---
layout: docs
title: isSigned
id: class.Facebook.HackCodegen.SignedSourceBase.isSigned
docid: class.Facebook.HackCodegen.SignedSourceBase.isSigned
permalink: /docs/reference/class.Facebook.HackCodegen.SignedSourceBase.isSigned/
---
# Facebook\\HackCodegen\\SignedSourceBase::isSigned()




Determine if a file is signed or not




``` Hack
public static function isSigned(
  string $file_data,
): bool;
```




This does NOT verify the signature.




@param  string  File data.
@return bool    True if the file has a signature.




## Parameters




- ` string $file_data `




## Returns




+ ` bool `