TweetFollow Us on Twitter

Nov 95 Tips
Volume Number:11
Issue Number:11
Column Tag:Tips & Tidbits

Tips & Tidbits

By Steve Sisak, Contributing Editor

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

TIP OF THE MONTH

Two Screen MacsBug

One feature of MacsBug that I like is the "swap" command, which lets you leave a second monitor display the debugger (and punches it out of the desktop).

Then, if each DebugStr() ends in ";g" you will get an onscreen log of the last 10 or 15 breaks. I used this to track an elusive bug that would freeze my Mac and trash Macsbug memory... I could see which breakpoint went last.

Matt Slot

Informant in the Menu Bar

I do drivers, and you just plain can’t set a breakpoint in ADB completion routines (freezes the keyboard so MacsBug is worthless!).

So I throw one of the routines below into the routine to see when a piece of code gets executed.

What does it do? It "lights up" a bar (length dependant on screen resolution) in the menu bar. So if you DotToggle(300); you get a flashing short line in the menu bar.

[Leave this out of production code! Beware of using this on 24 bit color screens. Make sure that the value of where will not cause anything to be written into the alpha channel. Your best bet is to test with the screen that’s only 8 bits deep. -sgs]

void DotOn(long where) {
   long  *dot;
   dot = (long *)(LMGetScrnBase() + where);
   *dot |= -1;
}
void DotOff(long where) {
   long  *dot;
   dot = (long *)(LMGetScrnBase() + where);
   *dot &= 0;
}
void DotToggle(long where) {
   long  *dot;
   dot = (long *)(LMGetScrnBase() + where);
   *dot ^= -1;
}

Dave Fleck

Informative Cursors

One technique that I have used in the past where dropping into the debugger wasn't an option, and logging wasn't getting flushed in time/took too long, was to create a bunch of cursors numbering 00 - 99, and made a call to set the cursor and return the number of the previous cursor:

routine1()
{
short oldCursor = setDebugCursor(15);
    ...
    (void) setDebugCursor(oldCursor);
}

This way when the machine froze, the cursor would tell me what routine it had frozen in.

Tom Kimpton

MPW Editor Primitives

The MPW Command Reference describes 32 editor primitives which may be attached to any key sequence using the SetKey command. While the SetKey command itself is useful, the list of editor primitives alone is useful to MPW script writers.

Though only documented for use with SetKey, editor primitives may be used like any other MPW command: in scripts, command aliases, or AddMenu items. There are a couple of advantages:

1) They only work on the active window and have sharply defined functions, you don’t have to remember any selection expressions or argument lists. Compare:

 MoveStartOfFile

with

       Find • "{Active}"

2) They’re fast. I haven’t put a stopwatch to it, but you can see the difference immediately in running a script that uses the primitives and one that doesn’t.

The MPW Command reference lists these 32 primitives, the names of which should be self-explanatory:

DeleteCharLeft

DeleteCharRight

DeleteEndOfFile

DeleteEndOfLine

DeleteStartOfFile

DeleteStartOfLine

DeleteWordLeft

DeleteWordRight

MoveCharLeft

MoveCharRight

MoveEndOfLine

MoveLineDown

MoveLineUp

MovePageDown

MovePageUp

MoveStartOfFile

MoveStartOfLine

MoveWordLeft

MoveWordRight

SelectCharLeft

SelectCharRight

SelectEndOfFile

SelectEndOfLine

SelectLineDown

SelectLineUP

SelectPageDown

SelectPageUp

SelectStartOfFile

SelectStartOfLine

SelectWordLeft

SelectWordRight

There are also at least five primitives that aren’t in the command reference:

ScrollEnd

ScrollHome

ScrollPageDn

ScrollPageUp

DebuggerCommand

I can understand why Apple might not want users to casually drop into MacsBug from an MPW script, but I wonder why they chose not to document the scrolling commands? Whatever the reason, you should obviously use caution when playing with undocumented features.

Lee David Rimar
Absoft Corporation

Once Bitten Twice Shy

HGetState does not return a valid handle state when you pass it an empty handle (one whose master pointer is NULL). Instead, it returns an error code, so before you call HGetState, be sure to check that the handle isn’t empty and execute an alternate code path if it is.

I was bitten by this because I was using HGetState to determine if a handle was to a resource, and the resourced had been purged, so HGetStaate returned an error code instead of the handle flags and I incorrectly thought the handle wasn’t to a resource.

This is documented in Inside Macintosh, Memory, p. 1-61, but it bears some repeating. Remember to check the error values returned by the toolbox calls.

Eric Schlegel

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Macs Fan Control 1.5.14 - Monitor and co...
Macs Fan Control allows you to monitor and control almost any aspect of your computer's fans, with support for controlling fan speed, temperature sensors pane, menu-bar icon, and autostart with... Read more
VueScan 9.7.96 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
FileMaker Pro 19.6.1 - Quickly build cus...
FileMaker Pro is the tool you use to create a custom app. You also use FileMaker Pro to access your app on a computer. Start by importing data from a spreadsheet or using a built-in Starter app to... Read more
Duet 3.1.0.0 - Use your iPad as an exter...
Duet is the first app that allows you to use your iDevice as an extra display for your Mac using the Lightning or 30-pin cable. Note: This app requires a iOS companion app. Release notes were... Read more
Firefox 107.0.1 - Fast, safe Web browser...
Firefox 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 casual... Read more
War Thunder 2.21.1.91 - Multiplayer war...
In War Thunder, aircraft, attack helicopters, ground forces and naval ships collaborate in realistic competitive battles. You can choose from over 1,500 vehicles and an extensive variety of combat... Read more
Numbers 12.2.1 - Apple's spreadshee...
With Apple Numbers, sophisticated spreadsheets are just the start. The whole sheet is your canvas. Just add dramatic interactive charts, tables, and images that paint a revealing picture of your data... Read more
DEVONthink Pro 3.8.7 - Knowledge base, i...
DEVONthink is DEVONtechnologies' document and information management solution. It supports a large variety of file formats and stores them in a database enhanced by artificial intelligence (AI). Many... Read more
Drive Genius 6.2.3 - $79.00
Drive Genius features a comprehensive Malware Scan. Automate your malware protection. Protect your investment from any threat. The Malware Scan is part of the automated DrivePulse utility. DrivePulse... Read more
VLC Media Player 3.0.18 - Popular multim...
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

Latest Forum Discussions

See All

‘Genshin Impact’ Version 3.3 Pre-Install...
Following the reveal of the release date and more for Genshin Impact (Free) version 3.3 ‘All Senses Clear, All Existence Void’, HoYoverse showcased the Genius Invokation TCG that arrives this week in the update. | Read more »
TouchArcade Game of the Week: ‘Sling Min...
The world of PC games has always blown my mind because there’s just SO MUCH stuff out there that it’s not uncommon at all for there to be a game that’s well-liked and well-reviewed, and seemingly quite popular with a solid fanbase, and have it be... | Read more »
SwitchArcade Round-Up: Reviews Featuring...
Hello gentle readers, and welcome to the SwitchArcade Round-Up for December 2nd, 2022. So, today turned out a little quieter than the usual Friday. It was so quiet, in fact, that I decided to pen a few reviews. The Knight Witch, Railbound, and Donut... | Read more »
Blue Archive reveals its latest event st...
Nexon has announced the new update for Blue Archive, under the name of An Unconcealed Heart. Featuring a battle between two academies, the story will follow a group struggling to gain recognition, and will bring three new students to recruit. [... | Read more »
Dead Cells+ Is Out Now on Apple Arcade a...
Following the major update for Dead Cells on iOS and Android a few days ago, Playdigious has brought Dead Cells+ () to Apple Arcade. As an App Store Great, Dead Cells+ includes all prior paid DLC and content updates. It also has exclusive mobile... | Read more »
SwitchArcade Round-Up: ‘Romancing SaGa’,...
Hello gentle readers, and welcome to the SwitchArcade Round-Up for December 1st, 2022. Wow, December. We’re already at the last month of the year? Phew. I have a lot of work to finish in the next few weeks. As for today, we’ve got a little news, a... | Read more »
‘Railbound’ Update Now Available Adding...
One of our favorite puzzlers released this year is Railbound from Afterburn Games, which hit in early September and earned our Game of the Week recognition for being an absolutely ace logic puzzler. The goal is to place rail pieces down in order to... | Read more »
The Seven Deadly Sins: Grand Cross celeb...
Netmarble Corporation has pulled out all the stops to celebrate the 3 and a half year anniversary of The Seven Deadly Sins: Grand Cross. The Grand Cross 3.5th Year Anniversary the Ultimate One, a rather wordy title, brings with it a brand new... | Read more »
‘Skullgirls Mobile’ Major Update 5.2 Out...
Developer Hidden Variable pushed out a major update for Skullgirls Mobile (Free) a few hours ago. The version 5.2 update brings in Black Dahlia (before the console and PC game), Retakes, XP Treats, free gifts, and more. Since launch, Skullgirls... | Read more »
Out Now: ‘Disgaea 4’, ‘Romancing SaGa: M...
Each and every day new mobile games are hitting the App Store, and so each week we put together a big old list of all the best new releases of the past seven days. Back in the day the App Store would showcase the same games for a week, and then... | Read more »

Price Scanner via MacPrices.net

Holiday Sale: Apple AirPods Pro for only $199...
Amazon has new 2022 AirPods Pro in stock and on sale for $199.99 shipped as part of their Holiday sale. Their price is $50 off Apple’s MSRP, equaling their Black Friday price, and it’s the lowest... Read more
New Holiday Sale: Apple retailers are offerin...
Several Apple retailers lowered prices on 10.9″ iPad Airs overnight to lows of $100 off MSRP starting at $499. Their prices are the lowest available for iPad Airs anywhere this Holiday season right... Read more
New Holiday sale at Amazon: Take $50 off Appl...
Amazon has Apple’s new 10th-generation iPads in stock and on sale, for the first time, for $50 off MSRP starting at only $399. Their discount applies to all models and all colors. With the discount,... Read more
Holiday Sale: Get an 8.3″ Apple iPad mini for...
Sams Club has 10.9″ 64GB iPad minis on Holiday sale for $80-$100 off MSRP through December 7, 2022. With their discount, prices start at $399 — the cheapest price for a new iPad mini from any of the... Read more
Sams Club Holiday December Event sale: Apple...
Apple AirPods Max headphones are on sale at Sams Club for $110 off MSRP ($439) as part of their December Event sale, ending on December 7, 2022, valid for all colors. Sale price for online orders... Read more
Apple’s 10.2″ 64GB 9th-generation iPads are o...
Sams Club has 9th-generation 64GB iPads on Holiday sale for $60 off MSRP through December 7, 2022. With their discount, prices start at $259 — the cheapest price for a new iPad from any of the Apple... Read more
11″ 128GB WiFi M2 iPad Pro on sale for $749,...
B&H Photo has the new 11″ 128GB WiFi M2-powered iPad Pro (in Space Gray or Silver) on Holiday sale for $749 including free 1-2 day shipping to most US addresses. Their price is $50 off MSRP and... Read more
Find the best Holiday sale price on an iPad u...
We’ve updated our iPad Price Trackers with the latest information on the new 10th-generation iPads, M2-powered iPad Pros, M1 iPad Airs, iPad minis, and 9th generation iPads from Apple’s authorized... Read more
Apple retailers are offering $100-$150 Holida...
Apple retailers have posted their most-recent Holiday sale prices on 13″ MacBook Airs. Take up to $150 off MSRP on M2-powered Airs with these sales with prices starting at only $1099. Free shipping... Read more
Holiday Sale: Apple’s 14″ MacBook Pros with M...
B&H Photo is offering $200-$300 discounts on Apple’s 14″ MacBook Pros with M1 Pro CPUs as part of their Holiday 2022 sale, with prices starting at $1799. Free 1-2 day shipping is available to... Read more

Jobs Board

Support Technician II - *Apple* Support - O...
…problems and acting as a liaison between customers and resolving groups. As an Apple Technical Specialist, you will be supporting many of our popular Apple Read more
*Apple* Electronic Repair Technician - PlanI...
…a highly motivated individual to join our Production Department as an Apple Electronic Repair Technician. The computer repair technician will diagnose, assemble, Read more
Lead Developer - *Apple* tvOS - Rumble (Uni...
…earnings, and positive sentiment About the role: We are looking for a Lead Apple tvOS Developer to join our application engineering team to expand our video centric Read more
Tier 1 Endpoint Engineer - *Apple* - Red Ri...
…Desk on site, at our Client's location, with a focus on support to Apple products. This position will handle technical support requests directly from customers and Read more
Product Manager II - *Apple* - DISH (United...
…you will be doing We seek an ambitious, data-driven thinker to assist the Apple Product Development team as our new Retail Wireless division continues to grow and Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.