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

# HFSExtentDescriptor

## Declaration

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

## Topics

### Instance Properties

- [blockCount](kernel/hfsextentdescriptor/1577858-blockcount.md)
- [startBlock](kernel/hfsextentdescriptor/1578086-startblock.md)

## See Also

### Format

- [HFSCatalogFile](kernel/hfscatalogfile.md)
- [HFSCatalogFolder](kernel/hfscatalogfolder.md)
- [HFSCatalogKey](kernel/hfscatalogkey.md)
- [HFSCatalogThread](kernel/hfscatalogthread.md)
- [HFSExtentKey](kernel/hfsextentkey.md)
- [HFSMasterDirectoryBlock](kernel/hfsmasterdirectoryblock.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)