Xephyr(1)                   General Commands Manual                  Xephyr(1)

NAME
       Xephyr - X server outputting to a window on a pre-existing X display

SYNOPSIS
       Xephyr [:display] [option ...]

DESCRIPTION
       Xephyr is a kdrive server that outputs to a window on a pre-existing
       "host" X display.  Think Xnest but with support for modern extensions
       like composite, damage and randr.

       Unlike Xnest which is an X proxy, i.e.  limited to the capabilities of
       the host X server, Xephyr is a real X server which uses the host X
       server window as "framebuffer" via fast SHM XImages.

       It also has support for "visually" debugging what the server is
       painting.

OPTIONS
       The server accepts all the standard options of Xserver(1) and the
       following additional options:

       -screen widthxheight
               sets the screen size.

       -parent id
               uses existing window id .  If a -screen argument follows a
               -parent argument, this screen is embedded into the given
               window.

       -host-cursor
               set 'cursor acceleration': The host's cursor is reused. This is
               only really there to aid debugging by avoiding server paints
               for the cursor. Performance improvement is negligible.

       -resizeable
               Allow the Xephyr window to be resized, even if not embedded
               into a parent window. By default, the Xephyr window has a fixed
               size.

       -no-host-grab
               Disable grabbing the keyboard and mouse.

SIGNALS
       Send a SIGUSR1 to the server (e.g. pkill -USR1 Xephyr) to toggle the
       debugging mode.  In this mode red rectangles are painted to screen
       areas getting painted before painting the actual content.  The delay
       between this can be altered by setting a XEPHYR_PAUSE env var to a
       value in micro seconds.

CAVEATS
       • Rotated displays are currently updated via full blits. This is slower
         than a normal orientated display. Debug mode will therefore not be of
         much use rotated.

       • The '-host-cursor' cursor is static in its appearance.

       • The build gets a warning about 'nanosleep'. I think the various '-D'
         build flags are causing this. I haven't figured as yet how to work
         round it. It doesn't appear to break anything however.

       • Keyboard handling is basic but works.

       • Mouse button 5 probably won't work.

SEE ALSO
       X(7), Xserver(1)

AUTHOR
       Matthew Allum <mallum@o-hand.com> 2004

X Version 11                  xorg-server 1.20.14                    Xephyr(1)