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

Paparazzi! 1.0b7 - Make user-defined siz...
Paparazzi! is a small utility for OS X that makes screenshots of webpages. This very simple tool takes screenshots of websites which do not fit on one screen. You specify the desired width, minimal... Read more
Amadeus Pro 2.4.4 - Multitrack sound rec...
Amadeus Pro lets you use your Mac for any audio-related task, such as live audio recording, digitizing tapes and records, converting between a variety of sound formats, etc. Thanks to its outstanding... Read more
Google Chrome 63.0.3239.108 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more
Apple Configurator 2.6 - Configure and d...
Apple Configurator makes it easy to deploy iPad, iPhone, iPod touch, and Apple TV devices in your school or business. Use Apple Configurator to quickly configure large numbers of devices connected to... Read more
WhatRoute 2.0.26 - Geographically trace...
WhatRoute is designed to find the names of all the routers an IP packet passes through on its way from your Mac to a destination host. It also measures the round-trip time from your Mac to the router... Read more
Remotix 5.0.4 - Access all your computer...
Remotix is a fast and powerful application to easily access multiple Macs (and PCs) from your own Mac. Features Complete Apple Screen Sharing support - including Mac OS X login, clipboard... Read more
WhatRoute 2.0.26 - Geographically trace...
WhatRoute is designed to find the names of all the routers an IP packet passes through on its way from your Mac to a destination host. It also measures the round-trip time from your Mac to the router... Read more
Google Chrome 63.0.3239.108 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more
Paparazzi! 1.0b7 - Make user-defined siz...
Paparazzi! is a small utility for OS X that makes screenshots of webpages. This very simple tool takes screenshots of websites which do not fit on one screen. You specify the desired width, minimal... Read more
Remotix 5.0.4 - Access all your computer...
Remotix is a fast and powerful application to easily access multiple Macs (and PCs) from your own Mac. Features Complete Apple Screen Sharing support - including Mac OS X login, clipboard... Read more

Latest Forum Discussions

See All

WWE Mayhem guide - beginner tips and tri...
WWE Mayhem brings all of the familiar faces from your favorite wrestling league to mobile in this exciting new fighting game. Build up a team of your favorite WWE superstars and fight your way to the championship title, or battle against your... | Read more »
The best new games we played this week -...
We've made it through another week, so let's treat ourselves to some of the best new games to launch in the past few days. It was another exciting week with some long-awaited indie games making their debut, and some big console titles making the... | Read more »
Match blocks to pull off dance moves in...
Ferdinand: Unstoppabull is a brand new match three puzzler based on the animated movie of (almost) the same name. As you can expect, you have to match blocks together to complete a bunch of puzzling levels and earn a high score. [Read more] | Read more »
Lineage 2: Revolution’s end of year upda...
Now available in 54 countries worldwide, Lineage 2: Revolution is continuing its global quest to be the most popular mobile MMORPG by launching a jam-packed end of year update. Complete with many subtle tweaks to help improve users’ online... | Read more »
The 5 best Star Wars games on iOS
The time has almost come.Star Wars: The Last Jedifinally hits theaters in the cinematic event that might be bigger than Christmas. To celebrate, we're taking a look at the best--and only the best--Star Warsmobile games to date. [Read more] | Read more »
Life Is Strange (Games)
Life Is Strange 1.1 Device: iOS Universal Category: Games Price: $2.99, Version: 1.1 (iTunes) Description: Life Is Strange is a five part episodic game that sets out to revolutionize story-based choice and consequence games by... | Read more »
Oddworld: New 'n' Tasty (Game...
Oddworld: New 'n' Tasty 1.0 Device: iOS Universal Category: Games Price: $7.99, Version: 1.0 (iTunes) Description: ** PLEASE NOTE: Requires 3.6GB free space to install. Runs at variable resolutions based on device capabilities.... | Read more »
Gorogoa (Games)
Gorogoa 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Gorogoa is an elegant evolution of the puzzle genre, told through a beautifully hand-drawn story designed and illustrated by Jason... | Read more »
Why Guns of Boom will be big for mobile...
Earlier this week, Game Insight, the minds that brought you Guns of Boom, revealed plans for an esports mode in the popular FPS title, with big implications for the game's future. Guns of Boom has been quite popular for some time now, so it's... | Read more »
The best mobile games to play on lazy ho...
With the holidays in full swing, there's hopefully going to be a lot of time off work lazing around the house. With all of that free time, it's a perfect opportunity to catch up on some mobile games that you might have missed out on earlier this... | Read more »

Price Scanner via MacPrices.net

Updated Price Trackers: Macs, iPads, iPhones,...
Scan our Apple Price Trackers for the latest information on sales, bundles, and availability on systems from Apple’s authorized internet/catalog resellers. We update the trackers continuously: – 15″... Read more
How to preorder a new iMac Pro and pay zero s...
B&H Photo and Adorama are accepting preorders on multiple configurations of the new Apple iMac Pro. Both resellers charge sales tax for residents of NY & NJ only, and shipping is free.... Read more
Apple Macs back in stock at Amazon with model...
Amazon has MacBook Pros, MacBook Airs, MacBooks, and iMacs on sale for up to $200 off MSRP as part of their Holiday/Christmas sale. Shipping is free. Note that stock of some Macs may come and go (and... Read more
Apple offering free overnight delivery on all...
Apple is now offering free overnight delivery on all in stock products until 3pm local time on December 22nd. This includes new as well as refurbished computers. Click here for more information. Read more
Beats Holiday sale at B&H, headphones and...
B&H Photo has Beats by Dr. Dre headphones, earphones, and speakers on sale for up to $80 off MSRP as part of their Holiday sale. Expedited shipping is free, and B&H charges sales tax to NY... Read more
Holiday sale: Apple resellers offer 2017 15″...
MacMall has 15″ MacBook Pros on sale for $220-$300 off MSRP, each including free shipping: – 15″ 2.8GHz MacBook Pro Space Gray (MPTR2LL/A): $2179, $220 off MSRP – 15″ 2.8GHz MacBook Pro Silver (... Read more
Holiday sale: Apple resellers offer 13″ MacBo...
B&H Photo has 13″ MacBook Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13-inch 2.3GHz/128GB Space Gray MacBook Pro (... Read more
Apple Watch Series 2, Certified Refurbished,...
Apple has Certified Refurbished Apple Watch Nike+ Series 2s, 42mm Space Gray Aluminum Case with Anthracite/Black Nike Sport Bands, available for $249 (38mm) or $279 (42mm). The 38mm model was out of... Read more
Apple offers Certified Refurbished 2016 12″ R...
Apple has Certified Refurbished 2016 12″ Retina MacBooks available starting at $949. Apple will include a standard one-year warranty with each MacBook, and shipping is free. The following... Read more
B&H drops price on 13″ 256GB MacBook Air...
B&H has the 13″ 1.8GHz/256GB Apple MacBook Air (MQD42LL/A) now on sale for $1079 including free shipping plus NY & NJ sales tax only. Their price is $120 off MSRP, and it’s the lowest price... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Payments Counsel, *Apple* Pay (payments, cr...
# Payments Counsel, Apple Pay (payments, credit/debit) Job Number: 112941729 Santa Clara Valley, California, United States Posted: 13-Dec-2017 Weekly Hours: 40.00 Read more
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 113124408 Waterford, CT, Connecticut, United States Posted: 17-Oct-2017 Weekly Hours: 40.00 **Job Summary** Are you Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.