---
title: firmlink
framework: system
role: symbol
role_heading: Type Property
path: system/fileflags/firmlink
---

# firmlink

File is a firmlink.

## Declaration

```swift
static var firmlink: FileFlags { get }
```

## Discussion

Discussion Firmlinks are used by macOS to create transparent links between the read-only system volume and writable data volume. For example, the /Applications folder on the system volume is a firmlink to the /Applications folder on the data volume, allowing the user to see both system- and user-installed applications in a single folder. The corresponding C constant is SF_FIRMLINK. note: This flag may only be changed by the superuser.