Question

I need to put separate lines into a file, but it seems that it’s not supported by

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    // the path to write file
    NSString *appFile = [documentsDirectory stringByAppendingPathComponent:@"myFile"];

    [dataString writeToFile:appFile atomically:YES];

It does put a string to a file but it overwrites previous one.

Any suggestions?

Answer 1

To append data to an existing file, create an NSFileHandle instance for that file, then call -seekToEndOfFile and finally -writeData:. You’ll have to convert your string into an NSData object yourself (with the correct encoding). And don’t forget to close the file handle when you’re finished.

The easier, but also less efficient way, is to read the existing file contents into a string, then append the new text to that string and write everything out to disk again. I wouldn’t do that in a loop that executes 2000 times, though.