6

Function Descriptions

This chapter describes the CIN functions you can use with LabVIEW. You can use these functions to perform simple and complex operations. These functions, organized into libraries called managers, range from low-level byte manipulation to routines for sorting data and managing memory. All CIN manager routines are platform-independent, so you can create CINs that work on all platforms supported by LabVIEW.

Refer to the Manager Overview section in Chapter 4, Programming Issues for CINs, for general information about the manager routines.

Memory Manager Functions

The memory manager functions can dynamically allocate, manipulate, and release memory.

To perform the following operations, use the functions listed:

•Handle and pointer verification:

–AZCheckHandle/DSCheckHandle

–AZCheckPtr/DSCheckPtr

•Handles, allocating and releasing:

–SetCINArraySize

–NumericArrayResize

–AZDispose Handle/DSDisposeHandle

–AZGetHandleSize/DSGetHandleSize

–AZNewHandle/DSNewHandle

–AZNewHClr/DSNewHClr

–AZRecoverHandle/DSRecoverHandle

–AZSetHandleSize/DSSetHandleSize

–AZSetHSzClr/DSSetHSzClr

•Handles, manipulating properties:

–AZHLock

–AZHPurge

Chapter 6 Function Descriptions

–AZHNoPurge

–AZHUnlock

•Memory utilities:

–AZHandAndHand/DSHandAndHand

–AZHandToHand/DSHandToHand

–AZPtrAndHand/DSPtrAndHand

–AZPtrToHand/DSPtrToHand

–AZPtrToXHand/DSPtrToXHand

–ClearMem

–MoveBlock

–SwapBlock

•Memory zone utilities:

–AZHeapCheck/DSHeapCheck

–AZMaxMem/DSMaxMem

–AZMemStats/DSMemStats

•Pointers, allocating and releasing:

–AZDisposePtr/DSDisposePtr

–AZNewPClr/DSNewPClr

–AZNewPtr/DSNewPtr

File Manager Functions

The file manager functions can create, open, and close files, write data to files, and read data from files. In addition, file manager routines can create directories, determine characteristics of files and directories, and copy files.

The file manager defines the Path data type for use in describing paths to files and directories. The data structure for the Path data type is private. Use file manager routines to create and manipulate the Path data type.

The file manager uses the int32 data type to describe permissions for files and directories. The manager uses only the least significant nine bits of the int32.

In UNIX, the nine bits of permissions correspond exactly to nine UNIX permission bits governing read, write, and execute permissions for user, group, and others. The following illustration shows permission bits in UNIX.

Chapter 6 Function Descriptions

In Windows, permissions are ignored for directories. For files, only bit 7 (the UNIX user write permission bit) is used. If this bit is clear, the file is read-only. Otherwise, you can write to the file.

In Macintosh, all nine bits are used for directories (folders). The bits which control read, write, and execute permissions, respectively, in UNIX are used to control See Files, Make Changes, and See Folders access rights, respectively, in Macintosh.

To perform the following operations, use the functions listed:

•Current position mark, positioning:

–FMSeek

–FMTell

•Default access rights information, getting:

–FGetDefGroup

•Directory contents, creating and determining:

–FListDir

–FNewDir

•End-of-file mark, positioning:

–FGetEOF

–FSetEOF

•File data to disk, flushing:

–FFlush

•File operations, performing basic:

–FCreate

–FCreateAlways

–FMClose

–FMOpen

Chapter 6 Function Descriptions

–FMRead

–FMWrite

•File range, locking:

– FLockOrUnlockRange

•File refnums, manipulating:

–FDisposeRefNum

–FlsARefNum

–FNewRefNum

–FRefNumToFD

–FRefNumToPath

•File, directory, and volume information determination:

–FExists

–FGetAccessRights

–FGetInfo

–FGetVolInfo

–FSetAccessRights

–FSetInfo

•Filenames and patterns, matching:

–FStrFitsPat

•Files and directories, moving and deleting:

–FMove

–FRemove

•Files, copying:

–FCopy

•Path type, determining:

–FGetPathType

–FlsAPathOfType

–FSetPathType

•Path, extracting information:

–FDepth

–FDirName

–FName

–FNamePtr

–FVolName