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
41       major_opcode_return;  otherwise, it returns zero.  Any minor opcode and
42       the request formats are specific to the extension.   If  the  extension
43       involves additional event types, XQueryExtension returns the base event
44       type code to first_event_return; otherwise, it returns zero.  The  for‐
45       mat  of  the  events  is  specific  to the extension.  If the extension
46       involves additional error codes, XQueryExtension returns the base error
47       code  to first_error_return; otherwise, it returns zero.  The format of
48       additional data in the errors is specific to  the  extension.   If  the
49       extension  name  is  not  in  the  Host Portable Character Encoding the
50       result is implementation-dependent.  Uppercase  and  lowercase  matter;
51       the  strings “thing”, “Thing”, and “thinG” are all considered different
52       names.
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54       The XListExtensions function returns a list of all extensions supported
55       by the server.  If the data returned by the server is in the Latin Por‐
56       table Character Encoding, then the returned strings  are  in  the  Host
57       Portable  Character Encoding.  Otherwise, the result is implementation-
58       dependent.
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60       The XFreeExtensionList function frees the memory allocated by  XListEx‐
61       tensions.
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65X Version 11                     libX11 1.6.9               XQueryExtension(3)