/* gcc -o xidletime xidletime.c -lXext -lX11 */
#include <X11/Xlib.h>
#include <X11/extensions/sync.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <inttypes.h>

int main(void)
{
    Display *dpy;
    int i, event, error, count;
    XSyncSystemCounter *sys;
    XSyncValue val;

    dpy = XOpenDisplay(NULL);
    if (!dpy)
	return 1;

    if (!XSyncQueryExtension(dpy, &event, &error))
	return 1;

    sys = XSyncListSystemCounters(dpy, &count);

    for (i = 0; i < count; i++)
	if (!strcmp(sys[i].name, "IDLETIME")) {
	    uint64_t v;
	    XSyncQueryCounter(dpy, sys[i].counter, &val);
	    v = ((uint64_t)XSyncValueHigh32(val) << 32) | XSyncValueLow32(val);
	    printf("%" PRIu64 "\n", v);
	}

    return 0;
}