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.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Logic Pro X 10.1.1 - Music creation and...
Apple Logic Pro X is the most advanced version of Logic ever. Sophisticated new tools for professional songwriting, editing, and mixing are built around a modern interface that's designed to get... Read more
VLC Media Player 2.2.0 - Popular multime...
VLC Media Player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, MP3, OGG, ...) as well as DVDs, VCDs, and various streaming protocols. It... Read more
Sound Studio 4.7.8 - Robust audio record...
Sound Studio lets you easily record and professionally edit audio on your Mac. Easily rip vinyls and digitize cassette tapes, or record lectures and voice memos. Prepare for live shows with live... Read more
LibreOffice 4.4.1.2 - Free, open-source...
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
Freeway Pro 7.0.3 - Drag-and-drop Web de...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With its user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more
Cloud 3.3.0 - 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
Cyberduck 4.6.5 - FTP and SFTP browser....
Cyberduck is a robust FTP/FTP-TLS/SFTP browser for the Mac whose lack of visual clutter and cleverly intuitive features make it easy to use. Support for external editors and system technologies such... Read more
Firefox 36.0 - Fast, safe Web browser. (...
Firefox for Mac offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals and... Read more
Thunderbird 31.5.0 - Email client from M...
As of July 2012, Thunderbird has transitioned to a new governance model, with new features being developed by the broader free software and open source community, and security fixes and improvements... Read more
VOX 2.4 - Music player that supports man...
VoxIt just sounds better! The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features & support for all audio formats you should ever need... Read more

Get The Whole Story – Lone Wolf Complete...
Get The Whole Story – Lone Wolf Complete is Now Available and On Sale Posted by Jessica Fisher on February 27th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Who Wore it Best? The Counting Dead vs....
Like it or not, the “clicker” genre, popularized by cute distractions like Candy Box and Cookie Clicker, seems like it’s here to stay. So Who Wore it Best? takes a look at two recent examples: The Counting Dead and AdVenture Capitalist. | Read more »
Card Crawl, the Mini Deck Building Game,...
Card Crawl, the Mini Deck Building Game, is Coming Soon Posted by Jessica Fisher on February 27th, 2015 [ permalink ] Tinytouchtales and Mexer have announced their new game, | Read more »
Witness an all new puzzle mechanic in Bl...
Well, BlastBall MAX is not one of those games and is bucking trends such as timers, elements of randomness, and tacked-on mechanics in favor of pure puzzle gameplay. When you first boot up the game you’ll see a grid made up of squares that are each... | Read more »
This Princess Has a Dragon and She isn’t...
This Princess Has a Dragon and She isn’t Afraid to Useit. | Read more »
Mecha Showdown Review
Mecha Showdown Review By Lee Hamlet on February 27th, 2015 Our Rating: :: IN A SPINUniversal App - Designed for iPhone and iPad Mecha Showdown replaces traditional buttons with a slot machine mechanic in this robot fighting game,... | Read more »
Reliance Games and Dreamworks Unveil Rea...
Reliance Games and Dreamworks Unveil Real Steel Champions Posted by Ellis Spice on February 27th, 2015 [ permalink ] Reliance Games and Dreamworks have announced that a third game in | Read more »
Sum Idea Review
Sum Idea Review By Jennifer Allen on February 27th, 2015 Our Rating: :: TAXING NUMBERSUniversal App - Designed for iPhone and iPad Sum Idea is a fairly charming but taxing puzzle game.   | Read more »
A New Badland Update Brings Daydream Lev...
A New Badland Update Brings Daydream Levels to Co-Op Posted by Ellis Spice on February 27th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Slashing Demons Review
Slashing Demons Review By Lee Hamlet on February 27th, 2015 Our Rating: :: IT'S A LONG WAY TO THE TOPUniversal App - Designed for iPhone and iPad Slashing Demons lacks the depth or scope to take it beyond the point of being just... | Read more »

Price Scanner via MacPrices.net

Apple CEO Tim Cook to Deliver 2015 George Was...
Apple CEO Tim Cook will deliver the George Washington University’s Commencement address to GWU grads on May 17, at which time he will also be awarded an honorary doctorate of public service from the... Read more
Apple restocks refurbished Mac minis for up t...
The Apple Store has restocked Apple Certified Refurbished 2014 Mac minis, with models available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz... Read more
Save up to $50 on iPad Air 2s, NY tax only, f...
 B&H Photo has iPad Air 2s on sale for $50 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469.99 $30 off - 64GB iPad Air 2 WiFi: $549 $50 off - 128GB iPad Air 2... Read more
16GB iPad Air 2 on sale for $447, save $52
Walmart has the 16GB iPad Air 2 WiFi on sale for $446.99 on their online store for a limited time. Choose free shipping or free local store pickup (if available). Sale price for online orders only,... Read more
iMacs on sale for up to $205 off MSRP
B&H Photo has 21″ and 27″ iMacs on sale for up to $205 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1029 $70 off - 21″ 2.7GHz iMac: $1199 $100 off - 21″ 2.9GHz... Read more
Apple Takes 89 Percent Share of Global Smartp...
According to the latest research from Strategy Analytics, global smartphone operating profit reached US$21 billion in Q4 2014. The Android operating system captured a record-low 11 percent global... Read more
New Travel Health App “My Travel Health” iOS...
Rochester, Minnesota based Travel Health and Wellness LLC has announced that its new iOS app help safeguard the user’s health when traveling abroad — “My Travel Health” is now available on the Apple... Read more
Sale! MacBook Airs for up to $115 off MSRP
B&H Photo has MacBook Airs on sale for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 128GB MacBook Air: $799 100 off MSRP - 11″ 256GB MacBook Air: $999 $100... Read more
15-inch 2.0GHz Retina MacBook Pro (refurbishe...
The Apple Store has Apple Certified Refurbished previous-generation 15″ 2.0GHz Retina MacBook Pros available for $1489 including free shipping plus Apple’s standard one-year warranty. Their price is... Read more
Wither The iPad mini? End Of The Road Imminen...
AppleDailyReport’s Dennis Sellers predicts that the iPad mini is going to be left to wither on the vine, as it were, and then just allowed to fade away — a casualty of the IPhone 6 Plus and other... Read more

Jobs Board

Sr. Technical Services Consultant, *Apple*...
**Job Summary** Apple Professional Services (APS) has an opening for a senior technical position that contributes to Apple 's efforts for strategic and transactional Read more
Event Director, *Apple* Retail Marketing -...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global engagement strategy and team. Delivering an overarching brand Read more
*Apple* Pay - Site Reliability Engineer - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.