Hello, misc;
I've been attempting to use OpenBSD libxcb to find the process ID of a window.
The function used to retrieve the PID is as follows:
pid_t
winpid(Window w)
{
pid_t result = 0;
xcb_res_client_id_spec_t spec = {0};
spec.client = w;
spec.mask = XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID;
xcb_res_query_client_ids_cookie_t c =
xcb_res_query_client_ids(xcon, 1, &spec);
xcb_res_query_client_ids_reply_t *r =
xcb_res_query_client_ids_reply(xcon, c, NULL);
if (!r)
return (pid_t)0;
xcb_res_client_id_value_iterator_t i =
xcb_res_query_client_ids_ids_iterator(r);
for (; i.rem; xcb_res_client_id_value_next(&i)) {
spec = i.data->spec;
if (spec.mask & XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID) {
uint32_t *t = xcb_res_client_id_value_value(i.data);
result = *t;
break;
}
}
free(r);
if (result == (pid_t)-1)
result = 0;
return result;
}
The code compiles, however the function returns 0 as a result. I've checked
the value of i.rem; it's always 0. I've made sure that the XCB connection
(represented by xcon) exists.
Has anyone else encountered this error? Thank you in advance.
Ben Raskin.
