XQueryExtension(3) X FUNCTIONS 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 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 1.8.10 XQueryExtension(3)