TweetFollow Us on Twitter

May 99 Online

Volume Number: 15 (1999)
Issue Number: 5
Column Tag: MacTech Online

May 99 Online

by Jeff Clites <online@mactech.com>

Longtime Mac users are experiencing a bit of culture shock in facing the reality that Apple's new OS family, Mac OS X Server and the soon-to-exist Mac OS X, is built on a Unix foundation.

Developers who come from a computer science background will surely be no strangers to Unix and its command line - I doubt that the Macintosh was even mentioned in any of their classes. But for those of us who got here via a different, pure-Macintosh route, it can be disorienting. After all, Unix was one of the unfriendly operating systems that Apple had in mind when they dubbed the Macintosh the computer for "the rest of us", right?

But after you get past the initial strangeness it begins to make a lot of sense. Unix can form a stable core upon which to build an OS. And if you continue to think in the usual metaphors, you can look at it this way: you probably don't want to build your house entirely out of concrete (it would be pretty bleak), but you certainly want to build it on top of a concrete foundation. So if everything goes as planned, when the consumer release of Mac OS X arrives, casual users will be no more aware of its Unix underpinnings than your guests are of the concrete walls in your cellar.

But what does it really mean that Mac OS X is "built upon a Unix core"? This month we are going to try to answer this question and find out a little bit more about the history and culture of Unix, and track down some sources to help developers find out what they need to know to feel comfortable with this new facet of Apple's OS.

A Brief History of BSD

Unix originated in the late 1960s at AT&T Bell Labs. Due to liberal academic licensing policies, universities began using Unix for teaching and research, leading to the development of BSD (the Berkeley Software Distribution) at UC Berkeley. AT&T continued to develop their own version, System V, and these two versions have formed the basis of nearly all subsequent Unix derivatives. BSD, owing to its academic heritage, tended to be more experimental and innovative, but much cross-pollination continued after the initial division. 4.4 BSD-Lite was the last version to be released by UC Berkeley (the "Lite" refers to this version's freedom from any AT&T copyrighted code). The main currently-active systems derived from BSD are NetBSD and OpenBSD, which are available for various hardware platforms, as well as the Intel-centric FreeBSD and the commercial BSDI. You can read more about the history and current state of BSD at the following URLs.

Knowledge Base - Do you have a brief synopsis of Unix history?
http://kb.indiana.edu/data/acve.html
Knowledge Base - What is BSD Unix and what are FreeBSD, NetBSD, OpenBSD and BSD/OS?
http://kb.indiana.edu/data/agom.html
[comp.unix.bsd] NetBSD, FreeBSD, and OpenBSD FAQs
http://faqs.colombianet.net/386bsd-faq/top.html
The return of BSD - SunWorld - January 1999
http://www.sunworld.com/swol-01-1999/swol-01-bsd.html
Nick Moffitt's $7 History of Unix
http://crackmonkey.org/unix.html

The Kernel

Mac OS X Server is based on the Mach kernel, originally developed at Carnegie Mellon University. The kernel provides only very basic services: processor scheduling, interprocess communication, and management of virtual memory. Mach is designed to be small; this makes it easy to understand (and therefore debug), as well as fast and efficient. (I forget who first pointed out that the only real way to speed up code is to make it do less). All other system services are provided by a server application (or a set of them). This is how it is possible for both Mac OS X Server and MkLinux to be based on the Mach kernel (albeit different version) - in a very real sense, Mach is the operating system, and Linux and BSD are applications. Although it's invisible to the programmer, what would have been a system call under the MacOS (or 4.4 BSD) is really an interprocess message under Mach. So these are the two senses in which Mac OS X Server is "based on" Unix: the Mach kernel has a Unix heritage, and 4.4 BSD-based application compile and run by virtue of the BSD "personality".

You can get the official scoop on Mach and its relation to Mac OS X Server in Apple's developer documentation. Carnegie Mellon also has a Mach site with a collection of technical information and publications. Of special interest is the introductory paper "Unix as an Application Program". Also be sure to check out the Linux Journal article "Linux? On the Macintosh? With Mach?", by Vicki Brown.

Apple's Mach Reference
http://developer.apple.com/techpubs/macosxserver/System/Documentation/Developer/OperatingSystem/Mach.pdf
CMU CS Project Mach Home Page
http://www.cs.cmu.edu/afs/cs.cmu.edu/project/mach/public/www/mach.html
Unix as an Application Program (in PostScript form)
ftp://ftp.cs.cmu.edu/project/mach/doc/published/mach3_intro.ps
Linux? On the Macintosh? With Mach?
http://www.linuxjournal.com/issue37/2093.html

Getting Oriented

I would imagine that most Macintosh programmers have no intention of writing Unix-style applications just because they can (at least I hope not), but nonetheless they want to be comfortable with the Unix side of Mac OS X Server. In this light, I recently began to peruse three books which cover the spectrum of topics about which you are likely to be curious.

As its title implies, The Unix Philosophy, by Mike Gancarz (ISBN 1-55558-123-4) explains the motivation and culture behind the design of Unix systems. It's a pleasant read - it's short and non-technical, focussing on ideology. For a user-level introduction, Unix: Clearly Explained by Richard L. Petersen (ISBN 0-12-552130-8) covers the basics, including pipes, the most common command-line tools, the various shells, and the vi and emacs text editors. These two books could be read in either order, depending on whether you like conceptual background before concrete "how-to", or vice-versa. One thing they don't cover is the Pico text editor, which Apple has included with their distribution. If you are forced to boot into single-user mode and fix something via the command-line interface, then you will find Pico more friendly in your time of crisis than vi or emacs. Fortunately, NC State University has a nice online Pico tutorial, and Indiana University has a convenient reference guide that you can download in pdf format. (And of course, there are always the man pages.)

PICO tutorial
http://www2.ncsu.edu/ncsu/cc/pub/tutorials/pico_tutor/pico_intro.html
The Pico text editor under Unix: A quick guide
http://www.indiana.edu/~ucspubs/b103/b103.pdf

At the other end of the spectrum is The Design and Implementation of the 4.4BSD Operating System (ISBN 0-201-54979-4). Written by the original system architects, it covers all of the technical details of the design of BSD and the algorithmic choices which underlie it. It isn't programmer's documentation per se (it doesn't teach you how to write Unix applications), but it will answer all of the architectural questions that the curious developer might ask. It's heavy reading, especially if you are new to Unix, but it's kind of comforting to have the book with all the answers.

These and a truck load of other links are available from the MacTech Online web pages at www.mactech.com/online/.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Apple Remote Desktop 3.8 - Remotely cont...
Apple Remote Desktop is the best way to manage the Mac computers on your network. Distribute software, provide real-time online help to end users, create detailed software and hardware reports, and... Read more
NeoOffice 2014.7 - Mac-tailored, OpenOff...
NeoOffice is a complete office suite for OS X. With NeoOffice, users can view, edit, and save OpenOffice documents, PDF files, and most Microsoft Word, Excel, and PowerPoint documents. NeoOffice 3.x... Read more
DesktopLyrics 2.6.6 - Displays current i...
DesktopLyrics is an application that displays the lyrics of the song currently playing in "iTunes" right on your desktop. The lyrics for the song have to be set in iTunes; DesktopLyrics does nothing... Read more
Ember 1.8.3 - Versatile digital scrapboo...
Ember (formerly LittleSnapper) is your digital scrapbook of things that inspire you: websites, photos, apps or other things. Just drag in images that you want to keep, organize them into relevant... Read more
Apple iTunes 12.1 - Manage your music, m...
Apple iTunes lets you organize and play digital music and video on your computer. It can automatically download new music, app, and book purchases across all your devices and computers. And it's a... Read more
LibreOffice 4.4.3 - Free, open-source of...
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
FoldersSynchronizer 4.2.1 - Synchronize...
FoldersSynchronizer is a popular and useful utility that synchronizes and backs-up files, folders, disks and boot disks. On each session you can apply special options like Timers, Multiple Folders,... Read more
Simon 4.0.2 - Monitor changes and crashe...
Simon monitors websites and alerts you of crashes and changes. Select pages to monitor, choose your alert options, and customize your settings. Simon does the rest. Keep a watchful eye on your... Read more
Cocktail 8.1.2 - General maintenance and...
Cocktail is a general purpose utility for OS X that lets you clean, repair and optimize your Mac. It is a powerful digital toolset that helps hundreds of thousands of Mac users around the world get... Read more
Cyberduck 4.6.4 - 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

Playworld Superheroes Review
Playworld Superheroes Review By Tre Lawrence on January 30th, 2015 Our Rating: :: HERO CRAFTINGUniversal App - Designed for iPhone and iPad It’s all about the imagination, fighting bad creatures — and looking good while doing so.   | Read more »
Join the SpongeBob Bubble Party in this...
Join the SpongeBob Bubble Party in this New Match 3 Bubble Poppin’ Frenzy Posted by Jessica Fisher on January 30th, 2015 [ permalink ] | Read more »
Handpick Review
Handpick Review By Jennifer Allen on January 30th, 2015 Our Rating: :: TANTALIZING SUGGESTIONSiPhone App - Designed for the iPhone, compatible with the iPad Handpick will make you hungry, as well as inspire you to cook something... | Read more »
Storm the Halls of Echo Base in First St...
Storm the Halls of Echo Base in First Star Wars: Galactic Defense Event Posted by Jessica Fisher on January 30th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Contradiction Review
Contradiction Review By Tre Lawrence on January 30th, 2015 Our Rating: :: SPOT THE LIEiPad Only App - Designed for the iPad Contradiction is a live action point and click adventure that’s pretty engaging.   Developer: Tim Follin... | Read more »
Unlock Sunshine Girl in Ironkill with th...
Unlock Sunshine Girl in Ironkill with this special 148Apps code Posted by Rob Rich on January 29th, 2015 [ permalink ] Robo-fighter Ironkill has been out on iOS a | Read more »
Crossroad Zombies Review
Crossroad Zombies Review By Jordan Minor on January 29th, 2015 Our Rating: :: CROSSWALKING DEADiPad Only App - Designed for the iPad Crossroad Zombies is a rough draft of a cool genre mash-up.   | Read more »
Blood Brothers 2 – Tips, Cheats, and Str...
War is hell: Is it the kind of hell you want to check out? Read our Blood Brothers 2 review to find out! Blood Brothers 2, DeNA’s follow-up to the original Blood Brothers, is an intriguing card collecting / role-playing / strategy hybrid. There’s... | Read more »
Blood Brothers 2 Review
Blood Brothers 2 Review By Nadia Oxford on January 29th, 2015 Our Rating: :: AN AGGRAVATING RELATIVEUniversal App - Designed for iPhone and iPad Blood Brothers 2 is built on a simple, solid foundation, but its free-to-play system... | Read more »
I AM BREAD, the Toast of the Town, is Ro...
Have you ever dreamt of being deliciously gluten-y? Do you feel passionate about Rye and Wheat? The guys at Bossa Studios do and that is why they are bringing I AM BREAD to iOS soon. The loafy app will feature all the new content that is being... | Read more »

Price Scanner via MacPrices.net

Intel Aims to Transform Workplace With 5th-Ge...
Intel Corporation today announced the availability of its 5th generation Intel Core vPro processor family that provides cutting-edge features to enable a new and rapidly shifting workplace. To meet... Read more
iOS App Sharalike Introduces New Instant Smar...
Sharalike slideshow and photo management software for iOS, is making it easier than ever to create shareable meaningful moments with its new instant SmartShow technology. Staying organized is a goal... Read more
Apple Becomes World’s Largest Smartphone Vend...
According to the latest research data from Strategy Analytics, as global smartphone shipments grew 31 percent annually to reach a record 380 million units in the fourth quarter of 2014. Apple became... Read more
Cut the Cord: OtterBox Resurgence Power Case...
Dead batteries and broken phones are two of the biggest issues for smartphone users today. Otterbox addresses both with the new Resurgence Power Case for Apple iPhone 6, promising to make those panic... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina MacBook Pros on sale for $200 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.6GHz/128GB Retina MacBook Pro: $1199.99 save $100 - 13″ 2.6GHz/... Read more
15-inch 2.5GHz Retina MacBook Pro on sale for...
 B&H Photo has the 15″ 2.5GHz Retina MacBook Pro on sale for $2319.99 including free shipping plus NY sales tax only. Their price is $180 off MSRP, and it’s the lowest price available for this... Read more
Back in stock: Refurbished iPod nanos for $99...
The Apple Store has Apple Certified Refurbished 16GB iPod nanos available for $99 including free shipping and Apple’s standard one-year warranty. That’s $50 off the cost of new nanos. Most colors are... Read more
Apple lowers price on refurbished 256GB MacBo...
The Apple Store has lowered prices on Apple Certified Refurbished 2014 MacBook Airs with 256GB SSDs, now available for up to $200 off the cost of new models. An Apple one-year warranty is included... Read more
New Good Management Suite Simplifies Enterpri...
Good Technology has announced the availability of the Good Management Suite, a comprehensive cross-platform solution for organizations getting started with mobile business initiatives. Built on the... 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

Jobs Board

At-Home Chat Specialist- *Apple* Online Stor...
**Job Summary** At Apple , we believe in hard work, a fun environment, and the kind of creativity and innovation that only comes about when talented people from diverse Read more
Sr. Mac Expert- *Apple* Online Store - Apple...
**Job Summary** The World Wide Apple Online Store (AOS) Sales and Service team is looking for motivated, outgoing, and tech savvy individuals who want to offer Apple 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
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
At-Home Chat Specialist- *Apple* Online Stor...
**Job Summary** At Apple , we believe in hard work, a fun environment, and the kind of creativity and innovation that only comes about when talented people from diverse Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.