TweetFollow Us on Twitter

Aug 93 Tips, Tidbits
Volume Number:9
Issue Number:8
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

If you log a MacsBug disassembly to a file the instructions are saved in the form:

     +0000  40809A7C   MOVEC    CACR,D1  | 4E7A 1002
     +0004  40809A80   ADDQ.W   #$8,D1   | 5041

One day I got sick of editing disassembled code, especially the code I wanted to recompile later. I wrote an MPW script to edit MacsBug disassembly log file into code that is easy to read and recompile, like this:

 MOVEC  CACR,D1
 ADDQ.W #$8,D1

Here is the script to do this. For those of you who don't know, the "#" character indicates a comment to be ignored by MPW.

#STEP1
format -f geneva -s 9 -t 26 #Set font, font size, tab size
find •  #Go to beginning of file
Loop    #Execute lines within loop repeatedly

 # Next line makes a selection of: spaces that are followed 
 # by a "+" all text between that and the next several 
 # spaces, And all text between the previous two and the next 
 # several spaces. Selects everything in front of the Opcode 
 # (MOVEC). Example - Selection between "" 
 # "  +0000 40809A7C "MOVEC CACR,D1 | 4E7A 1002
find  /" "++/:/" "+/:/" "+/
replace § "t"   #Replace the selection with a tab
find /" "+/ #Select the spaces after the Opcode
replace § "t"   #Replace the selection with a tab
find /" "+/:/ /  #Selection starts after the Operand 
 #(CACR,D1) and ends at the end of the line
replace § ""#Replace above selection with nothing
End#Loop if not at the end of the file

#STEP 2 - Clean up all RTS instructions
find •
Loop    #Loop until end of file reached
find /RTS/#Find an "RTS" string
find /t/:/ /    #Select all text after "RTS" to end of line
replace § ""#Replace with nothing
End

Execute STEP1 and STEP2 separately! In MPW, make the window that contains your disassemble routine the target window - click on it and then click back to the window that contains the above script. Select the lines following STEP1 and hit the "Enter" key. Then select STEP2 and hit Enter again. Your code should nicely align into the format shown above. The formatted code needs little editing before it can be recompiled.

- Greg Pribyl

Incline Village, Nevada

An Anonymouse Tip

According to Inside Macintosh Volume VI, the Macintosh File Manager is fully implemented in A/UX. This may be true when accessing Macintosh volumes. However, if you are writing to a Unix partition there is a subtle difference in behavior which can cause headaches.

If you set the logical end-of-file to zero, using a call such as "PBSetEOF", you might assume that the file position would automatically be set to zero as well, so that if you subsequently write to the file the data will be written starting at the zero position. This is in fact what happens if the file is on a Mac volume.

However, if it's on a UNIX volume, you get a nasty surprise. The file position is evidently NOT changed by the call to "PBSetEOF". Thus, subsequent writing will begin at the old position, which may not be zero. Example: You have a file of 1 megabyte which you want to overwrite with new data and the position happens to be at the end of the file. You set the logical end-of-file to zero, the File Manager reports no error, and so you go ahead and write the new data (again with no error reported). You discover that the file now contains a megabyte of null characters followed by the new data! This is a quick way to fill a disk with garbage!

MORAL: Explicitly set the file position to zero whenever you set the logical end-of-file to zero. And in general, always set the position to less than or equal to the logical end-of-file whenever you reduce the latter.

- Anonymous(e)

Hiding from MacsBug

Under System 7, if you place MacsBug's resources in the system sub-folder called Preferences, Macsbug will ignore the resource file during startup. Place the MacsBug resources in the system folder only!

This is useful if you want to hide these resources from MacsBug.

- Greg Pribyl

Incline Village, Nevada

Making use of a fast Tool

The StreamEdit tool introduced with MPW 3.2 doesn’t actually add a great deal of functionality to MPW. However, its main advantage is that it’s fast. If you have any shell scripts that do repetitive string manipulations, you can usually speed them up by rewriting them to use StreamEdit.

For example, in one of my projects, I have a special shell script to construct the makefile. Among other things, this script scans a dependencies file, with lines that look like

Module1 Module2 Type

to indicate that “Module1” imports something from “Module2” (“Type” indicates whether the dependency is in the definition or implementation module).

The script used to scan this file by opening it in the editor and using Find commands, followed by Catenate commands to read from the current selection. It used to take about 15 minutes to execute. After I rewrote it to use StreamEdit, it took 90 seconds.

Even a simple thing like generating a rule to compile all the source files in the current directory can benefit from StreamEdit. Here’s the old way I used to build the object library:

Set Ident '[A-Za-z0-9]+'
Echo -n 'MyModLib.o ƒ'
For ThisModule in "{Mods}" .mod
 (Evaluate "{ThisModule}" =~ 
 / :({Ident})®1.mod/) 
 >Dev:Null
 Echo -n 
' 'ntt'"{Objs}"'{®1}'.mod.o'
End # For

And here’s the new way:

# 2
Set Ident '[A-Za-z0-9]+'
Echo -n 'MyModLib.o ƒ'
Files "{Mods}" .mod | 
 StreamEdit -d -e 
 "/:({Ident})®1.mod/ "
"print ' '; print -n"
" 'tt"{Objs}"'®1'.mod.o'"

Another advantage of StreamEdit is that, by avoiding use of editor commands like Open and Find, your script can execute in the background under ToolServer.

- Lawrence D’Oliveiro

Computer Services Dept.

University of Waikato

Hamilton, New Zealand

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

OmniOutliner Pro 4.2 - Pro version of th...
OmniOutliner Pro is a flexible program for creating, collecting, and organizing information. Give your creativity a kick start by using an application that's actually designed to help you think. It's... Read more
VLC Media Player 2.2.1 - Popular multime...
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
Nisus Writer Pro 2.1.1 - Multilingual wo...
Nisus Writer Pro is a powerful multilingual word processor, similar to its entry level products, but brings new features such as table of contents, indexing, bookmarks, widow and orphan control,... Read more
Tinderbox 6.2.0 - Store and organize you...
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals... Read more
OmniOutliner 4.2 - Organize your ideas,...
OmniOutliner is a flexible program for creating, collecting, and organizing information. Give your creativity a kick start by using an application that's actually designed to help you think. It's... Read more
Things 2.5.4 - Elegant personal task man...
Things is a task management solution that helps to organize your tasks in an elegant and intuitive way. Things combines powerful features with simplicity through the use of tags and its intelligent... Read more
NeoOffice 2014.10 - Mac-tailored, OpenOf...
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
iPhoto Library Manager 4.2 - Manage mult...
iPhoto Library Manager allows you to organize your photos among multiple iPhoto libraries, rather than having to store all of your photos in one giant library. You can browse the photos in all your... Read more
Web Snapper 3.3.8 - Capture entire Web p...
Web Snapper lets you capture Web pages exactly as they appear in your browser. You can send them to a file as images or vector-based, multi-page PDFs. It captures the whole Web page - eliminating the... Read more
TeamViewer 10.0.41404 - Establish remote...
TeamViewer gives you remote control of any computer or Mac over the Internet within seconds, or can be used for online meetings. Find out why more than 200 million users trust TeamViewer! Free for... Read more

Chainsaw Warrior: Lords of the Night has...
It's time to put the Darkness back in its place now that Chainsaw Warrior: Lords of the Night has officially made it to iOS. | Read more »
A World of Ice and Fire Lets You Stalk 2...
George R. R. Martin’s A World of Ice and Fire, by Random House, is a mobile guide to the epic series. The new update gives you the Journeys map feture that will let you track the movements of 25 different characters. But don't worry, you can protect... | Read more »
Gameloft Announces Battle Odyssey, a New...
Battle Odyssey, Gameloft's newest puzzle RPG, is coming to the App Store next week. Set in the world of Pondera, you will need to control the power of the elements to defend the world from evil. You'll be able to entlist over 500 allies to aid you... | Read more »
Fusion - HDR Camera (Photography)
Fusion - HDR Camera 1.0.0 Device: iOS Universal Category: Photography Price: $1.99, Version: 1.0.0 (iTunes) Description: Fusion creates HDR (high dynamic range) photos by capturing different exposures and then combining them into one... | Read more »
Sago Mini Toolbox (Education)
Sago Mini Toolbox 1.1 Device: iOS Universal Category: Education Price: $2.99, Version: 1.1 (iTunes) Description: Come build with the Sago Mini friends! Use a wrench, try a saw, or hammer some nails. From sewing hand puppets to... | Read more »
You Should Probably Grab Hitman GO While...
Hitman GO is a surprisingly cool (yet also incredibly drastic) departure from the Hitman series. It's well worth playing for any puzzle game fans out there, and at the moment you can get your hands - or garrotte if you will - on it for a mere $0.99... | Read more »
IFTTT is Bringing Do Button and Do Note...
IFTTT has announced Do Button and Do Note for the Apple Watch. Do Button lets you make your own personalized button that can connect to things like your Google Drive, control the temperature in your home with Nest Thermostat, or turn the lights on... | Read more »
How Many Days, Hours, and Minutes Are Le...
Countdown, by Yves Tscherry, is now available on the App Store. The app keeps track of countdowns to your favorite things such as someones birthday or days till the New Year. You can display the time in seconds, minutes, hours, days, weeks, months,... | Read more »
The All-New Misfit 2.0 App is Available...
Misfit has just given their app a complete overhaul. Misfit 2.0 now has a brand new interface with a sleek design and is easier to navigate. You'll be able to sync your Misfit device and look up health and fitness information faster than ever before... | Read more »
Halo: Spartan Strike (Games)
Halo: Spartan Strike 1.0 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0 (iTunes) Description: Delve into 30 challenging missions through cities and jungles using a devastating arsenal of weapons, abilities and... | Read more »

Price Scanner via MacPrices.net

TigerText Introduces First Secure Enterprise...
TigerText, a provider of secure, real-time messaging for the enterprise, has announced the launch of TigerText for the Apple Watch. TigerText for the Apple Watch enables users to securely send and... Read more
The Conservation Fund Partners with Apple To...
The Conservation Fund has announced that it will partner with Apple to help protect working forests in the United States. The Apple initiative will conserve more than 36,000 acres of working... Read more
Clearance 13-inch 2.6GHz Retina MacBook Pro a...
B&H Photo has clearance 2014 13″ 2.6GHz/128GB Retina MacBook Pros now available for $1099, or $200 off original MSRP. Shipping is free, and B&H charges NY sales tax only. Read more
Apple refurbished 2014 13-inch Retina MacBook...
The Apple Store has Apple Certified Refurbished 2014 13″ Retina MacBook Pros available for up to $400 off original MSRP, starting at $979. An Apple one-year warranty is included with each model, and... Read more
iMacs on sale for up to $205 off MSRP, NY tax...
B&H Photo has 21″ and 27″ iMacs on sale for up to $205 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1019 $80 off - 21″ 2.7GHz iMac: $1189 $110 off - 21″ 2.9GHz... Read more
Sale! 16GB iPhone 5S for $1 with service
Best Buy is offering 16GB iPhone 5Ss for $1.00 with 2-year activation at a participating cellular provider. Choose free home shipping and activation, or buy online and activate during in-store pickup... Read more
Apple refurbished 2014 MacBook Airs available...
The Apple Store has Apple Certified Refurbished 2014 MacBook Airs available starting at $679. An Apple one-year warranty is included with each MacBook, and shipping is free. These are currently the... Read more
27-inch 3.5GHz 5K iMac on sale for $2349, sav...
 Adorama has the 27″ 3.5GHz 5K iMac in stock today and on sale for $2349 including free shipping plus NY & NJ sales tax only. Their price is $150 off MSRP. For a limited time, Adorama will... Read more
Save up to $380 on an iMac with Apple refurbi...
The Apple Store has Apple Certified Refurbished iMacs available for up to $380 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 27″ 3.5GHz 5K iMac – $2119 $... Read more
iFixIt Teardown Awards 12-IInch Retina MacBoo...
iFixIt has posted its illustrated teardown of the new 12-inch MacBook Retina. They note that this new MacBook is less than half the thickness of the last Apple notebook called just “MacBook” back in... Read more

Jobs Board

*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
Communication Manager - *Apple* Pay - Apple...
**Job Summary** This position works within the Apple Pay Merchant Solutions team to create, as well as oversee the development of, materials for use by Apple Pay Read more
Project Manager / Business Analyst, WW *Appl...
…a senior project manager / business analyst to work within our Worldwide Apple Fulfillment Operations and the Business Process Re-engineering team. This role will work Read more
Marketing Program Manager, *Apple* Retail O...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
Engineering Manager for *Apple* Maps on the...
…the Maps App Team get to take part in just about any new feature in Apple Maps, often contributing a majority of the feature work. In our day-to-day engineering work, we Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.