1XQueryExtension(3)                X FUNCTIONS               XQueryExtension(3)
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NAME

6       XQueryExtension,  XListExtensions,  XFreeExtensionList - list available
7       extensions
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SYNTAX

10       Bool      XQueryExtension(display,      name,      major_opcode_return,
11              first_event_return, first_error_return)
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13       char **XListExtensions(display, nextensions_return)
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15       XFreeExtensionList(list)
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ARGUMENTS

18       display   Specifies the connection to the X server.
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20       name      Specifies the extension name.
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22       major_opcode_return
23                 Returns the major opcode.
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25       first_event_return
26                 Returns the first event code, if any.
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28       first_error_return
29                 Returns the first error code, if any.
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31       nextensions_return
32                 Returns the number of extensions listed.
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34       list      Specifies the list of extension names.
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DESCRIPTION

37       The  XQueryExtension  function  determines  if  the  named extension is
38       present.  If the extension  is  not  present,  XQueryExtension  returns
39       False;  otherwise,  it  returns  True.   If  the  extension is present,
40       XQueryExtension returns the major opcode for the extension to major_op‐
41       code_return;  otherwise, it returns zero.  Any minor opcode and the re‐
42       quest formats are specific to the extension.  If the extension involves
43       additional  event  types,  XQueryExtension  returns the base event type
44       code to first_event_return; otherwise, it returns zero.  The format  of
45       the events is specific to the extension.  If the extension involves ad‐
46       ditional error codes, XQueryExtension returns the base  error  code  to
47       first_error_return;  otherwise,  it  returns zero.  The format of addi‐
48       tional data in the errors is specific to the extension.  If the  exten‐
49       sion  name is not in the Host Portable Character Encoding the result is
50       implementation-dependent.  Uppercase and lowercase matter; the  strings
51       “thing”, “Thing”, and “thinG” are all considered different names.
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53       The XListExtensions function returns a list of all extensions supported
54       by the server.  If the data returned by the server is in the Latin Por‐
55       table  Character  Encoding,  then  the returned strings are in the Host
56       Portable Character Encoding.  Otherwise, the result is  implementation-
57       dependent.
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59       The  XFreeExtensionList function frees the memory allocated by XListEx‐
60       tensions.
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64X Version 11                     libX11 1.8.1               XQueryExtension(3)