write file to document directory

NSData *data=[[NSData alloc]initWithContentsOfFile:[[NSBundle mainBundle]pathForResource:@"tamil.txt" ofType:nil] encoding:NSUTF8StringEncoding error:nil]; 

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentDirectory = [paths objectAtIndex:0];

NSString *writePath=[documentDirectory stringByAppendingPathComponent:@"tamil.txt"];

[data writeToFile: writePath atomically:YES];