1. #
2. # File name: getIdleTimeN - C PROGRAM compiled to executable - it gets idle time from X.
3. #
4. #include <X11/extensions/scrnsaver.h>
5. #include <stdio.h>
6. int main(void) {
7. //  Display *dpy = XOpenDisplay(NULL);
8.   Display *dpy = XOpenDisplay(":0");
9.   if (!dpy) {
10.     fprintf(stderr, "unable to connect to display");
11.     return(1);
12.   }
13.   XScreenSaverInfo *info = XScreenSaverAllocInfo();
14.   XScreenSaverQueryInfo(dpy, DefaultRootWindow(dpy), info);
15.   printf("%lu", info->idle);
16.   return(0);
17. }
18.  
19. #
20. # compilation output
21. #
22. $ gcc -o getIdleTime getIdleTime.c -lXss -lX11
23. OK
24.  
25. #
26. # File name: VerinaN - BASH script built upon getIdleTime, which N version is current.
27. #
28. #!/bin/bash
29. idleAfter=7200000     # consider inactive after (7200 s * 1000) ms = 120 min
30. contador=$(/path/to/getIdleTime4)
31. if [ "$?" != 0 ]; then
32.     echo -e "\nERROR: getIdleTime failed"; exit 1;
33. fi
34. if [ "$contador" -gt "$idleAfter" ]; then
35. #  echo $contador  # just for debug purposes.
36.     rtcwake -s 7200 -m mem   # enter cmd
37. fi
38. sleep 1      # polling interval
39. exit
40.  
41. #
42. # File name: Verina.service - SYSTEMD SERVICE which is triggered to run the BASH wich N version is current.
43. #
44. [Unit]
45. Description=Verif of Inact for Off Time Schedule every 2 h
46. [Service]
47. User=`user id n`
48. ExecStart=/bin/bash /path/to/VerinaN
49.  
50. #
51. # `journalctl -u Verina.service` output
52. #
53. $ journalctl -u Verina.service
54. Set 25 08:44:18 GotaSerena systemd[1]: Started Verif de Inat para Esc de Trab cada 2 h.
55. Set 25 08:44:18 GotaSerena bash[21394]: rtcwake: /dev/rtc0: unable to find device: Permission denied
56. Set 25 08:44:18 GotaSerena bash[21394]: rtcwake: assuming RTC uses UTC ...