Well I am trying to creating a simple tool to read an specific offset address from a file that's within the project.
I can read it fine and get the bytes, the problem is that I want to convert the result into a string, but I just can't.
My output is this: <00000100 88000d00 02140dbb 05c3a282> but I want into String.
Found some examples of doing it using an extension for NSData, but still didn't work.
So anyone could help??
Here's my code:
class ViewController: UIViewController {
let filemgr = NSFileManager.defaultManager()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let pathToFile = NSBundle.mainBundle() .pathForResource("control", ofType: "bin")
let databuffer = filemgr.contentsAtPath(pathToFile!)
let file: NSFileHandle? = NSFileHandle(forReadingAtPath: pathToFile!)
if file == nil {
println("File open failed")
} else {
file?.seekToFileOffset(197584)
let byte = file?.readDataOfLength(16)
println(byte!)
file?.closeFile()
}
}
}
So long as you know the encoding, you can create a string from an NSData
object like this
let str = NSString(data: data, encoding: NSUTF8StringEncoding)
By the way, you might want to try using if let
to unwrap your optionals rather than force-unwrapping, to account for failure possibilities:
let filemgr = NSFileManager.defaultManager()
if let pathToFile = NSBundle.mainBundle() .pathForResource("control", ofType: "bin"),
databuffer = filemgr.contentsAtPath(pathToFile),
file = NSFileHandle(forReadingAtPath: pathToFile)
{
file.seekToFileOffset(197584)
let bytes = file.readDataOfLength(16)
let str = NSString(data: bytes, encoding: NSUTF8StringEncoding)
println(str)
file.closeFile()
}
else {
println("File open failed")
}
The correct answer following @Martin R suggestion to this link: https://codereview.stackexchange.com/a/86613/35991
Here's the code:
extension NSData {
func hexString() -> String {
// "Array" of all bytes:
let bytes = UnsafeBufferPointer<UInt8>(start: UnsafePointer(self.bytes), count:self.length)
// Array of hex strings, one for each byte:
let hexBytes = map(bytes) { String(format: "%02hhx", $0) }
// Concatenate all hex strings:
return "".join(hexBytes)
}
}
And I used like this:
let token = byte.hexString()
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