xev - print
contents of X events
[−display displayname] [−geometry
geom] [−bw pixels] [−bs
windowid] [−root] [−s] [−name
string] [−rv] [−version] [−event
event_mask [−event event_mask ...]]
creates a window and then asks the X server to send it
events whenever anything happens to the window (such
as it being moved, resized, typed in, clicked in, etc.). You
can also attach it to an existing window. It is useful for
seeing what causes events to occur and to display the
information that they contain; it is essentially a debugging
and development tool, and should not be needed in normal
This option specifies the X
server to contact.
This option specifies the size
and/or location of the window, if a window is to be
This option specifies the
border width for the window.
This option specifies what kind
of backing store to give the window. The default is
NotUseful. Backing store refers to the the pixels saved
off-screen when the X server maintains the contents of a
window; NotUseful means that the xev process will redraw its
contents itself, as necessary.
This option specifies that the
window with the given id should be monitored, instead of
creating a new window.
This option specifies that the root window should be
monitored, instead of creating a new window.
This option specifies that save-unders should be enabled
on the window. Save unders are similar to backing store, but
they refer rather to the saving of pixels off-screen when
the current window obscures other windows. Save unders are
only advisory, and are normally set for popup dialogs and
other transient windows.
This option specifies the name
to assign to the created window.
This option specifies that the window should be in
Select which events to display.
The −event option can be specified multiple
times to select multiple types of events. When not
specified, all events are selected. Available event masks:
keyboard mouse expose visibility structure substructure
focus property colormap owner_grab_button randr button
This option prints the program
version and exits.
xwininfo(1), xdpyinfo(1), Xlib Programmers Manual, X
See X(7) for a full statement of rights and
Jim Fulton, MIT