xcbtest.c

#include <xcb/xcb.h>
#include <stdio.h>

/*
gcc -o xcbtest xcbtest.c -lxcb
*/ 

int main() {
    int i = -1;
    xcb_connection_t *c;
    do {
     c = xcb_connect(NULL, NULL);
     putc('.', stderr);
     i++;
    } while (!xcb_connection_has_error(c));
    fprintf(stderr, "\n\n%d connections\n\n", i);
}