---
title: "read(fromAbsoluteOffset:into:retryOnInterrupt:)"
framework: system
role: symbol
role_heading: Instance Method
path: "system/filedescriptor/read(fromabsoluteoffset:into:retryoninterrupt:)"
---

# read(fromAbsoluteOffset:into:retryOnInterrupt:)

Reads bytes at the specified offset into a buffer.

## Declaration

```swift
func read(fromAbsoluteOffset offset: Int64, into buffer: UnsafeMutableRawBufferPointer, retryOnInterrupt: Bool = true) throws -> Int
```

## Parameters

- `offset`: The file offset where reading begins.
- `buffer`: The region of memory to read into.
- `retryOnInterrupt`: Whether to retry the read operation if it throws doc://com.apple.SwiftSystem/documentation/System/Errno/interrupted. The default is true. Pass false to try only once and throw an error upon interruption.

## Mentioned in

Adopting Swift File Operations

## Return Value

Return Value The number of bytes that were read.

## Discussion

Discussion The doc://com.apple.documentation/documentation/swift/unsafemutablerawbufferpointer/count-95usp property of buffer determines the maximum number of bytes that are read into that buffer. Unlike read(into:retryOnInterrupt:), this method leaves the file’s existing offset unchanged. The corresponding C function is pread.

## See Also

### Reading From a File

- [read(into:retryOnInterrupt:)](system/filedescriptor/read(into:retryoninterrupt:).md)