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 
8 static volatile int event_fd;
9 
10 static void handler(int sig, siginfo_t *si, void *data)
11 {
12 	event_fd = si->si_fd;
13 }
14 
15 int 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