xcbqueryextension(3) XCB Requests xcbqueryextension(3)

NAME
       xcbqueryextension - check if extension is present

SYNOPSIS
       #include 

   Request function
       xcbqueryextensioncookiet
              xcbqueryextension(xcbconnectiont *conn, uint16t namelen,
              const char *name);

   Reply datastructure
       typedef struct xcbqueryextensionreplyt {
           uint8t  responsetype;
           uint8t  pad0;
           uint16t sequence;
           uint32t length;
           uint8t  present;
           uint8t  majoropcode;
           uint8t  firstevent;
           uint8t  firsterror;
       } xcbqueryextensionreplyt;

   Reply function
       xcbqueryextensionreplyt
              *xcbqueryextensionreply(xcbconnectiont *conn,
              xcbqueryextensioncookiet cookie, xcbgenericerrort **e);

REQUEST ARGUMENTS
       conn      The XCB connection to X11.

       namelen  The length of name in bytes.

       name      The name of the extension to query, for example "RANDR". This
                 is case sensitive!

REPLY FIELDS
       responsetype
                 The type of this reply, in this case XCBQUERYEXTENSION.
                 This field is also present in the xcbgenericreplyt 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).

       present   Whether the extension is present on this X11 server.

       majoropcode
                 The major opcode for requests.

       firstevent
                 The first event code, if any.

       firsterror
                 The first error code, if any.

DESCRIPTION
       Determines if the specified extension is present on this X11 server.

       Every extension has a unique majoropcode to identify requests, the mi‐
       nor opcodes and request formats are extension-specific. If the exten‐
       sion provides events and errors, the firstevent and firsterror fields
       in the reply are set accordingly.

       There should rarely be a need to use this request directly, XCB pro‐
       vides the xcbgetextensiondata function instead.

RETURN VALUE
       Returns an xcbqueryextensioncookiet. Errors have to be handled when
       calling the reply function xcbqueryextensionreply.

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

ERRORS
       This request does never generate any errors.

SEE ALSO
       xcb-requests(3), xcbgetextensiondata(3), xdpyinfo(1)

AUTHOR
       Generated from xproto.xml. Contact xcb@lists.freedesktop.org for cor‐
       rections and improvements.



X Version 11                      libxcb 1.13           xcbqueryextension(3)