Detect Folder Access in Objective C or C++ on OSX (Like fs_usage command)

Question

I\'m working on a realtime virus scanner on OSX. The OSX\'s command line command fs_usage can be used to determine folder access in the following way (and can only

Answer 1

The following code must be in a main.m and not a main.mm or it won't compile. (SEE ADDENDUM BELOW for C++ (main.mm).) The following code runs in a loop, watching new file creations in /Users/mike/Documents and /Users/mike/Downloads. (Sorry, it doesn't support wildcards on those paths -- I wish it did!) Press CTRL+C to exit the run loop.

Note in the output, if you download a file, you'll see a consistent flag ID of 125184. If a new file is copied into a folder from the same folder, the flag ID is 128256. If a new file is created fresh (like from an editor), the flag ID is 108544. If an existing file is dragged into a folder, the flag ID is 67584. You'll need to keep experimenting with IDs to see what events you want to trap. For instance, if coding a real-time virus scanner, you'd probably want to detect files moved either by command line, drag and drop, cut/paste, or downloaded from the web to a particular folder. Try various scenarios and subfolders, see the IDs you get, and write code that traps those flag IDs.

#import 

void detectNewFile (
    ConstFSEventStreamRef streamRef,
    void *clientCallBackInfo,
    size_t numEvents,
    void *eventPaths,
    const FSEventStreamEventFlags eventFlags[],
    const FSEventStreamEventId eventIds[])
{
    int i;
    char **paths = eventPaths;

    printf("GOT AN EVENT!!!!\n");
    for (i=0; i

Addendum

If you need this to work with main.mm and thus C++, you need to add CoreServices.framework library to the build steps. Then, change this line:

char **paths = eventPaths;

...to this line:

char **paths = (char **)eventPaths;

Then change this line:

void *callbackInfo = NULL;

...to this line:

FSEventStreamContext *callbackInfo = NULL;

Then change this line:

CFAbsoluteTime latency = 1.0; // seconds

...to this line:

CFTimeInterval latency = 1.0; // seconds