# readInto:startingAt:length:error: Synchronously reads data from the resource into a buffer. ``` - (size_t) readInto:(void *) buffer startingAt:(off_t) offset length:(size_t) length error:(NSError **) error; ``` ## Parameters `buffer` A buffer to receive the data. `offset` The offset into the resource from which to start reading. `length` A maximum number of bytes to read. The method’s return value contains the actual number of bytes read. `error` On return, any error encountered while reading data, or `nil` if no error occurred. ## Return Value The actual number of bytes read. ## Discussion This is a synchronous version of [`readInto:startingAt:length:completionHandler:`](/documentation/FSKit/FSBlockDeviceResource/readInto:startingAt:length:completionHandler:). > Note: In some cases, this method performs a partial read. In this case, the return value is shorter than the requested length, and the `error` is set to `nil`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)