LXR linux/Documentation/filesystems/dnotify

   1#define _GNU_SOURCE     /* needed to get the defines */
   2#include <fcntl.h>      /* in glibc 2.2 this has the needed
   3                                   values defined */
   4#include <signal.h>
   5#include <stdio.h>
   6#include <unistd.h>
   7
   8static volatile int event_fd;
   9
  10static void handler(int sig, siginfo_t *si, void *data)
  11{
  12        event_fd = si->si_fd;
  13}
  14
  15int main(void)
  16{
  17        struct sigaction act;
  18        int fd;
  19
  20        act.sa_sigaction = handler;
  21        sigemptyset(&act.sa_mask);
  22        act.sa_flags = SA_SIGINFO;
  23        sigaction(SIGRTMIN + 1, &act, NULL);
  24
  25        fd = open(".", O_RDONLY);
  26        fcntl(fd, F_SETSIG, SIGRTMIN + 1);
  27        fcntl(fd, F_NOTIFY, DN_MODIFY|DN_CREATE|DN_MULTISHOT);
  28        /* we will now be notified if any of the files
  29           in "." is modified or new files are created */
  30        while (1) {
  31                pause();
  32                printf("Got event on fd=%d\n", event_fd);
  33        }
  34}
  35