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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 mi- nor 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 pro- vides 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), xcb_get_extension_data(3), xdpyinfo(1) AUTHOR Generated from xproto.xml. Contact xcb@lists.freedesktop.org for cor- rections and improvements. X Version 11 libxcb 1.17.0 xcb_query_extension(3)
NAME | SYNOPSIS | REQUEST ARGUMENTS | REPLY FIELDS | DESCRIPTION | RETURN VALUE | ERRORS | SEE ALSO | AUTHOR
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