inotify API with select

I am trying to use inotify with a select() call.

The time_out is set at 3 secs. I cannot seem to get it to work.

The select always returns zero.

Code snippet,

    fd_set fds;

    //fd is descriptor for inotify_init
    FD_ZERO(&fds);
    FD_SET(fd, &fds);

    struct timeval time_wait;
    while(true)
    {
            time_wait.tv_sec=3;
            time_wait.tv_usec=0;
            i = 0;
            res = select(fd , &fds, NULL, NULL, &time_wait);

            if (ret == -1) {
                    printf("Error occured in inotify read \n");
                    break;
            }

            if(ret == 0) {         
                    //always triggers
                    printf("timed out \n");
                    continue;
            }

            //Never reaches here
            printf("Event occured \n");
            ......
    }

If I do not use select, it works fine. And it also works well with poll().

I also tried inotify_init1() with IN_NONBLOCK

Can someone tell what I'm doing wrong?

First of all, the first argument to select is the highest descriptor in any set plus one. So in your case it should be fd + 1.

Secondly, the select function modifies the sets, so you need to add the descriptors every iteration in the loop.