TweetFollow Us on Twitter

XCMD in Think C
Volume Number:5
Issue Number:5
Column Tag:HyperChat™

XCMD Corner: XCMDs in Think C

By Donald Koscheka, Arthur Young & Company, MacTutor Contributing Editor

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

Exploring XCMDs using just one development system is a lot like learning to play music on just one instrument. This is unfortunate because the Macintosh offers a virtual orchestra of development systems. As in learning to play a second instrument, learning a new development system often boils down to nothing more than learning how to transcribe the music.

Your programming environment is your instrument (writing a program is more like writing a piece of music than playing it). If you happen to own a copy of MPW you have no trouble using the code in this column because it’s all written for MPW. If you use a different development system , you’ll need to transcribe my listings to play on your particular development system.

In the past, I’ve been terribly guilty of catering to the MPW clique. My reasons were perhaps not so subtle: I use MPW at work; I’m comfortable with it, and I know that it directly supports an interface to XCMDs. After purchasing a copy of MPW 3.0, I realized that I might be making a mistake. For starters, MPW requires an expensive and time consuming learning curve; perhaps not everyone wants to spend several hundred dollars for sophistication they may never need.

Other development systems offer features that are not available in MPW such as a high quality source level debugger. Unfortunately several development systems lack key capabilities like support for XCMDs. Although you might expect LightspeedC to support XCMDs out of the box, it doesn’t. I’m not sure I understand the reason, but it doesn’t matter. Adding XCMD support to any compiler should be a very simple job.

Afterall, an XCMD is just another type of resource. If LightspeedC can create specialized resources such as window definitions and drivers, it already contains some of the support we need.

• Setting up the project

As luck, or design foresight, would have it, LightspeedC supports a generalized resource type called the “CODE” Resource. CODE resource projects are created like any other project in LightspeedC with the exception that you specify the project as a code resource in the set project type dialogue (see figure 1). You specify most of the information that the resource manger wants in this dialogue.

The custom header option requires a little elaboration. The standard interface to code resources branches to the entry point: main() . Selecting the Custom header option causes the entry point to be the first function in the file in which your main() is defined. XCMDs follow the second course as a matter of style.

Set the resource type to ‘XCMD’ or ‘XFCN’ according to the type of Hypercard interface you want.

Figure 1. Setting up a Code Resource using the Set Project Type Dialogue

• Writing the XCMD

In LightspeedC, a code resource has the same form as a “C” program. You define the entry point as:

 pascal void main( paramPtr ) 

ParamPtr is a pointer to a HyperTalk XCMDBlock. From there, your code looks like a vanilla “C” application. The same restrictions apply as on all CODE resources: no globals or statically initialized strings. CODE resources, of any kind, have no knowledge of globals at build time because they can’t make any assumptions about which application will load them! Strings suffer the same fate - “C” allocates statically defined strings in the application’s global pool. You’re not building an application so you don’t have a global pool - you must either define strings the hard way or load them in from the resource fork.

Listing 1 is a simple XCMD that returns the string “Hello World” to Hypercard. While the code itself is wholly unimaginative, it does demonstrate that the interface to Hypercard and the callback mechanism work satisfactorily. Anyhow there’s a time for imagination and a time to just get things done. Porting an interface falls to the latter category.

Include the header file, “HyperXCMD.h” (listing 2 ) in your code. This is the standard interface to Hypercard transposed for LightspeedC. There aren’t a lot of differences between the two as should be the case. Nonetheless this exercise proves quite useful in scoping out the idioms of a particular language implementation.

• The Hypercard “Glue”

You need to create a project which at the least includes MacTraps, your XCMD code and a special file called “XCMDGlue.c” (Listing 3) which interfaces (or glues) your XCMD to Hypertalk’s callback mechanism. I took the liberty of translating XCMDGlue.in.c from MPW “C” to LightspeedC. The major difference between the MPW and Think versions of the glue is that I use the CallPascal function available in LightspeedC to jump to the subroutine pointed to by paramPtr->entryPoint. Pascal routines push parameters from left to right and the subroutine is responsible for clearing the stack parameters. “C” pushes from right to left and the caller clears the stack.

We know that the callback engine uses the Pascal calling sequence because the parameters aren’t left on the stack after the call. Whether we push from right to left or left to right isn’t relevant here for an obvious reason that’s left as an exercise to the reader.

Add XCMDGlue.c to the project rather than including it at the end of the XCMDS source code as is the case with MPW. I like this feature of Think “C” - you keep track of the source modules at the project level and not at the source code level.

• Creating the resource

Once all modules compile,use the “Create Code Resource” menu option to create the code resource. LightspeedC presents a dialogue asking for the name of an output file. Enter the name of a file but not your output stack: LightspeedC completely erases the previous contents of both forks of the output file before writing out the code resource!

Select the “smart link” option when creating a code resource. Your links will be slower, but your XCMDs will be quite a bit smaller (The example in listing 3 compiles to 12.5K with smart link of and 2.5K with smart link on). Of course, you can speed up turnaround during development by leaving this option unselected.

That’s it! Use ResEdit or Rescopy to copy the XCMD into your stack. Perhaps LightspeedC will release a future version of “C” that will build code resources directly into the target file (if you try this now, the entire contents of the target file will be lost). In the meantime, the extra step needed to copy the resource into your stack is a small price to pay for an outstanding development system.

I hope the information in this article will help those of you who need to create an XCMD interface for another development system. The process is really rather simple and it provides you one of those rare opportunities in programming where you can get a lot done without doing a lot of work!

Listing 1:

/********************************/
/* File: SimpleXCMD.c*/
/* */
/* This is what a simple XCMD */
/* written in Lightspeed “C”*/
/* In order to build this code*/
/* resource, you will need the*/
/* two files “HyperXCMD.h” and*/
/* XCMDGlue.c.   */
/* */
/* ----------------------------  */
/* To Build:*/
/* */
/* (1) Create a project using */
/* this file as well as the */
/* XCMD.Glue.c file. (Set */
/* project type to XCMD (or */
/* XFCN) from the Project menu.  */
/* */
/* (2) Bring the project up to*/
/* date.*/
/* */
/* (3) Build Code Resource. */
/* */
/* (4) Use ResEdit to copy the   */
/* resource to your stack.*/
/********************************/

#include<MacTypes.h>
#include<OSUtil.h>
#include<MemoryMgr.h>
#include<FileMgr.h>
#include<ResourceMgr.h>
#include  “HyperXCmd.h”

pascal void main( paramPtr )
 XCmdBlockPtr  paramPtr;
{
 char theString[256];/* A “Pascal” String */

 theString[0] = ‘\0x0B’;  /* Remember, static*/
 theString[1] = ‘H’; /* strings are placed*/
 theString[2] = ‘E’; /* in the global pool*/
 theString[3] = ‘L’; /* CODE resources such */
 theString[4] = ‘L’; /* as XCMDS and XFCNS*/
 theString[5] = ‘O’; /* don’t have access to */
 theString[6] = ‘ ‘; /* globals so you have*/
 theString[7] = ‘W’; /* to discretely set the*/
 theString[8] = ‘O’; /* string’s value */
 theString[9] = ‘R’;
 theString[10]= ‘L’;
 theString[11]= ‘D’;

 /* A sample callback example */
 paramPtr->returnValue = PasToZero( paramPtr, &theString );
}
Listing 2:

/************************************/
/* File:HyperXCmd.h  */
/* */
/* Interface for standard */ 
/* HyperCard callback routines.    */
/* */
/* Based on original work by*/
/* Dan Winkler of Apple Computer */
/* */
/************************************/

typedef struct Str31 {
 char data[32];
 } Str31;
typedef  Str31 * Str31Ptr;

typedef struct XCmdBlock {
 short  paramCount;       
    Handle  params[16];
    Handle  returnValue;      
    Boolean passFlag; 
    
    void  (*entryPoint)();    
    short request;  
    short result;  
    longinArgs[8];
    longoutArgs[4];
} XCmdBlock;
typedef XCmdBlock*XCmdBlockPtr; 

  /* Callback codes  */
#define xresSucc 0
#define xresFail 1 
#define xresNotImp 2 
  
  /* Callback request codes */
#define xreqSendCardMessage 1 
#define xreqEvalExpr 2 
#define xreqStringLength  3 
#define xreqStringMatch   4 

#define xreqZeroBytes         6 
#define xreqPasToZero7 
#define xreqZeroToPas8 
#define xreqStrToLong9 
#define xreqStrToNum 10 
#define xreqStrToBool11 
#define xreqStrToExt 12 
#define xreqLongToStr13 
#define xreqNumToStr 14 
#define xreqNumToHex 15 
#define xreqBoolToStr16 
#define xreqExtToStr 17 
#define xreqGetGlobal18 
#define xreqSetGlobal19 
#define xreqGetFieldByName20 
#define xreqGetFieldByNum 21 
#define xreqGetFieldByID  22 
#define xreqSetFieldByName23 
#define xreqSetFieldByNum 24 
#define xreqSetFieldByID  25 
#define xreqStringEqual       26 
#define xreqReturnToPas       27 
#define xreqScanToReturn      28 
#define xreqScanToZero        39  

/* 
 “Prototypes” for the Callbacks.  Project 
 must include XCmdGlue.c.  
*/

 
pascal void SendCardMessage();     
pascal Handle  EvalExpr();
pascal long StringLength(); 
pascal Ptr  StringMatch();
pascal void ZeroBytes();
pascal Handle  PasToZero();
pascal void ZeroToPas();
pascal long StrToLong();
pascal long StrToNum();
pascal Boolean   StrToBool();
pascal void StrToExt();
pascal void LongToStr();
pascal void NumToStr();
pascal void NumToHex();
pascal void BoolToStr();
pascal void ExtToStr();
pascal Handle  GetGlobal();
pascal void SetGlobal();
pascal Handle  GetFieldByName();
pascal Handle  GetFieldByNum();
pascal Handle  GetFieldByID();
pascal void SetFieldByName();
pascal void SetFieldByNum();
pascal void SetFieldByID();
pascal Boolean   StringEqual();
pascal void ReturnToPas();
pascal void ScanToReturn();
pascal void ScanToZero();
Listing 3:

/************************************/
/* File: XCMDGlue.c*/
/* */
/* Callback routines for XCMDs*/
/* and XFCNs.  This file should  */
/* be included in your project*/
/* */
/* Based on original work by*/
/* Dan Winkler of Apple Computer */
/* */
/************************************/

#include<MacTypes.h>
#include<OSUtil.h>
#include<MemoryMgr.h>
#include<FileMgr.h>
#include<ResourceMgr.h>
#include  “HyperXCmd.h”
#include<math.h>

pascal void SendCardMessage(paramPtr,msg)
 XCmdBlockPtr  paramPtr;  
 StringPtrmsg;
/***********************
* Send a message back to 
* hypercard.  The input message
* is a Pascal String
***********************/
{
 paramPtr->inArgs[0] = (long)msg;
 paramPtr->request = xreqSendCardMessage;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle EvalExpr(paramPtr,expr)
 XCmdBlockPtr  paramPtr;  
 StringPtrexpr;
/***********************
* Evaluate a Hypertalk expression
* returning the result as a “C” 
* string
***********************/
{
 paramPtr->inArgs[0] = (long)expr;
 paramPtr->request = xreqEvalExpr;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal long StringLength(paramPtr,strPtr)
 XCmdBlockPtr  paramPtr;
 StringPtrstrPtr;
/***********************
* Counts the number of 
* characters in the input 
* string from StrPtr to end
* of string (zero byte)
***********************/
{
 paramPtr->inArgs[0] = (long)strPtr;
 paramPtr->request = xreqStringLength;
    CallPascal( paramPtr->entryPoint );
 return (long)paramPtr->outArgs[0];
}

pascal Ptr StringMatch(paramPtr,pattern,target)
 XCmdBlockPtr  paramPtr;  
 StringPtrpattern;
 Ptr    target;
/***********************
* Case-insensitive match 
* for pattern anywhere in
* target, 
* 
* Returns a pointer to first
* character of the first match,
* in target or NIL if no match
* found.  pattern is a Pascal string,
* and target is a zero-terminated string.
***********************/
{
 paramPtr->inArgs[0] = (long)pattern;
 paramPtr->inArgs[1] = (long)target;
 paramPtr->request = xreqStringMatch;
    CallPascal( paramPtr->entryPoint );
 return (Ptr)paramPtr->outArgs[0];
}

pascal void ZeroBytes(paramPtr,dstPtr,longCount)
 XCmdBlockPtr  paramPtr;  
 Ptr    dstPtr;  
 long   longCount;
/***********************
* Clear memory starting at destPtr
* through destPtr+longCount
***********************/
{
 paramPtr->inArgs[0] = (long)dstPtr;
 paramPtr->inArgs[1] = longCount;
 paramPtr->request = xreqZeroBytes;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle PasToZero(paramPtr,pasStr)
 XCmdBlockPtr  paramPtr;
 StringPtrpasStr;
/***********************
* Convert a Pascal string (STR255)
* to a zero-terminated string.  
* Returns a handle to a zero-terminated
* string.  The caller must dispose the handle.
*
* Useful for setting the result or
* an argument you send from 
* an XCMD to HyperTalk.
***********************/
{
 paramPtr->inArgs[0] = (long)pasStr;
 paramPtr->request = xreqPasToZero;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal void ZeroToPas(paramPtr,zeroStr,pasStr)
 XCmdBlockPtr  paramPtr;  
 char   *zeroStr;
 StringPtrpasStr;
/***********************
* Copy the zero-terminated
* string into the Pascal String.
*
* You create the Pascal string 
* and pass it by reference.
*
***********************/
{
 paramPtr->inArgs[0] = (long)zeroStr;
 paramPtr->inArgs[1] = (long)pasStr;
 paramPtr->request = xreqZeroToPas;
    CallPascal( paramPtr->entryPoint );
}

pascal long StrToLong(paramPtr,strPtr)
 XCmdBlockPtr  paramPtr;  
 Str31  *strPtr;
/***********************
* Convert a string of ASCII
* characters to an unsigned 
* long integer.
***********************/
{
 paramPtr->inArgs[0] = (long)strPtr;
 paramPtr->request = xreqStrToLong;
    CallPascal( paramPtr->entryPoint );
 return (long)paramPtr->outArgs[0];
}

pascal long StrToNum(paramPtr,str)
 XCmdBlockPtr  paramPtr;  
 Str31  *str;
/***********************
* Convert a string of ASCII
* characters to a signed 
* long integer.
***********************/
{
 paramPtr->inArgs[0] = (long)str;
 paramPtr->request = xreqStrToNum;
    CallPascal( paramPtr->entryPoint );
 return paramPtr->outArgs[0];
}

pascal Boolean StrToBool(paramPtr,str)
 XCmdBlockPtr  paramPtr;
 Str31  *str;
/***********************
* Convert the Pascal strings
* ‘true’ and ‘false’ to booleans.
***********************/
{
 paramPtr->inArgs[0] = (long)str;
 paramPtr->request = xreqStrToBool;
    CallPascal( paramPtr->entryPoint );
 return (Boolean)paramPtr->outArgs[0];
}

pascal void StrToExt(paramPtr,str,myext)
 XCmdBlockPtr  paramPtr;
 Str31  *str;  
 long   *myext;
/***********************
* Convert a string of ASCII digits 
* to an extended long integer.
*
* The return value is passed
* by reference and you must
* asllocate the space before 
* calling this routine.
***********************/
{
 paramPtr->inArgs[0] = (long)str;
 paramPtr->inArgs[1] = (long)myext;
 paramPtr->request = xreqStrToExt;
    CallPascal( paramPtr->entryPoint );
}

pascal void LongToStr(paramPtr,posNum,mystr)
 XCmdBlockPtr  paramPtr;  
 long   posNum;  
 Str31  *mystr;
/***********************
* Convert an unsigned long integer
* to a pascal string representation
* Useful for sending numbers back 
* to Hypercard.
*
*  You create mystr and pass
* it by reference.
***********************/
{
 paramPtr->inArgs[0] = (long)posNum;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqLongToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal void NumToStr(paramPtr,num,mystr)
 XCmdBlockPtr  paramPtr;  
 long   num;
 Str31  *mystr;
/***********************
* Convert a signed long integer
* to a pascal string representation
* Useful for sending numbers back 
* to Hypercard.
*
*  You create mystr and pass
* it by reference.
***********************/
{
 paramPtr->inArgs[0] = num;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqNumToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal void NumToHex(paramPtr,num,nDigits,mystr)
 XCmdBlockPtr  paramPtr;  
 long   num;
 short  nDigits; 
 Str31  *mystr;
/***********************
* Convert an unsigned long integer
* to a hexadecimal number and put it
* into a Pascal string.
*
* The “output” string is passed
* by reference.
***********************/
{
 paramPtr->inArgs[0] = num;
 paramPtr->inArgs[1] = nDigits;
 paramPtr->inArgs[2] = (long)mystr;
 paramPtr->request = xreqNumToHex;
    CallPascal( paramPtr->entryPoint );
}

pascal void BoolToStr(paramPtr,bool,mystr)
 XCmdBlockPtr  paramPtr;  
 Booleanbool;  
 Str31  *mystr;
/***********************
* Convert a boolean to 
* ‘true’ or ‘false’.  
*
* The “output” string is passed
* by reference.
***********************/
{
 paramPtr->inArgs[0] = (long)bool;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqBoolToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal void ExtToStr( paramPtr, myext, mystr)
 XCmdBlockPtr  paramPtr;  
 char   *myext;  
 Str31  *mystr;
/***********************
* Convert an extended long
* to its string representation
*
* The “output” string is passed
* by reference.
***********************/
{
 paramPtr->inArgs[0] = (long)myext;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqExtToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle GetGlobal(paramPtr,globName)
 XCmdBlockPtr  paramPtr;  
 StringPtrglobName;
/***********************
* Return a handle to a zero-terminated
* string containing the value of 
* the specified HyperTalk global variable.
***********************/
{
 paramPtr->inArgs[0] = (long)globName;
 paramPtr->request = xreqGetGlobal;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal void SetGlobal(paramPtr,globName,globValue)
 XCmdBlockPtr  paramPtr;  
 StringPtrglobName;
 Handle globValue;
/***********************
* Set the value of the specified 
* HyperTalk global variable to be
* the zero-terminated string in globValue.
* The contents of globValue
* are copied, you dispose the
* handle
***********************/
{
 paramPtr->inArgs[0] = (long)globName;
 paramPtr->inArgs[1] = (long)globValue;
 paramPtr->request = xreqSetGlobal;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle GetFieldByName(paramPtr,cardFieldFlag,fieldName)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 StringPtrfieldName;
/***********************
* Return a handle to a zero-terminated
* string containing the value of 
* field fieldName on the current 
* card.  You must dispose the handle.
*
* Set cardfieldFlag to ture if
* you want the contents of a card
* field or to false if you want
* the contents of a bkgnd field
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = (long)fieldName;
 paramPtr->request = xreqGetFieldByName;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal Handle GetFieldByNum(paramPtr,cardFieldFlag,fieldNum)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldNum;
/***********************
* Returns a copy of the contents of the field whose number is
* fieldnum on the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldNum;
 paramPtr->request = xreqGetFieldByNum;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal Handle GetFieldByID(paramPtr,cardFieldFlag,fieldID)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldID;
/***********************
* Returns a copy of the contents of the field whose id is
* fieldID on the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldID;
 paramPtr->request = xreqGetFieldByID;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal void SetFieldByName(paramPtr,cardFieldFlag,fieldName,fieldVal)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 StringPtrfieldName; 
 Handle fieldVal;
/***********************
* Set the value of the field whose name is fieldName on 
* the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = (long)fieldName;
 paramPtr->inArgs[2] = (long)fieldVal;
 paramPtr->request = xreqSetFieldByName;
    CallPascal( paramPtr->entryPoint );
}

pascal void SetFieldByNum(paramPtr,cardFieldFlag,fieldNum,fieldVal)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldNum;
 Handle fieldVal;
/***********************
* Set the value of the field whose number is fieldnum on 
* the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldNum;
 paramPtr->inArgs[2] = (long)fieldVal;
 paramPtr->request = xreqSetFieldByNum;
    CallPascal( paramPtr->entryPoint );
}

pascal void SetFieldByID(paramPtr,cardFieldFlag,fieldID,fieldVal)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldID; 
 Handle fieldVal;
/***********************
* Set the value of the field whose id is fieldID on 
* the current card.
* You dispose the handle when
* you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldID;
 paramPtr->inArgs[2] = (long)fieldVal;
 paramPtr->request = xreqSetFieldByID;
    CallPascal( paramPtr->entryPoint );
}

pascal Boolean StringEqual(paramPtr,str1,str2)
 XCmdBlockPtr  paramPtr;  
 Str31  *str1; 
 Str31  *str2;
/***********************
* Returns true if the strings match, false otherwise.
* Compare is case insensitive
***********************/
{
 paramPtr->inArgs[0] = (long)str1;
 paramPtr->inArgs[1] = (long)str2;
 paramPtr->request = xreqStringEqual;
    CallPascal( paramPtr->entryPoint );
 return (Boolean)paramPtr->outArgs[0];
}

pascal void ReturnToPas(paramPtr,zeroStr,pasStr)
 XCmdBlockPtr  paramPtr;  
 Ptr    zeroStr; 
 StringPtrpasStr;
/***********************
* Collect characters from zeroStr
* to the next carriage Return and return 
* them in the Pascal string pasStr. 
* If no Return found, collect chars
* until the end of the string (zero)
***********************/
{
 paramPtr->inArgs[0] = (long)zeroStr;
 paramPtr->inArgs[1] = (long)pasStr;
 paramPtr->request = xreqReturnToPas;
    CallPascal( paramPtr->entryPoint );
}

pascal void ScanToReturn(paramPtr,scanHndl)
 XCmdBlockPtr  paramPtr;  
 Ptr    *scanHndl;
/***********************
* Position the pointer, scanPtr,at a Return character
* or a zero byte. 
***********************/
{
 paramPtr->inArgs[0] = (long)scanHndl;
 paramPtr->request = xreqScanToReturn;
    CallPascal( paramPtr->entryPoint );
}

pascal void ScanToZero(paramPtr,scanHndl)
 XCmdBlockPtr  paramPtr;  
 Ptr    *scanHndl;
/***********************
* Position the pointer, scanPtr,
* at a  zero byte. 
***********************/
{
 paramPtr->inArgs[0] = (long)scanHndl;
 paramPtr->request = xreqScanToZero;
    CallPascal( paramPtr->entryPoint );
}

 
AAPL
$97.67
Apple Inc.
+1.41
MSFT
$43.63
Microsoft Corpora
+0.89
GOOG
$511.17
Google Inc.
-13.34

MacTech Search:
Community Search:

Software Updates via MacUpdate

Coda 2.5 - One-window Web development su...
Coda is a powerful Web editor that puts everything in one place. An editor. Terminal. CSS. Files. With Coda 2, we went beyond expectations. With loads of new, much-requested features, a few... Read more
Arq 4.6.1 - Online backup to Google Driv...
Arq is super-easy online backup for the Mac. Back up to your own Google Drive storage (15GB free storage), your own Amazon Glacier ($.01/GB per month storage) or S3, or any SFTP server. Arq backs up... Read more
Airfoil 4.8.10 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
Apple iMovie 10.0.6 - Edit personal vide...
With an all-new design, Apple iMovie lets you enjoy your videos like never before. Browse your clips more easily, instantly share your favorite moments, and create beautiful HD movies and Hollywood-... Read more
OnyX 2.8.8 - Maintenance and optimizatio...
OnyX is a multifunctional utility for OS X. It allows you to verify the startup disk and the structure of its System files, to run miscellaneous tasks of system maintenance, to configure the hidden... Read more
Parallels Desktop 10.1 - Run Windows app...
Parallels Desktop is simply the world's bestselling, top-rated, and most trusted solution for running Windows applications on your Mac. With Parallels Desktop for Mac, you can seamlessly run both... Read more
Apple Keynote 6.5 - Apple's present...
Apple Keynote makes it simple to create and deliver beautiful presentations. Powerful tools and dazzling effects bring your ideas to life. You can work seamlessly between Mac and iOS devices. And... Read more
OmniPlan 2.3.7 - Robust project manageme...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more
Flavours 1.1.16 - Create and apply theme...
Flavours is a Mac application that allow users to create, apply and share beautifully designed themes. Classy Give your Mac a gorgeous new look by applying delicious themes! Easy Unleash your... Read more
Duplicate Annihilator 5.1.0 - Find and d...
Duplicate Annihilator takes on the time-consuming task of comparing the images in your iPhoto library using effective algorithms to make sure that no duplicate escapes. Duplicate Annihilator detects... Read more

Latest Forum Discussions

See All

My Very Hungry Caterpillar (Education)
My Very Hungry Caterpillar 1.0.0 Device: iOS Universal Category: Education Price: $3.99, Version: 1.0.0 (iTunes) Description: Care for your very own Very Hungry Caterpillar! My Very Hungry Caterpillar will captivate you as he crawls... | Read more »
Dungeon Dick (Games)
Dungeon Dick 1.1 Device: iOS Universal Category: Games Price: $.99, Version: 1.1 (iTunes) Description: Dungeon Dick is a fantasy adventure where you must discover the wicked plot to destroy the lands . 'Fling' at your foes and land... | Read more »
Here’s How the Apple Watch Could Transfo...
With the Apple Watch’s generic release date of, “early 2015” hovering on the horizon, it’s only a matter of time before gamers begin to ask “What’s in it for us?” The obvious choice would be to place entire games directly on the face of the watch,... | Read more »
Republique Episode 3: Ones & Zeroes...
Republique Episode 3: Ones & Zeroes is Available Now Posted by Rob Rich on October 17th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Loot Raiders Review
Loot Raiders Review By Campbell Bird on October 17th, 2014 Our Rating: :: PRESS BUTTON, GET LOOTUniversal App - Designed for iPhone and iPad This menu-based loot game is suitable to compel those with pretty extreme loot lust.   | Read more »
Angry Birds are Crashing Puzzle & Dr...
Angry Birds are Crashing Puzzle & Dragons Next Week Posted by Rob Rich on October 17th, 2014 [ permalink ] Next week, Puzzle & Dragons is getting a little angry. Because, you know, Angry Birds. It’s a… a pun. I thought… never mind. | Read more »
Incandescence Review
Incandescence Review By Andrew Fisher on October 17th, 2014 Our Rating: :: ALL TAPPED OUTUniversal App - Designed for iPhone and iPad Incandescence promises intense tapping action, but isn’t particularly fun.   | Read more »
Lion Pig (Games)
Lion Pig 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: "Leaving aside the biology of how a pig and a lion might meet, fall in love, and create this curious cross-breed, Lion Pig is a... | Read more »
Zero Lives (Games)
Zero Lives 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Zero Lives is a puzzle game. Simple and elegant at its core but deep and captivating the more you play. Each puzzle will challenge... | Read more »
#SUPERHYPER (Games)
#SUPERHYPER 001 Device: iOS Universal Category: Games Price: $.99, Version: 001 (iTunes) Description: "This is a game that fans of challenging minimalist arcade games, not to mention pixel art, should keep an eye on" - Touch Arcade "... | Read more »

Price Scanner via MacPrices.net

Apple Pay Available to Millions of Visa Cardh...
Visa Inc. brings secure, convenient payments to iPad Air 2 and iPad mini 3as well as iPhone 6 and 6 Plus. Starting October 20th, eligible Visa cardholders in the U.S. will be able to use Apple Pay,... Read more
Textkraft Pocket – the missing TextEdit for i...
infovole GmbH has announced the release and immediate availability of Textkraft Pocket 1.0, a professional text editor and note taking app for Apple’s iPhone. In March 2014 rumors were all about... Read more
C Spire to offer iPad Air 2 and iPad mini 3,...
C Spire on Friday announced that it will offer iPad Air 2 and iPad mini 3, both with Wi-Fi + Cellular, on its 4G+ LTE network in the coming weeks. C Spire will offer the new iPads with a range of... Read more
Belkin Announces Full Line of Keyboards and C...
Belkin International has unveiled a new lineup of keyboard cases and accessories for Apple’s newest iPads, featuring three QODE keyboards and a collection of thin, lightweight folios for both the... Read more
Verizon offers new iPad Air 2 preorders for $...
Verizon Wireless is accepting preorders for the new iPad Air 2, cellular models, for $100 off MSRP with a 2-year service agreement: - 16GB iPad Air 2 WiFi + Cellular: $529.99 - 64GB iPad Air 2 WiFi... Read more
Price drops on refurbished Mac minis, now ava...
The Apple Store has dropped prices on Apple Certified Refurbished previous-generation Mac minis, with models now available starting at $419. Apple’s one-year warranty is included with each mini, and... Read more
Apple refurbished 2014 MacBook Airs available...
The Apple Store has Apple Certified Refurbished 2014 MacBook Airs available for up to $180 off the cost of new models. An Apple one-year warranty is included with each MacBook, and shipping is free.... Read more
Refurbished 2013 MacBook Pros available for u...
The Apple Store has Apple Certified Refurbished 13″ and 15″ MacBook Pros available starting at $929. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros (4GB RAM/... Read more
WaterField Designs Unveils Outback iPad Slip...
Fresh on the heels of Apple’s announcement Thursday, WaterField Designs unveils its new Outback Slip Case for the iPad Air 2 and iPad mini 3 — a custom-fitted case for the just-announced Apple iPads... Read more
Apple Introduces iPad Air 2 & iPad mini 3...
Apple on Thursday introduced iPad Air 2, slimmed down again to just 6.1 mm, and weighing less than a pound. iPad Air 2 also features an improved Retina display claimed to deliver enhanced contrast... Read more

Jobs Board

Position Opening at *Apple* - Apple (United...
**Job Summary** At the Apple Store, you connect business professionals and entrepreneurs with the tools they need in order to put Apple solutions to work in their Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** The Apple Store is a retail environment like no other - uniquely focused on delivering amazing customer experiences. As an Expert, you introduce people Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** As businesses discover the power of Apple computers and mobile devices, it's your job - as a Solutions Engineer - to show them how to introduce these Read more
Position Opening at *Apple* - Apple (United...
…Summary** As a Specialist, you help create the energy and excitement around Apple products, providing the right solutions and getting products into customers' hands. You 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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.