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 addi-
       tional data in the errors is specific to the extension.  If the  exten-
       sion  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  Por-
       table  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 XListEx-
       tensions.

X Version 11                     libX11 1.1.1               XQueryExtension(3)