xcb_query_extension(3)						   XCB Requests 					    xcb_query_extension(3)

NAME

       xcb_query_extension - check if extension is present

SYNOPSIS

       #include <xcb/xproto.h>

   Request function
       xcb_query_extension_cookie_t xcb_query_extension(xcb_connection_t *conn, uint16_t name_len, const char *name);

   Reply datastructure
       typedef struct xcb_query_extension_reply_t {
	   uint8_t  response_type;
	   uint8_t  pad0;
	   uint16_t sequence;
	   uint32_t length;
	   uint8_t  present;
	   uint8_t  major_opcode;
	   uint8_t  first_event;
	   uint8_t  first_error;
       } xcb_query_extension_reply_t;

   Reply function
       xcb_query_extension_reply_t *xcb_query_extension_reply(xcb_connection_t *conn, xcb_query_extension_cookie_t cookie,
	      xcb_generic_error_t **e);

REQUEST ARGUMENTS

       conn	 The XCB connection to X11.

       name_len  The length of name in bytes.

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

REPLY FIELDS

       response_type
		 The type of this reply, in this case XCB_QUERY_EXTENSION. 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).

       present	 Whether the extension is present on this X11 server.

       major_opcode
		 The major opcode for requests.

       first_event
		 The first event code, if any.

       first_error
		 The first error code, if any.

DESCRIPTION

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

       Every extension has a unique major_opcode to identify requests, the minor opcodes and request formats are extension-specific. If the exten-
       sion provides events and errors, the first_event and first_error fields in the reply are set accordingly.

       There should rarely be a need to use this request directly, XCB provides the xcb_get_extension_data function instead.

RETURN VALUE

       Returns an xcb_query_extension_cookie_t. Errors have to be handled when calling the reply function xcb_query_extension_reply.

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

ERRORS

       This request does never generate any errors.

SEE ALSO

       xcb-requests(3), xdpyinfo(1), xcb_get_extension_data(3)

AUTHOR

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

XCB
								    2014-06-10						    xcb_query_extension(3)