main.c

#define EVENT_SIZE (sizeof(struct inotify_event))
#define EVENT_BUF_LEN (1024 * (EVENT_SIZE + 16))

int main()
{
    int length, i = 0;
    int fd;
    int wd;
    char buffer[EVENT_BUF_LEN];

    for (;;) {
        /*creating the INOTIFY instance*/
        fd = inotify_init();

        /*checking for error*/
        if (fd < 0) {
            perror("inotify_init");
        }

        /*adding the “/tmp” directory into watch list. Here, the suggestion is to validate the existence of the directory before adding into monitoring list.*/
        wd = inotify_add_watch(fd, "/home/linarcx/test.txt", IN_CREATE | IN_DELETE | IN_MODIFY | IN_CLOSE_WRITE);

        /*read to determine the event change happens on “/tmp” directory. Actually this read blocks until the change event occurs*/

        length = read(fd, buffer, EVENT_BUF_LEN);

        /*checking for error*/
        if (length < 0) {
            perror("read");
        }

        /*actually read return the list of change events happens. Here, read the change event one by one and process it accordingly.*/
        struct inotify_event* event = (struct inotify_event*)&buffer[i];
        if (event->len) {
            if (event->mask & IN_CREATE) {
                if (event->mask & IN_ISDIR) {
                    printf("New directory %s created.\n", event->name);
                } else {
                    printf("New file %s created.\n", event->name);
                }
            } else if (event->mask & IN_DELETE) {
                if (event->mask & IN_ISDIR) {
                    printf("Directory %s deleted.\n", event->name);
                } else {
                    printf("File %s deleted.\n", event->name);
                }
            } else if (event->mask & IN_MODIFY) {
                if (event->mask & IN_ISDIR) {
                    printf("Directory %s deleted.\n", event->name);
                } else {
                    printf("File %s deleted.\n", event->name);
                }
            } else if (event->mask & IN_CLOSE_WRITE) {
                if (event->mask & IN_ISDIR) {
                    printf("Directory %s deleted.\n", event->name);
                } else {
                    printf("File %s deleted.\n", event->name);
                }
            }
        }
        //i += EVENT_SIZE + event->len;
    }
    /*removing the “/tmp” directory from the watch list.*/
    inotify_rm_watch(fd, wd);

    /*closing the INOTIFY instance*/
    close(fd);
}