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# readDataToEndOfFile()

Reads the available data synchronously up to the end of file or maximum number of bytes.

```
func readDataToEndOfFile() -> Data
```

## Return Value

The data available through the receiver up to maximum size that can be represented by an [`NSData`](/documentation/Foundation/NSData) object or, if a communications channel, until an end-of-file indicator is returned.

## Discussion

This method invokes [`readData(ofLength:)`](/documentation/Foundation/FileHandle/readData(ofLength:)) as part of its implementation.

> Important:
> This method raises ``doc://com.apple.foundation/documentation/Foundation/NSExceptionName/fileHandleOperationException`` if attempts to determine the file-handle type fail or if attempts to read from the file or channel fail.

## See Also

[`availableData`](/documentation/Foundation/FileHandle/availableData)

The data currently available in the receiver.


---

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