#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>

#include <X11/Xlib.h>
#include <X11/extensions/Xinerama.h>

int main(int argc, char **argv)
{
    Display *dpy;
    XineramaScreenInfo *xsi;
    int i, nscreens;

    dpy = XOpenDisplay(NULL);
    if (dpy == NULL) {
        fputs("ERROR: Could not open display!\n", stderr);
        return EXIT_FAILURE;
    }

    /* Is xinerama extension available? */
    if (!XineramaIsActive(dpy)) {
        fputs("ERROR: Xinerama extension unavailable on current screen!\n", stderr);
        return EXIT_FAILURE;
    }
    else {
	xsi = XineramaQueryScreens(dpy, &nscreens);

	if (argc <= 1) {	
	    for (i = 0; i < nscreens; i++) {
		printf("screen %d: %dx%d\n", i, xsi[i].width, xsi[i].height);
	    }
	}
	else {
	    i = atoi(argv[1]);
	    if (i <= 0 || i > nscreens) {
		fprintf(stderr, "ERROR: Screen %d not available!\n", i);
	        return EXIT_FAILURE;
	    }
	    else
		printf("%dx%d\n", xsi[i-1].width, xsi[i-1].height);
	}
    }

    return EXIT_SUCCESS;
}