TweetFollow Us on Twitter

Dec 93 Tips, Tidbits
Volume Number:9
Issue Number:12
Column Tag:Tips & Tidbits

Tips & Tidbits

By Neil Ticktin, Editor-in-Chief

This column is your opportunity to spread the word about little bits of information that you find out about. These tidbits can be programming related or they can be user tips that are particularly useful to programmers.

MacTech Magazine will pay $25 for every tip used, and $50 for the Tip of the Month. Or you can take your award in orders or subscriptions.

To submit a tip, send in a letter to the magazine. E-mail is our preferred method, but feel free to send something via the US Mail. See page two for all addresses. If you do send snail mail, enclose a printed copy and a disk copy of the letter so that it does not have to be retyped.

Tip of the Month: Accelerating MPW's Startup Sequence

This trick is described in the Examples folder that comes with MPW. But in talking to other users, I was surprised to find few people know about it, and even fewer use it.

When MPW is launched, it executes a script named “Startup,” which sets up environment variables, aliases, custom menus, and so forth. This can take from several seconds to over a minute.

It is easy to optimize this startup sequence. After launching MPW normally, copy the following lines into the MPW Worksheet window. Then highlight them as a block and press Enter:

/* 1 */

   Rename "{MPW}"Startup "{MPW}"Startup.Old
   Begin
      Set
      Export
      Alias
      AddMenu
   End > "{MPW}"Startup

This creates an optimized Startup script that will typically execute two to ten times faster than the original. The initial “Rename” command saves the original Startup script, so you can revert to it if you decide you don’t like the results. But if you do “before and after” timings, I think you’ll be happy with the speed improvement.

There are a couple of caveats though. First, the optimized Startup script is not organized and commented the same way the original is. If you frequently change your MPW configuration, you might find the optimized script harder to read and edit. Or you might find it to be easier; the point is that it is different.

Second, if you have UserStartup files that are often modified (such as UserStartup•RunMenu, described in MacTech Magazine, October, 1993), you may wish to add a line to the end of the optimized Startup script to forcibly execute the UserStartup commands. With UserStartup•RunMenu as an example, here’s what the command would look like:

        Execute "{PrefsFolder}"UserStartup•RunMenu

In doing this, you will cause some startup commands to be executed more than once (since some commands from the UserStartup will appear in the optimized Startup script as well). As a final “tweak,” you should then edit the optimized Startup script to delete any commands which will be carried out by forcibly executed UserStartup scripts.

- Lee David Rimar, Absoft Corporation

Strings that go both ways

When writing programs in C on the Macintosh, one thing that we need to deal with is the two possible formats of strings: C-style and Pascal-style. To save the repeated conversion time between the two formats, I sometimes use a format I call the two-in-one format that has both at once.

The C-style string uses a terminating zero character (null) at the end of the string to mark it’s length. The Pascal-style string uses a length byte as the first byte of the string (see figure). Both are allocated by allocating the space for the maximum number of characters the string will hold plus one for either the length byte or the termination byte. My two-in-one format uses both a length byte as it’s first byte and the zero byte as it’s last. To allocate this, take the data size and add two for both the Pascal-style length byte and the C-style terminator. The illustration shows how the length byte, string data, and terminator are laid out.

To use this as a Pascal string, simply use it normally. To use it as a C string, pass the string address as string + 1. Of course, if the size of the string is changed, then either the length byte or the terminator will need to adjusted. If you use calls that treat it as a C string, then the length byte will need adjusting. If you use Pascal-style calls, the terminator will need adjusting. The adjusting isn’t always as hard as you might think.

The following code fragment illustrates using the two-in-one string format:

/* 2 */

Str255  stringOne;
char  stringTwo[50];

...
/*   #1 Toolbox call uses Pascal-style string. */
GetIText (dialogItemHandle, stringOne);
stringOne[stringOne[0] + 1] = ’\0’;     // Add term. byte
...
/*   #2 Uses C-style string and returns the num. of characters. */
stringTwo[0] = sprintf (stringTwo + 1, “foobar”);
...
/*   #3 Two-in-one style, notice the length plus two. */
BlockMove (stringOne, stringTwo, stringOne[0] + 2);

In #1, the toolbox call returns a Pascal-style string, so, for the two-in-one format we’ve got to add the terminator. We know that stringOne[0] is the length byte and we know that stringOne[length] is the last byte of data in the string. So, the length plus one is the terminator byte.

In #2, we’re using the string as a C-style string. Notice that the C-style string starts at an offset of one, this avoids the Pascal-style length byte. Fortunately, sprintf returns the number of bytes (characters) written if there’s no error so we can use it to adjust the length byte. Other C library calls like printf, scanf and their derivatives also return the number of characters processed.

In #3, we’re using the Toolbox call BlockMove() to copy a two-in-one format string. Since the length is the length of the data, we’ve got to add two to allow for the length byte and the terminator byte.

I’ve found that judicious use of this string format can save a lot of conversion in string-heavy programs.

- Malcolm Teas

Step-step

In Think Pascal, the option key allows you to “step-step” through the code. Hold down the option key and pull down the RUN menu. You will see the step-step option. Step-step walks through your source code one line at a time, stepping into functions and procedures. It’s like a guided tour through your own program. Hold down the option key and browse through the Think Pascal menus. You may be surprised how much the option key modifies in the menus.

- Lillian Thompson, Reno, Nevada

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Adobe Premiere Pro CC 2015 9.0.1 - Digit...
Premiere Pro CC 2015 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous Premiere Pro customer). Premiere Pro CS6 is still available for... Read more
Adobe After Effects CC 2015 13.5.1 - Cre...
After Effects CC 2015 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous After Effects customer). After Effects CS6 is still available... Read more
Adobe Creative Cloud 2.2.0.129 - Access...
Adobe Creative Cloud costs $49.99/month (or less if you're a previous Creative Suite customer). Creative Suite 6 is still available for purchase (without a monthly plan) if you prefer. Introducing... Read more
Tower 2.2.3 - Version control with Git m...
Tower is a powerful Git client for OS X that makes using Git easy and more efficient. Users benefit from its elegant and comprehensive interface and a feature set that lets them enjoy the full power... Read more
Apple Java 2015-001 - For OS X 10.7, 10....
Apple Java for OS X 2015-001 installs the legacy Java 6 runtime for OS X 10.11 El Capitan, OS X 10.10 Yosemite, OS X 10.9 Mavericks, OS X 10.8 Mountain Lion, and OS X 10.7 Lion. This package is... Read more
Adobe Muse CC 2015 2015.0.1 - Design and...
Muse CC 2015 is available as part of Adobe Creative Cloud for as little as $14.99/month (or $9.99/month if you're a previous Muse customer). Muse CS6 is still available for purchase (without a... Read more
Adobe Illustrator CC 2015 19.1.0 - Profe...
Illustrator CC 2015 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous Illustrator customer). Illustrator CS6 is still available for... Read more
Corel Painter 14.1.0.1105 - Digital art...
Corel Painter helps you create astonishing art in a variety of media. Paint with vivid oil paints, fluid water colors, and earthy charcoals. Corel Painter flawlessly recreates the tones and textures... Read more
Pacifist 3.5.4 - Install individual file...
Pacifist opens up .pkg installer packages, .dmg disk images, .zip, .tar. tar.gz, .tar.bz2, .pax, and .xar archives and more, and lets you extract or install individual files out of them. This is... Read more
Dropbox 3.8.4 - Cloud backup and synchro...
Dropbox is an application that creates a special Finder folder that automatically syncs online and between your computers. It allows you to both backup files and keep them up-to-date between systems... Read more

Mazes of Karradash (Games)
Mazes of Karradash 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: The city of Karradash is under attack: the monsters of the Shadow Realms are emerging from the depths.No adventurer is... | Read more »
Battle Golf is the Newest Game from the...
Wrassling was a pretty weird - and equally great - little wressling game. Now the developers, Folmer Kelly and Colin Lane, have turned their attention to a different sport: golfing. This is gonna be weird. [Read more] | Read more »
Qbert Rebooted has the App Store Going...
The weird little orange... whatever... is back, mostly thanks to that movie which shall remain nameless (you know the one). But anyway it's been "rebooted" and now you can play the fancy-looking Qbert Rebooted on iOS devices. [Read more] | Read more »
Giant Monsters Run Amok in The Sandbox...
So The Sandbox has just hit version number 1.99987 (seriously), and it's added a lot more stuff. Just like every other update, really. [Read more] | Read more »
Fish Pond Park (Games)
Fish Pond Park 1.0.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.0 (iTunes) Description: Nurture an idyllic slice of tourist's heaven into the top nature spot of the nation, furnishing it with a variety of... | Read more »
Look after Baby Buddy on your Apple Watc...
Parigami Gold is the new premium version of the match three puzzler that includes Apple Watch support and all new content. You won't simply be sliding tiles around on your wrist, the Apple Watch companion app is an all new mini-game in itself. You'... | Read more »
Swallow all of your opponents as the big...
Eat all of the opposition and become the largest ball in Battle of Balls now available in the App Store and Google Play. Battle of Balls pits you against other opponents in real time and challenges you to eat more balls and grow larger than all of... | Read more »
PAC-MAN Championship Edition DX (Games)
PAC-MAN Championship Edition DX 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: It’s Your World. EAT IT! Get ready for more ghost chain gobbling and frantic action in PAC-MAN® CE-DX! The... | Read more »
incurve (Games)
incurve 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: Get ready for 2 different gravities Goal is to hit as many white dots on your way up.When you're touching the screen, the dots have a... | Read more »
Crossy Road has its Own Merch Store Now....
Do you like Crossy Road? I mean do you really like Crossy Road? Well then you're in luck! Hipster Whale has opened up a Crossy Road store, so you can show off your fandom via official T-shirts. [Read more] | Read more »

Price Scanner via MacPrices.net

Sale! 13″ 1.6GHz/256GB MacBook Air for $1099,...
B&H Photo has the 13″ 1.6GHz/256GB MacBook Air on sale for $1099 including free shipping plus NY tax only. Their price is $100 off MSRP, and it’s the lowest price available for this model. Read more
iPad mini 4 To Be Upgraded To iPad Air 2 Spec...
There’s a certain inevitability about making Apple product predictions this time of year. Come September, we can pretty reliably count on the release of refreshed iPhones, along with the iOS 9... 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
13-inch 2.5GHz MacBook Pro on sale for $899,...
Best Buy has the 13″ 2.5GHz MacBook Pro available for $899.99 on their online store. Choose free shipping or free instant local store pickup (if available). Their price is $200 off MSRP. Price is... Read more
21-inch 2.9GHz iMac on sale for $1299, save $...
Best Buy has the 21″ 2.9GHz iMac on sale today for $1299.99 on their online store. Choose free shipping or free local store pickup (if available). Their price is $200 off MSRP, and it’s the lowest... Read more
Free Image Sizer 1.3 for iOS Offers Photo Edi...
Xi’An, China based G-Power has announced the release of Image Sizer 1.3 for the iPhone, iPad, and iPod touch, an important update to their free photo editing app. Image Sizer’s collection of easy to... Read more
Sale! 13″ 1.6GHz/128GB MacBook Air for $899,...
B&H Photo has the 13″ 1.6GHz/128GB MacBook Air on sale for $899 including free shipping plus NY tax only. Their price is $100 off MSRP, and it’s the lowest price available for this model. Read more
13-inch Retina MacBook Pros on sale for $100...
Best Buy has 13-inch Retina MacBook Pros on sale for $100 off MSRP on their online store. Choose free shipping or free local store pickup (if available). Prices are for online orders only, in-store... Read more
Will BMW’s i3 Electric Vehicle Be The Automo...
The German-language business journal Manager Magazin’s Michael Freitag reports that Apple and the German performance/luxury automaker Bayerishe Motoren Werke (BMW) are back at far-reaching... Read more
Sale! $250 off 15-inch Retina MacBook Pro, $2...
B&H Photo has lowered their price for the 15″ 2.2GHz Retina MacBook Pro to $1749, or $250 off MSRP. Shipping is free, and B&H charges NY sales tax only. They have the 27″ 3.3GHz 5K iMac on... Read more

Jobs Board

*Apple* Customer Experience (ACE) Leader - A...
…management to deliver on business objectives Training partner store staff on Apple products, services, and merchandising guidelines Coaching partner store staff on Read more
Project Manager - *Apple* Pay Security - Ap...
**Job Summary** The Apple Pay Security team is seeking a highly organized, results-driven Project Manager to drive the development of Apple Pay Security. If you are Read more
*Apple* TV Product Design Internship (Spring...
…the mechanical design effort associated with creating world-class products with the Apple TV PD Group. Responsibilities will include working closely with manufacturing, Read more
*Apple* Watch SW Application Project Manager...
**Job Summary** The Apple Watch software team is looking for an Application Engineering Project Manager to work on new projects for Apple . The successful candidate 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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.