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Can anyone suggest a method to read bytes from NSData (like read function in @interface NSInputStream : NSStream)
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NSData provides methods for atomically saving their contents to a file, which guarantee that the data is either saved in its entirety, or it fails completely. An atomic write first writes the data to a temporary file and then, only if this write succeeds, moves the temporary file to its final location.
From Apple's documentation: NSData and its mutable subclass NSMutableData provide data objects, object-oriented wrappers for byte buffers. Data objects let simple allocated buffers (that is, data with no embedded pointers) take on the behavior of Foundation objects.
In Swift a byte is called a UInt8—an unsigned 8 bit integer. A byte array is a UInt8 array. In ASCII we can treat chars as UInt8 values. With the utf8 String property, we get a UTF8View collection. We can convert this to a byte array.
How to read binary bytes in NSData? may help you:
NSString *path = @"…put the path to your file here…";
NSData * fileData = [NSData dataWithContentsOfFile: path];
const char* fileBytes = (const char*)[fileData bytes];
NSUInteger length = [fileData length];
NSUInteger index;
for (index = 0; index<length; index++) {
char aByte = fileBytes[index];
//Do something with each byte
}
You can also create an NSInputStream from an NSData object, if you need the read interface:
NSData *data = ...;
NSInputStream *readData = [[NSInputStream alloc] initWithData:data];
[readData open];
However, you should be aware that initWithData copies the contents of data.
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