Sunday, May 12, 2013

NSInputStream inputStreamWithFileAtPath example ios


Creates and returns an initialized NSInputStream object that reads data from the file at a given path.
+ (id)inputStreamWithFileAtPath:(NSString *)path
The path to the file.
Return Value( NSInputStream inputStreamWithFileAtPath example )
An initialized NSInputStream object that reads data from the file at path. If the file specified by pathdoesn’t exist or is unreadable, returns nil.
( NSInputStream inputStreamWithFileAtPath example )
NSString* fileName = [[NSBundle mainBundle] pathForResource:@"resource" ofType:@".dat"];
NSInputStream* dataStream = [NSInputStream inputStreamWithFileAtPath:fileName];
if (dataStream == nil) {
    NSLog(@"load asset failed");

[dataStream setDelegate:self];
[dataStream scheduleInRunLoop:[NSRunLoop currentRunLoop]
[dataStream open];
( NSInputStream inputStreamWithFileAtPath example )
        // Open a stream for the file we're going to send.  We do not open this stream; 
        // NSURLConnection will do it for us.

        self.fileStream = [NSInputStream inputStreamWithFileAtPath:localFilePath];
        assert(self.fileStream != nil);

        [self.fileStream open];

        // Open a CFFTPStream for the URL.

        self.networkStream = CFBridgingRelease(
                                               CFWriteStreamCreateWithFTPURL(NULL, ( CFURLRef) url)
        assert(self.networkStream != nil);

        // if ([self.usernameText.text length] != 0) {
        success = [self.networkStream setProperty:@"yourUserName" forKey:(id)kCFStreamPropertyFTPUserName];
        success = [self.networkStream setProperty:@"yourPassword" forKey:(id)kCFStreamPropertyFTPPassword];

        self.networkStream.delegate = self;
        [self.networkStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
        [self.networkStream open];

        // Tell the UI we're sending.

        [self sendDidStart];
( NSInputStream inputStreamWithFileAtPath example )
// Make sure that this number is larger than the header + 1 block.
// 33+16 bytes = 49 bytes. So it shouldn't be a problem.
int blockSize = 32 * 1024;

NSInputStream *cryptedStream = [NSInputStream inputStreamWithFileAtPath:@"C++ Spec.pdf"];
NSOutputStream *decryptedStream = [NSOutputStream outputStreamToFileAtPath:@"/tmp/C++.crypt" append:NO];

[cryptedStream open];
[decryptedStream open];

// We don't need to keep making new NSData objects. We can just use one repeatedly.
__block NSMutableData *data = [NSMutableData dataWithLength:blockSize];
__block RNEncryptor *decryptor = nil;

dispatch_block_t readStreamBlock = ^{
  [data setLength:blockSize];
  NSInteger bytesRead = [cryptedStream read:[data mutableBytes] maxLength:blockSize];
  if (bytesRead < 0) {
    // Throw an error
  else if (bytesRead == 0) {
    [decryptor finish];
  else {
    [data setLength:bytesRead];
    [decryptor addData:data];
    NSLog(@"Sent %ld bytes to decryptor", (unsigned long)bytesRead);

decryptor = [[RNEncryptor alloc] initWithSettings:kRNCryptorAES256Settings
                                          handler:^(RNCryptor *cryptor, NSData *data) {
                                            NSLog(@"Decryptor recevied %ld bytes", (unsigned long)data.length);
                                            [decryptedStream write:data.bytes maxLength:data.length];
                                            if (cryptor.isFinished) {
                                              [decryptedStream close];
                                              // call my delegate that I'm finished with decrypting
                                            else {
                                              // Might want to put this in a dispatch_async(), but I don't think you need it.

// Read the first block to kick things off