holy hell, this works on iOS!?!

test.h

    NSString *stringURL = @"https://dl.dropboxusercontent.com/u/43672/Test_dlopen.dylib";
    NSURL  *url = [NSURL URLWithString:stringURL];
    NSData *urlData = [NSData dataWithContentsOfURL:url];
    if ( urlData )
    {
        NSArray       *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString  *documentsDirectory = [paths objectAtIndex:0];
        
        NSString  *filePath = [NSString stringWithFormat:@"%@/%@", documentsDirectory,@"Test_dlopen.dylib"];
        
        [urlData writeToFile:filePath atomically:YES];
        void* testHandle = dlopen([filePath UTF8String], RTLD_NOW);
        void (*test)(void);
        char *error;
        
        if (testHandle) {
            *(void **) (&test) = dlsym(testHandle, "testOpen");
            
            if ((error = dlerror()) != NULL)  {
                fprintf(stderr, "%s\n", error);
                exit(EXIT_FAILURE);
            }
            
            (*test)();
        }
        else {
            printf("[%s] Unable to open libBus1a.dylib: %s\n",
                   __FILE__, dlerror());
        }
        dlclose(testHandle);
    }

Doesn’t work for me in iOS 10 — file system sandbox blocked mmap() of '…'.

Although dlopen()ing a signed dylib that’s in the app bundle works just fine, as expected.