Example of creating a simple container for binary files, and parsing it

- (void)demonstrateCustomBinaryDataParsing
{
	// Generate data in the format:
	// name:size\n<data>name:size\n<data>
	
	NSData *file1data = [NSData dataWithContentsOfFile:@"/Users/ben/Desktop/1.png"];
	NSData *file2data = [NSData dataWithContentsOfFile:@"/Users/ben/Desktop/2.png"];
	NSMutableData *payload = [NSMutableData data];
	NSLog([NSString stringWithFormat:@"file1:%lu\n",[file1data length]]);
	[payload appendData:[[NSString stringWithFormat:@"file1:%lu\n",[file1data length]] dataUsingEncoding:NSASCIIStringEncoding]];
	[payload appendData:file1data];
	[payload appendData:[[NSString stringWithFormat:@"file2:%lu\n",[file2data length]] dataUsingEncoding:NSASCIIStringEncoding]];
	[payload appendData:file2data];
	
	// Parse the data to get the files back out
	
	const char *bytes = [payload bytes];
	unsigned int length = [payload length];
	
	unsigned int lastHeaderStartByte = 0;
	
	NSMutableArray *files = [NSMutableArray array];
	NSMutableDictionary *currentFile = [NSMutableDictionary dictionary];
	unsigned int readByte = 0;
	
	while (readByte < length) {
		if (bytes[readByte] == *"\n") {
			void *header = calloc(readByte+1-lastHeaderStartByte,1);
			[payload getBytes:header range:NSMakeRange(lastHeaderStartByte,readByte)];
			NSArray *headerStringArray = [[NSString stringWithCString:header encoding:NSASCIIStringEncoding] componentsSeparatedByString:@":"];
			[currentFile setObject:[headerStringArray objectAtIndex:0] forKey:@"name"];
			unsigned long long length = [[headerStringArray objectAtIndex:1] longLongValue];
			free(header);
			
			char *data = malloc(length);
			[payload getBytes:data range:NSMakeRange(readByte+1,length)];
			[currentFile setObject:[NSData dataWithBytes:data length:length] forKey:@"data"];
			lastHeaderStartByte = readByte+1+length;
			readByte = lastHeaderStartByte;
			free(data);
			[files addObject:currentFile];
			currentFile = [NSMutableDictionary dictionary];
		}
			
		readByte++;
	}
	UIImage *image = [UIImage imageWithData:[[files objectAtIndex:0] objectForKey:@"data"]];
	UIImage *image2 = [UIImage imageWithData:[[files objectAtIndex:1] objectForKey:@"data"]];				  
	
}