XQueryExtension(3)         X FUNCTIONS         XQueryExtension(3)



NAME
       XQueryExtension,   XListExtensions,  XFreeExtensionList  -
       list available extensions

SYNTAX
       Bool XQueryExtension(display,  name,  major_opcode_return,
              first_event_return, first_error_return)

       char **XListExtensions(display, nextensions_return)

       XFreeExtensionList(list)

ARGUMENTS
       display   Specifies the connection to the X server.

       name      Specifies the extension name.

       major_opcode_return
                 Returns the major opcode.

       first_event_return
                 Returns the first event code, if any.

       first_error_return
                 Returns the first error code, if any.

       nextensions_return
                 Returns the number of extensions listed.

       list      Specifies the list of extension names.

DESCRIPTION
       The  XQueryExtension  function  determines  if  the  named
       extension is present.  If the extension  is  not  present,
       XQueryExtension returns False; otherwise, it returns True.
       If the extension is present, XQueryExtension  returns  the
       major  opcode  for  the  extension to major_opcode_return;
       otherwise, it returns zero.   Any  minor  opcode  and  the
       request  formats  are  specific  to the extension.  If the
       extension involves additional event types, XQueryExtension
       returns  the  base  event type code to first_event_return;
       otherwise, it returns zero. The format of  the  events  is
       specific  to  the  extension.   If  the extension involves
       additional error codes, XQueryExtension returns  the  base
       error  code  to  first_error_return; otherwise, it returns
       zero.  The format of additional data in the errors is spe-
       cific  to  the extension.  If the extension name is not in
       the Host Portable Character Encoding the result is  imple-
       mentation-dependent.   Uppercase and lowercase matter; the
       strings ``thing'', ``Thing'', and ``thinG'' are  all  con-
       sidered different names.

       The  XListExtensions function returns a list of all exten-
       sions supported by the server. If the data returned by the
       server  is  in the Latin Portable Character Encoding, then
       the returned strings are in the  Host  Portable  Character
       Encoding.  Otherwise,  the result is implementation-depen-
       dent.

       The XFreeExtensionList function frees the memory allocated
       by XListExtensions.



X Version 11               libX11 1.1.5        XQueryExtension(3)