Waiting for the file to appear in Linux using inotify

#include <cstdio>
#include <cstring>
#include <string>
 
#include <unistd.h>
#include <sys/inotify.h>
 
int
main ()
{
    const std::string directory = "/tmp";
    const std::string filename = "test.txt";
    const std::string fullpath = directory + "/" + filename;
 
    int fd = inotify_init ();
    int watch = inotify_add_watch (fd, directory.c_str (),
                                   IN_MODIFY | IN_CREATE | IN_MOVED_TO);
 
    if (access (fullpath.c_str (), F_OK) == 0)
    {
        printf ("File %s exists.\n", fullpath.c_str ());
        return 0;
    }
 
    char buf [1024 * (sizeof (inotify_event) + 16)];
    ssize_t length;
 
    bool isCreated = false;
 
    while (!isCreated)
    {
        length = read (fd, buf, sizeof (buf));
        if (length < 0)
            break;
        inotify_event *event;
        for (size_t i = 0; i < static_cast<size_t> (length);
             i += sizeof (inotify_event) + event->len)
        {
            event = reinterpret_cast<inotify_event *> (&buf[i]);
            if (event->len > 0 && filename == event->name)
            {
                printf ("The file %s was created.\n", event->name);
                isCreated = true;
                break;
            }
        }
    }
 
    inotify_rm_watch (fd, watch);
    close (fd);
}