Copy file from bundle to documents directory in iOS

gistfile1.txt

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.filename = @"file.ext";
    
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentDir = [documentPaths objectAtIndex:0];
    self.filePath = [documentDir stringByAppendingPathComponent:self.filename];
    
    [self createAndCheckDatabase];

    // Override point for customization after application launch.
    return YES;
}
        
- (void)createAndCheckDatabase
{
    BOOL success; 
    
    NSFileManager *fileManager = [NSFileManager defaultManager];
    success = [fileManager fileExistsAtPath:filePath];
    
    if (success) return; 
    
    NSString *filePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:self.filename];
    
    [fileManager copyItemAtPath:filePathFromApp toPath:filePath error:nil];
}