LXR linux/tools/testing/selftests/filesystems/dnotify

   1// SPDX-License-Identifier: GPL-2.0
   2#define _GNU_SOURCE     /* needed to get the defines */
   3#include <fcntl.h>      /* in glibc 2.2 this has the needed
   4                                   values defined */
   5#include <signal.h>
   6#include <stdio.h>
   7#include <unistd.h>
   8
   9static volatile int event_fd;
  10
  11static void handler(int sig, siginfo_t *si, void *data)
  12{
  13        event_fd = si->si_fd;
  14}
  15
  16int main(void)
  17{
  18        struct sigaction act;
  19        int fd;
  20
  21        act.sa_sigaction = handler;
  22        sigemptyset(&act.sa_mask);
  23        act.sa_flags = SA_SIGINFO;
  24        sigaction(SIGRTMIN + 1, &act, NULL);
  25
  26        fd = open(".", O_RDONLY);
  27        fcntl(fd, F_SETSIG, SIGRTMIN + 1);
  28        fcntl(fd, F_NOTIFY, DN_MODIFY|DN_CREATE|DN_MULTISHOT);
  29        /* we will now be notified if any of the files
  30           in "." is modified or new files are created */
  31        while (1) {
  32                pause();
  33                printf("Got event on fd=%d\n", event_fd);
  34        }
  35}
  36