2 * vim:ts=4:sw=4:expandtab
4 * i3 - an improved dynamic tiling window manager
5 * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
14 #include <xcb/xcb_aux.h>
19 * Try to get the contents of the given atom (for example I3_SOCKET_PATH) from
20 * the X11 root window and return NULL if it doesn’t work.
22 * The memory for the contents is dynamically allocated and has to be
23 * free()d by the caller.
26 char *root_atom_contents(const char *atomname) {
27 xcb_connection_t *conn;
28 xcb_intern_atom_cookie_t atom_cookie;
29 xcb_intern_atom_reply_t *atom_reply;
33 if ((conn = xcb_connect(NULL, &screen)) == NULL ||
34 xcb_connection_has_error(conn))
37 atom_cookie = xcb_intern_atom(conn, 0, strlen(atomname), atomname);
39 xcb_screen_t *root_screen = xcb_aux_get_screen(conn, screen);
40 xcb_window_t root = root_screen->root;
42 atom_reply = xcb_intern_atom_reply(conn, atom_cookie, NULL);
43 if (atom_reply == NULL)
46 xcb_get_property_cookie_t prop_cookie;
47 xcb_get_property_reply_t *prop_reply;
48 prop_cookie = xcb_get_property_unchecked(conn, false, root, atom_reply->atom,
49 XCB_GET_PROPERTY_TYPE_ANY, 0, PATH_MAX);
50 prop_reply = xcb_get_property_reply(conn, prop_cookie, NULL);
51 if (prop_reply == NULL || xcb_get_property_value_length(prop_reply) == 0)
53 if (prop_reply->type == XCB_ATOM_CARDINAL) {
54 /* We treat a CARDINAL as a >= 32-bit unsigned int. The only CARDINAL
55 * we query is I3_PID, which is 32-bit. */
56 if (asprintf(&content, "%u", *((unsigned int*)xcb_get_property_value(prop_reply))) == -1)
59 if (asprintf(&content, "%.*s", xcb_get_property_value_length(prop_reply),
60 (char*)xcb_get_property_value(prop_reply)) == -1)