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

 
AAPL
$113.11
Apple Inc.
+1.33
MSFT
$47.89
Microsoft Corpora
+0.23
GOOG
$520.04
Google Inc.
+3.69

MacTech Search:
Community Search:

Software Updates via MacUpdate

NeoOffice 2014.6 - 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
LibreOffice 4.3.5.2 - 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
CleanApp 5.0.0 Beta 5 - Application dein...
CleanApp is an application deinstaller and archiver.... Your hard drive gets fuller day by day, but do you know why? CleanApp 5 provides you with insights how to reclaim disk space. There are... Read more
Monolingual 1.6.2 - Remove unwanted OS X...
Monolingual is a program for removing unnecesary language resources from OS X, in order to reclaim several hundred megabytes of disk space. It requires a 64-bit capable Intel-based Mac and at least... Read more
NetShade 6.1 - Browse privately using an...
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
calibre 2.13 - Complete e-library manage...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
Mellel 3.3.7 - Powerful word processor w...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
ScreenFlow 5.0.1 - Create screen recordi...
Save 10% with the exclusive MacUpdate coupon code: AFMacUpdate10 Buy now! ScreenFlow is powerful, easy-to-use screencasting software for the Mac. With ScreenFlow you can record the contents of your... Read more
Simon 4.0 - Monitor changes and crashes...
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
BBEdit 11.0.2 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more

Latest Forum Discussions

See All

Crossbow Warrior – The Legend of William...
Crossbow Warrior – The Legend of William Tell Review By Lee Hamlet on December 22nd, 2014 Our Rating: :: MISSES THE MARKUniversal App - Designed for iPhone and iPad Crossbow Warrior details the entertaining adventures of legendary... | Read more »
Workflow: Powerful Automation Made Simpl...
Workflow: Powerful Automation Made Simple Review By Campbell Bird on December 22nd, 2014 Our Rating: :: GO WITH THE FLOWUniversal App - Designed for iPhone and iPad This powerful app lets users accomplish multiple tasks at touch of... | Read more »
My Little Monster Review
My Little Monster Review By Jordan Minor on December 22nd, 2014 Our Rating: :: IT'S ALIVE!Universal App - Designed for iPhone and iPad What’s it worth to make your own monster?   | Read more »
Galaxy Trucker Pocket (Games)
Galaxy Trucker Pocket 1.0.8 Device: iOS iPhone Category: Games Price: $2.99, Version: 1.0.8 (iTunes) Description: Galaxy Truckers Wanted!================================================================= (5/5) "Galaxy Trucker isn’t... | Read more »
Make your own Tribez Figures (and More)...
Make your own Tribez Figures (and More) with Toyze Posted by Jessica Fisher on December 19th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
So Many Holiday iOS Sales Oh My Goodness...
The holiday season is in full-swing, which means a whole lot of iOS apps and games are going on sale. A bunch already have, in fact. Naturally this means we’re putting together a hand-picked list of the best discounts and sales we can find in order... | Read more »
It’s Bird vs. Bird in the New PvP Mode f...
It’s Bird vs. Bird in the New PvP Mode for Angry Birds Epic Posted by Jessica Fisher on December 19th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Telltale Games and Mojang Announce Minec...
Telltale Games and Mojang Announce Minecraft: Story Mode – A Telltale Games Series Posted by Jessica Fisher on December 19th, 2014 [ permalink ] | Read more »
WarChest and Splash Damage Annouce Their...
WarChest and Splash Damage Annouce Their New Game: Tempo Posted by Jessica Fisher on December 19th, 2014 [ permalink ] WarChest Ltd and Splash Damage Ltd are teaming up again to work | Read more »
BulkyPix Celebrates its 6th Anniversary...
BulkyPix Celebrates its 6th Anniversary with a Bunch of Free Games Posted by Jessica Fisher on December 19th, 2014 [ permalink ] BulkyPix has | Read more »

Price Scanner via MacPrices.net

Apple resellers offer free overnight shipping
The Apple Store is now offering free next-day shipping on all in stock items if ordered before 12/23/14 at 10:00am PT. Local store pickup is also available within an hour of ordering for any in stock... Read more
Holiday sale continues: 15-inch Retina MacBoo...
 B&H Photo has the new 2014 15″ Retina MacBook Pros on sale for up to $300 off MSRP for a limited time. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.2GHz Retina MacBook Pro: $... Read more
Holiday sale: 13-inch 128GB MacBook Air for $...
 Best Buy has the 2014 13-inch 1.4GHz 128GB MacBook Air on sale for $849.99, or $150 off MSRP, on their online store. Choose free home shipping or free local store pickup (if available). Price valid... Read more
13-inch 2.6GHz Retina MacBook Pro on sale for...
Best Buy has lowered their price on the 2014 13″ 2.6GHz/128GB Retina MacBook Pro to $1149.99 on their online store for a limited time. That’s $150 off MSRP and the lowest price available for this... Read more
Kodak Returns to CES With New Consumer Produ...
Former photography colossus Kodak is returning to CES for the first time in three years where the Kodak booth (#21818 South Hall 1) will showcase a wide range of innovative, imaging-related products... Read more
Invaluable Launches New Eponymously -Named A...
Invaluable, the world’s largest online live auction marketplace, hhas announced the official launch of the Invaluable app for iPad, now available for download in the iTunes App Store. Invaluable... Read more
IDC Reveals Worldwide Mobile Enterprise Appli...
International Data Corporation (IDC) last week hosted the IDC FutureScape: Worldwide Mobile Enterprise Applications and Solutions 2015 Predictions Web conference. The session provided organizations... Read more
Hello Vino Wine App Launches “Safe Ride Home”...
Hello Vino has announced addition of a new “Get a Safe Ride Home” feature in its Food & Drink app with a direct connection to Uber, the technology platform that connects users with rides. The... Read more
DEVON-technologies Releases DEVONthink To Go...
Coeur d’Alene, Idaho based DEVON-technologies, LLC has updated DEVONthink To Go, its mobile companion to DEVONthink, to version 1.5. The update includes an iOS 8 extension, compatibility with the... Read more
The Apple Store offering free next-day shippi...
The Apple Store is now offering free next-day shipping on all in stock items if ordered before 12/23/14 at 10:00am PT. Local store pickup is also available within an hour of ordering for any in stock... Read more

Jobs Board

*Apple* Store Leader Program (US) - Apple, I...
…Summary Learn and grow as you explore the art of leadership at the Apple Store. You'll master our retail business inside and out through training, hands-on experience, Read more
Project Manager, *Apple* Financial Services...
**Job Summary** Apple Financial Services (AFS) offers consumers, businesses and educational institutions ways to finance Apple purchases. We work with national and 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...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.