Tips & Tidbits

By Scott T Boyd, Editor

Tip Of The Month

MPW Quoting Time Saver

Every self respecting Mac programmer knows that in MPW, string literals and shell variables containing spaces must be quoted. What many experienced shell users don’t know is that the option-space character, which looks just like a regular space, bypasses this requirement when dealing with the file system. Amaze your friends by typing Directory "{Boot}"Desktop Folder without any quotes (slip in that option-space while they’re not looking). It’s a great time saver and party ice breaker!

Without an option-space:

Directory "{Boot}"desktop folder

### Directory - Too many parameters were specified.

# Usage - Directory [-q | directory]

With an option-space, no error is returned:

Directory "{Boot}"Desktop Folder

- Paul Mercer

Slimming down “fat binaries” with MPW

Fat binaries contain both Macintosh 68K and PowerPC code, so they can run on any Mac hardware and take advantage of whatever processor is present.

A fat binary contains 68K executable 'CODE' resources and other standard Mac resources in the resource fork, and PowerPC Executable Format (PEF) code in the data fork. It also includes a 'cfrg' resource, to tell a Power Mac to ignore CODE resources at startup and look for PEF code in the data fork. A 68K Mac ignores the 'cfrg' resource and PEF code, using the 'CODE' resources instead.

This is fine for developers who only want to ship only one version of their product, and for users who want to be able to just click and go on any system, even when file-sharing across a network mixed with 68K and Power Macs. But lone power users with limited disk space may wish to perform liposuction on fat binaries, and MPW makes it easy.

To convert a fat binary to a “68K only”application:

/* 1 */
# MPW Script "To68K"
  If {#} != 1
    Echo "# Usage: {0} fat_application_name"
  Else
    Derez -skip cfrg "{1}" | Rez -o "{1}" # eliminate 'cfrg' resource
    Duplicate -y -r "{1}" "{1}.temp"      # eliminate data fork
    Rename -y "{1}.temp" "{1}"            # replace original file
  End

To convert a fat binary into a “Power Mac only” application:

/* 2 */
# MPW Script "ToPowerMac"
  If {#} != 1
    Echo "# Usage: {0} fat_application_name"
  Else
    Derez -skip CODE "{1}" | Rez -o "{1}" # eliminate 'CODE' resources
  End

Caveats: Neither of these scripts check if they are really operating on a fat binary, nor do they know whether a native version might need one or more CODEsegments, so be careful how you apply them, and please don’t perform surgery on your only copy of any file!

- Lee David Rimar, Absoft Corporation

Ever heard of setkey?

I’m just amazed at some of the SmartFriends™ I know who haven’t heard of SetKey, an MPW command that has been around for quite some time. It just goes to show how few people read release notes or manuals for MPW. Maybe it’s just that these people all worked at Apple, where coming by production versions of manuals can be enough of a chore that it’s not worth the trouble.

At any rate, SetKey lets you attach a script to any key or key combination on your keyboard, even the function keys on the extended keyboard. So tip #1 is to try out SetKey. SetKey uses the following syntax:

/* 3 */
SetKey <empty> | -r | [modifierkey-] key[-modifierkey-] key] [string]
    modifierkey = command | option | shift | control
    -r          # revert to the default key assignments

Tip #2 is to enter SetKey in a shell window, and see what’s already set. You might be surprised at some of the things MPWalready knows how to do with key combinations.

Function keys are F1-F15. Other keys are referenced by name, such as the following:

/* 4 */
setkey Option-Command-Downarrow         MoveEndOfFile
setkey Option-Command-Uparrow           MoveStartOfFile
setkey Option-Shift-Delete              Beep
setkey Option-Shift-Escape              Beep
setkey Option-Shift-Clear               'Clear § "{active}"'
setkey Option-Shift-Del                 Beep
setkey Option-Shift-Leftarrow           SelectWordLeft

For Tip #3 and following, here are some scripts Iuse a lot:

• To mark the current selection in the active window, Iuse function key F8.

/* 5 */
# mark current selection in the Active window
setkey F8   'Mark § "`Catenate "{Active}".§`" "{Active}" -y'

• Here’s a fun one. It sorts the current selection.

/* 6 */
# sort the current selection in the Active window
SetKey F12 'sort  -o "{SysTempFolder}MPW.Scratch" 
 "{Active}".§ ;  
     catenate "{SysTempFolder}MPW.Scratch" > "{Active}".§ ;  
     delete   "{SysTempFolder}MPW.Scratch"'

• Finally, here are three simple scripts Iuse frequently. I add them to a new menu, and Igive that menu the cloverleaf character from the command key as a title. The first line sets a variable to have the value of the cloverleaf character. Where you see the cloverleaf below, you’ll probably see a n character when you type control-Q.

/* 7 */
Set Key Cmd   # cloverleaf = ctl-Q

This one compiles the current selection, then dumps the object code that the C compiler generated.

/* 8 */
AddMenu {Key} 'C->DumpObj §'  'C "{Active}.§" -mc68020 -mbg 
 off -o "{SysTempFolder}temp.c.o"; 
 DumpObj "{SysTempFolder}temp.c.o" -co'

This one assembles the current selection, then dumps the resulting object code.

/* 9 */
AddMenu {Key} 'Asm->DumpObj §'  'Asm "{Active}.§" 
 -o "{SysTempFolder}temp.c.o"; 
     DumpObj "{SysTempFolder}temp.c.o" -co'

This one compares the current selection in the active window to the selection 
in the target window.

/* 10 */
AddMenu {Key} 'Compare {Active}.§ §'  
 'Compare "{Active}.§" "{Target}.§" >> "{Worksheet}"'

- Gordon Sheridan, General Magic

Assembling kährs

When putting together a Kährs wood plank floor, go ahead and shell out the thirty dollars or so for the “pull-up” tool. It’s not entirely obvious why you’d need it when you first start putting the floor together, although it looks like it might be handy to cinch up planks once you have the whole row down. It turns out not to help for that (the friction is simply too great along the length of the plank), but it does wonders when you start laying the last couple of rows. Up to that point, you can just use a tap-block and a mallet to tighten the new plank against the previous row. Once you get close to the far wall, though, there’s no room to swing the mallet, much less place the tap-block. The pull-up tool fits into the groove which is right against the wall, and gives you some room to swing the mallet, and pull the board into place.

- Al Borland, Chicago, IL