Instance Method

readDataOfLength:

Synchronously reads data up to the specified number of bytes.

Declaration

- (NSData *)readDataOfLength:(NSUInteger)length;

Parameters

length

The number of bytes to read from the receiver.

Return Value

The data available through the receiver up to a maximum of length bytes, or the maximum size that can be represented by an NSData object, whichever is the smaller.

Discussion

If the receiver is a file, this method returns the data obtained by reading length bytes starting at the current file pointer. If length bytes are not available, this method returns the data from the current file pointer to the end of the file. If the receiver is a communications channel, the method reads up to length bytes from the channel. Returns an empty NSData object if the file is positioned at the end of the file or if an end-of-file indicator is returned on a communications channel. This method raises NSFileHandleOperationException if attempts to determine the file-handle type fail or if attempts to read from the file or channel fail.

See Also

Reading from a File Handle

availableData

The data currently available in the receiver.

- readDataToEndOfFile

Synchronously reads the available data up to the end of file or maximum number of bytes.