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 specific to the extension.
       If the extension name is not in the Host  Portable  Character  Encoding  the  result  is  implementation-
       dependent.   Uppercase and lowercase matter; the strings “thing”, “Thing”, and “thinG” are all considered
       different names.

       The XListExtensions function returns a list of all extensions 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-dependent.

       The XFreeExtensionList function frees the memory allocated by XListExtensions.

X Version 11                                      libX11 1.8.7                                XQueryExtension(3)