| XEV(1) | General Commands Manual | XEV(1) | 
xev - print contents of X events
xev [-display displayname] [-geometry geom] [-bw
  pixels] [-bs {NotUseful,WhenMapped,Always}] [-id
  windowid] [-root] [-s] [-name string] [-rv] [-version] [-event
  event_mask [-event event_mask ...]]
Xev 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 usage.
  - -display display
- This option specifies the X server to contact.
- -geometry geom
- This option specifies the size and/or location of the window, if a window
      is to be created.
- -bw pixels
- This option specifies the border width for the window.
- -bs {NotUseful,WhenMapped,Always}
- 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.
- -id windowid
- This option specifies that the window with the given id should be
      monitored, instead of creating a new window.
- -root
- This option specifies that the root window should be monitored, instead of
      creating a new window.
- -s
- 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.
- -name string
- This option specifies the name to assign to the created window.
- -rv
- This option specifies that the window should be in reverse video.
- -event event_mask
- 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
- -version
- This option prints the program version and exits.
X(7), xwininfo(1), xdpyinfo(1), Xlib Programmers Manual, X Protocol
  Specification
Jim Fulton, MIT X Consortium