhone and iPad Seafoam’s Fire in the Hole looks like a bright, 8-bit throwback, but there’s not enough booty to... | Read more »

Price Scanner via MacPrices.net

Apple refurbished iPads available for up to $...
Apple is offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. Stock tends to come and go with some of these... Read more
Are We Now In The Post-Post-PC Era?
A longtime and thoroughgoing laptop aficionado, I was more than a little dismayed by Steve Jobs’s declaration back in 2010 when he sprang the iPad on an unsuspecting world. that we’d entered a “post-... Read more
PC Outlook Improves, But 2014 Shipments Still...
According to the International Data Corporation (IDC) Worldwide Quarterly PC Tracker, worldwide PC shipments are expected to fall by -3.7 percent in 2014. To hat’s actually an improvement from the... Read more
IDC Lowers Tablet Sales Projections for 2014...
Following a second consecutive quarter of softer than expected demand, International Data Corporation (IDC) has lowered its worldwide tablet plus 2-in-1 forecast for 2014 to 233.1 million units. The... Read more
Apple now offering refurbished 21-inch 1.4GHz...
The Apple Store is now offering Apple Certified Refurbished 21″ 1.4GHz iMacs for $929 including free shipping plus Apple’s standard one-year warranty. Their price is $170 off the cost of new models,... Read more
Save $50 on the 2.5GHz Mac mini, on sale for...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $300 on an iMac with Apple refurbi...
The Apple Store has Apple Certified Refurbished iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... Read more
The Rise of Phablets
Carlisle & Gallagher Consulting Group, a businesses and technology consulting firm focused solely on the financial services industry, has released an infographic depicting the convergence of... Read more
Bad Driver Database App Allows Good Drivers t...
Bad Driver Database 1.4 by Facile Group is a new iOS and Android app that lets users instantly input and see how many times a careless, reckless or just plain stupid driver has been added to the... Read more
Eddy – Cloud Music Player for iPhone/iPad Fre...
Ukraine based CapableBits announces the release of Eddy, its tiny, but smart and powerful cloud music player for iPhone and iPad that allows users to stream or download music directly from cloud... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.