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xcb_intern_atom

Section: XCB Requests (3)
Updated: libxcb 1.12
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NAME

xcb_intern_atom - Get atom identifier by name

SYNOPSIS

#include <xcb/xproto.h>

Request function

: xcb_intern_atom_cookie_t xcb_intern_atom(xcb_connection_t *conn, uint8_t only_if_exists, uint16_t name_len, const char *name);

Reply datastructure


typedef struct xcb_intern_atom_reply_t {
    uint8_t    response_type;
    uint8_t    pad0;
    uint16_t   sequence;
    uint32_t   length;
    xcb_atom_t atom;
} xcb_intern_atom_reply_t;

Reply function

: xcb_intern_atom_reply_t *xcb_intern_atom_reply(xcb_connection_t *conn, xcb_intern_atom_cookie_t cookie, xcb_generic_error_t **e);

REQUEST ARGUMENTS

conn: The XCB connection to X11.
only_if_exists: Return a valid atom id only if the atom already exists.
name_len: The length of the following name.
name: The name of the atom.

REPLY FIELDS

response_type: The type of this reply, in this case XCB_INTERN_ATOM. This field is also present in the xcb_generic_reply_t and can be used to tell replies apart from each other.
sequence: The sequence number of the last request processed by the X11 server.
length: The length of the reply, in words (a word is 4 bytes).
atom: TODO: NOT YET DOCUMENTED.

DESCRIPTION

Retrieves the identifier (xcb_atom_t TODO) for the atom with the specified name. Atoms are used in protocols like EWMH, for example to store window titles (_NET_WM_NAME atom) as property of a window.

If only_if_exists is 0, the atom will be created if it does not already exist. If only_if_exists is 1, XCB_ATOM_NONE will be returned if the atom does not yet exist.

RETURN VALUE

Returns an xcb_intern_atom_cookie_t. Errors have to be handled when calling the reply function xcb_intern_atom_reply.

If you want to handle errors in the event loop instead, use xcb_intern_atom_unchecked. See xcb-requests(3) for details.

ERRORS

xcb_alloc_error_t: TODO: reasons?
xcb_value_error_t: A value other than 0 or 1 was specified for only_if_exists.

EXAMPLE


/*
 * Resolves the _NET_WM_NAME atom.
 *
 */
void my_example(xcb_connection_t *c) {
    xcb_intern_atom_cookie_t cookie;
    xcb_intern_atom_reply_t *reply;

    cookie = xcb_intern_atom(c, 0, strlen("_NET_WM_NAME"), "_NET_WM_NAME");
    /* ... do other work here if possible ... */
    if ((reply = xcb_intern_atom_reply(c, cookie, NULL))) {
        printf("The _NET_WM_NAME atom has ID %u, reply->atom);
        free(reply);
    }
}

AUTHOR

Generated from xproto.xml. Contact xcb@lists.freedesktop.org for corrections and improvements.

Index

NAME

SYNOPSIS

Request function
Reply datastructure
Reply function

REQUEST ARGUMENTS