---
title: HFSMasterDirectoryBlock
framework: Kernel
role: symbol
role_heading: Structure
platforms: [macOS 10.6+]
path: kernel/hfsmasterdirectoryblock
---

# HFSMasterDirectoryBlock

## Declaration

```occ
typedef struct HFSMasterDirectoryBlock {
    ...
} HFSMasterDirectoryBlock;
```

## Topics

### Instance Properties

- [drAlBlSt](kernel/hfsmasterdirectoryblock/1577882-dralblst.md)
- [drAlBlkSiz](kernel/hfsmasterdirectoryblock/1578082-dralblksiz.md)
- [drAllocPtr](kernel/hfsmasterdirectoryblock/1578045-drallocptr.md)
- [drAtrb](kernel/hfsmasterdirectoryblock/1578058-dratrb.md)
- [drCTClpSiz](kernel/hfsmasterdirectoryblock/1577994-drctclpsiz.md)
- [drCTExtRec](kernel/hfsmasterdirectoryblock/1578121-drctextrec.md)
- [drCTFlSize](kernel/hfsmasterdirectoryblock/1578209-drctflsize.md)
- [drClpSiz](kernel/hfsmasterdirectoryblock/1578060-drclpsiz.md)
- [drCrDate](kernel/hfsmasterdirectoryblock/1577878-drcrdate.md)
- [drDirCnt](kernel/hfsmasterdirectoryblock/1578159-drdircnt.md)
- [drEmbedExtent](kernel/hfsmasterdirectoryblock/1577977-drembedextent.md)
- [drEmbedSigWord](kernel/hfsmasterdirectoryblock/1578229-drembedsigword.md)
- [drFilCnt](kernel/hfsmasterdirectoryblock/1577982-drfilcnt.md)
- [drFndrInfo](kernel/hfsmasterdirectoryblock/1578008-drfndrinfo.md)
- [drFreeBks](kernel/hfsmasterdirectoryblock/1578047-drfreebks.md)
- [drLsMod](kernel/hfsmasterdirectoryblock/1577922-drlsmod.md)
- [drNmAlBlks](kernel/hfsmasterdirectoryblock/1578106-drnmalblks.md)
- [drNmFls](kernel/hfsmasterdirectoryblock/1578103-drnmfls.md)
- [drNmRtDirs](kernel/hfsmasterdirectoryblock/1578088-drnmrtdirs.md)
- [drNxtCNID](kernel/hfsmasterdirectoryblock/1578206-drnxtcnid.md)
- [drSigWord](kernel/hfsmasterdirectoryblock/1578152-drsigword.md)
- [drVBMSt](kernel/hfsmasterdirectoryblock/1578023-drvbmst.md)
- [drVN](kernel/hfsmasterdirectoryblock/1578003-drvn.md)
- [drVSeqNum](kernel/hfsmasterdirectoryblock/1578150-drvseqnum.md)
- [drVolBkUp](kernel/hfsmasterdirectoryblock/1577907-drvolbkup.md)
- [drWrCnt](kernel/hfsmasterdirectoryblock/1578054-drwrcnt.md)
- [drXTClpSiz](kernel/hfsmasterdirectoryblock/1578077-drxtclpsiz.md)
- [drXTExtRec](kernel/hfsmasterdirectoryblock/1577963-drxtextrec.md)
- [drXTFlSize](kernel/hfsmasterdirectoryblock/1578070-drxtflsize.md)

## See Also

### Format

- [HFSCatalogFile](kernel/hfscatalogfile.md)
- [HFSCatalogFolder](kernel/hfscatalogfolder.md)
- [HFSCatalogKey](kernel/hfscatalogkey.md)
- [HFSCatalogThread](kernel/hfscatalogthread.md)
- [HFSExtentDescriptor](kernel/hfsextentdescriptor.md)
- [HFSExtentKey](kernel/hfsextentkey.md)
- [HFSPlusAttrData](kernel/hfsplusattrdata.md)
- [HFSPlusAttrExtents](kernel/hfsplusattrextents.md)
- [HFSPlusAttrForkData](kernel/hfsplusattrforkdata.md)
- [HFSPlusAttrInlineData](kernel/hfsplusattrinlinedata.md)
- [HFSPlusAttrKey](kernel/hfsplusattrkey.md)
- [HFSPlusBSDInfo](kernel/hfsplusbsdinfo.md)
- [HFSPlusCatalogFile](kernel/hfspluscatalogfile.md)
- [HFSPlusCatalogFolder](kernel/hfspluscatalogfolder.md)
- [HFSPlusCatalogKey](kernel/hfspluscatalogkey.md)
- [HFSPlusCatalogThread](kernel/hfspluscatalogthread.md)
- [HFSPlusExtentDescriptor](kernel/hfsplusextentdescriptor.md)
- [HFSPlusExtentKey](kernel/hfsplusextentkey.md)
- [HFSPlusForkData](kernel/hfsplusforkdata.md)
- [HFSPlusVolumeHeader](kernel/hfsplusvolumeheader.md)
- [HFSUniStr255](kernel/hfsunistr255.md)