XQueryExtension, XListExtensions, XFreeExtensionList - list available extensions
Bool XQueryExtension(display, name,
major_opcode_return, first_event_return,
first_error_return)
char **XListExtensions(display,
nextensions_return)
XFreeExtensionList(list)
- 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.
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.