gri3-wm/libi3/root_atom_contents.c

67 lines
2.1 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* vim:ts=4:sw=4:expandtab
*
* i3 - an improved dynamic tiling window manager
* © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
*
*/
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <limits.h>
#include <xcb/xcb.h>
#include <xcb/xcb_aux.h>
#include "libi3.h"
/*
* Try to get the contents of the given atom (for example I3_SOCKET_PATH) from
* the X11 root window and return NULL if it doesnt work.
*
* The memory for the contents is dynamically allocated and has to be
* free()d by the caller.
*
*/
char *root_atom_contents(const char *atomname) {
xcb_connection_t *conn;
xcb_intern_atom_cookie_t atom_cookie;
xcb_intern_atom_reply_t *atom_reply;
int screen;
char *content;
if ((conn = xcb_connect(NULL, &screen)) == NULL ||
xcb_connection_has_error(conn))
return NULL;
atom_cookie = xcb_intern_atom(conn, 0, strlen(atomname), atomname);
xcb_screen_t *root_screen = xcb_aux_get_screen(conn, screen);
xcb_window_t root = root_screen->root;
atom_reply = xcb_intern_atom_reply(conn, atom_cookie, NULL);
if (atom_reply == NULL)
return NULL;
xcb_get_property_cookie_t prop_cookie;
xcb_get_property_reply_t *prop_reply;
prop_cookie = xcb_get_property_unchecked(conn, false, root, atom_reply->atom,
XCB_GET_PROPERTY_TYPE_ANY, 0, PATH_MAX);
prop_reply = xcb_get_property_reply(conn, prop_cookie, NULL);
if (prop_reply == NULL || xcb_get_property_value_length(prop_reply) == 0)
return NULL;
if (prop_reply->type == XCB_ATOM_CARDINAL) {
/* We treat a CARDINAL as a >= 32-bit unsigned int. The only CARDINAL
* we query is I3_PID, which is 32-bit. */
if (asprintf(&content, "%u", *((unsigned int*)xcb_get_property_value(prop_reply))) == -1)
return NULL;
} else {
if (asprintf(&content, "%.*s", xcb_get_property_value_length(prop_reply),
(char*)xcb_get_property_value(prop_reply)) == -1)
return NULL;
}
xcb_disconnect(conn);
return content;
}