How to read large file by range in objective-c?

Question

I want to read a large file in objective-c, and used in iphone development I used the follow code

NSData *data = [[NSData alloc] initWithContentsOfFile:file];
unsigned char *readData[2000];
[data getBytes:readData range:NSMakeRange(1000,3000)]

This maybe get the iphone app crash, because the size of the file is large.

I tried to use NSInputStream, but I can't find the range parameter in any method, can anyone give a help?

Thanks & Best Regards Timmy

Answer 1

Use NSFileHandle : Seek to the offset where your data starts and start reading from there.

NSFileHandle *fileHandle = [NSFileHandle fileHandleForReadingAtPath:filePath];
[fileHandle seekToFileOffset:1000];
NSData *data = [fileHandle readDataOfLength:2000];