---
title: FSExtentType.readOnly
framework: fskit
role: symbol
role_heading: Case
path: fskit/fsextenttype/readonly
---

# FSExtentType.readOnly

An extent type to indicate read-only data.

## Declaration

```swift
case readOnly
```

## Discussion

Discussion Use this type to represent ranges in the file that data can be read but not written to.

## See Also

### Working with extent types

- [FSExtentType.data](fskit/fsextenttype/data.md)
- [FSExtentType.zeroFill](fskit/fsextenttype/zerofill.md)