Parsing textfile to NSTextview and keep updates

Hi everyone

I have a problem with something that should be fairly simple. I have a C++ background and did similar things in C++/STL and the Win32 APi, but I can't get very far in Cocoa and Objective C.

What I want to do is read a log file line by line, check for keywoards (such as INFO, ERROR, WARNING) in each line, and color the full line accordingly. Also the logfile updates frequently and it would be costly (i think) to read the whole file over and over again, so something like the terminal "tail -f" command would be good (though this is for a later stage of the project).

My code now is as such:

NSTextStorage *ts;
    NSArray *lines;
    NSAttributedString *line;
   
    // store the textstorage of the textview
    ts = [textView textStorage];
   
    // load the file into an array
    lines = [[NSString stringWithContentsOfFile:@"/Volumes/data/Users/jeroenb/Library/Preferences/Macromedia/Flash Player/Logs/flashlog.txt"] componentsSeparatedByString:@"\n"];

    // create attributes for the strings   
    NSFont *font = [NSFont fontWithName:@"Monaco" size:14.0];
    NSMutableDictionary *attrsDictionary =    [NSMutableDictionary dictionaryWithObject:font    forKey:NSFontAttributeName];
    [attrsDictionary setObject: [NSColor blackColor] forKey: NSForegroundColorAttributeName];
   
    // loop the file and add the strings to the textstorage
    for (NSString *element in lines) {
        line = [[NSAttributedString alloc] initWithString:element attributes:attrsDictionary];
        [ts appendAttributedString:line];   
    }

It works to load the file, and eventually I have a NSTextview with all the text (but all on one line :( newlines are lost) and it already takes a long time to do this (so I am thinking I do it very wrong, it takes about 1 second to parse the file, which is only about 10kb);

Furthermore, I have no clue on how to search the line string properply and setting the colour, though this can be found in the documentation I am sure. I have more problems with the newlines that are gone and the slow appending to the textstorage.

Hopefully it is clear what I want to do, it's so basic and simple, and still I can't doing, even after digging into the xcode cocoa/objective c documentation.

Thank you already!

PS: the log file is something like:
[11:31:00 - INFO new app inited
[11:31:05 - INFO] engine started
[11:31:07 - WARNING] engine assets not found
[11:31:12 - ERROR] asset 'background.png' is null

And it should become in the textview
[11:31:00 - INFO new app inited (blue line)
[11:31:05 - INFO] engine started (blue line)
[11:31:07 - WARNING] engine assets not found (yellow line)
[11:31:12 - ERROR] asset 'background.png' is null (red line)