---
title: fileIdentifier
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/urlresourcevalues/fileidentifier
---

# fileIdentifier

The file system’s internal inode identifier for the item.

## Declaration

```swift
var fileIdentifier: UInt64? { get }
```

## Discussion

Discussion This value isn’t stable for all file systems or across all mounts. Use this value sparingly and don’t persist it. You can use it, for example, to match URLs from the URL enumerator with paths from FSEvents.

## See Also

### File values

- [documentIdentifier](foundation/urlresourcevalues/documentidentifier.md)
- [fileContentIdentifier](foundation/urlresourcevalues/filecontentidentifier.md)
- [fileAllocatedSize](foundation/urlresourcevalues/fileallocatedsize.md)
- [fileProtection](foundation/urlresourcevalues/fileprotection.md)
- [fileResourceIdentifier](foundation/urlresourcevalues/fileresourceidentifier.md)
- [fileResourceType](foundation/urlresourcevalues/fileresourcetype.md)
- [fileSecurity](foundation/urlresourcevalues/filesecurity.md)
- [fileSize](foundation/urlresourcevalues/filesize.md)
- [isPurgeable](foundation/urlresourcevalues/ispurgeable.md)
- [isSparse](foundation/urlresourcevalues/issparse.md)
- [mayHaveExtendedAttributes](foundation/urlresourcevalues/mayhaveextendedattributes.md)
- [isExecutable](foundation/urlresourcevalues/isexecutable.md)
- [isRegularFile](foundation/urlresourcevalues/isregularfile.md)
- [mayShareFileContent](foundation/urlresourcevalues/maysharefilecontent.md)
- [totalFileAllocatedSize](foundation/urlresourcevalues/totalfileallocatedsize.md)