Xvfb(1) - NetBSD Manual Pages

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XVFB(1)							  XVFB(1)



NAME

       Xvfb - virtual framebuffer X server for X Version 11


SYNOPSIS

       Xvfb [ option ] ...


DESCRIPTION

       Xvfb  is an X server that can run on machines with no dis
       play hardware and no physical input devices.  It	 emulates
       a dumb framebuffer using virtual memory.

       The  primary  use of this server was intended to be server
       testing.	 The mfb or cfb code for any depth can	be  exer
       cised  with this server without the need for real hardware
       that supports the desired depths.   The	X  community  has
       found  many  other  novel uses for Xvfb, including testing
       clients against unusual depths and screen  configurations,
       doing batch processing with Xvfb as a background rendering
       engine, load testing, as an aid to porting the X server to
       a  new  platform,  and providing an unobtrusive way to run
       applications that don't really need an X server but insist
       on having one anyway.


BUILDING

       To  build  Xvfb,	 put  the  following in your host.def and
       remake.

       #define BuildServer YES
       #define XVirtualFramebufferServer YES



OPTIONS

       In addition to the normal server options described in  the
       Xserver(1) manual page, Xvfb accepts the following command
       line switches:

       -screen screennum WxHxD
	   This option creates	screen	screennum  and	sets  its
	   width,  height, and depth to W, H, and D respectively.
	   By default, only screen 0 exists and	 has  the  dimen
	   sions 1280x1024x8.

       -pixdepths list-of-depths
	   This option specifies a list of pixmap depths that the
	   server  should  support  in	addition  to  the  depths
	   implied by the supported screens.  list-of-depths is a
	   space-separated list of integers that can have  values
	   from 1 to 32.

       -fbdir framebuffer-directory
	   This	 option specifies the directory in which the mem
	   ory mapped files  containing	 the  framebuffer  memory
	   should  be  created.	  See  FILES.	This  option only
	   exists on machines that have the mmap and msync system



X Version 11		   Release 6.6				1





XVFB(1)							  XVFB(1)


	   calls.

       -shmem
	   This	 option	 specifies that the framebuffer should be
	   put in shared memory.  The shared memory ID	for  each
	   screen will be printed by the server.  The shared mem
	   ory is in xwd format.   This	 option	 only  exists  on
	   machines  that  support  the	 System	 V  shared memory
	   interface.

       If neither -shmem nor -fbdir is specified, the framebuffer
       memory will be allocated with malloc().

       -linebias n
	   This	 option	 specifies how to adjust the pixelization
	   of thin lines.  The value n is a bitmask of octants in
	   which to prefer an axial step when the Bresenham error
	   term	   is	 exactly    zero.     See    the     file
	   Xserver/mi/miline.h for more information.  This option
	   is probably only useful to server developers to exper
	   iment  with	the  range  of line pixelization possible
	   with the cfb and mfb code.

       -blackpixel pixel-value, -whitepixel pixel-value
	   These options specify the black and white pixel values
	   the server should use.


FILES

       The  following  files  are created if the -fbdir option is
       given.

       framebuffer-directory/Xvfb_screen<n>
	   Memory mapped file containing screen	 n's  framebuffer
	   memory,  one file per screen.  The file is in xwd for
	   mat.	 Thus, taking a full-screen snapshot can be  done
	   with	 a  file copy command, and the resulting snapshot
	   will even contain the cursor image.


EXAMPLES

       Xvfb :1 -screen 0 1600x1200x32
	       The server will listen for connections  as  server
	       number 1, and screen 0 will be depth 32 1600x1200.

       Xvfb :1 -screen 1 1600x1200x16
	       The server will listen for connections  as  server
	       number  1, will have the default screen configura
	       tion (one screen, 1280x1024x8), and screen 1  will
	       be depth 16 1600x1200.

       Xvfb -pixdepths 3 27 -fbdir /usr/tmp
	       The  server  will listen for connections as server
	       number 0, will have the default screen  configura
	       tion  (one screen, 1280x1024x8), will also support
	       pixmap depths of 3 and 27,  and	will  use  memory



X Version 11		   Release 6.6				2





XVFB(1)							  XVFB(1)


	       mapped files in /usr/tmp for the framebuffer.

       xwud -in /usr/tmp/Xvfb_screen0
	       Displays	 screen	 0  of	the server started by the
	       preceding example.


SEE ALSO

       X(7), Xserver(1), xwd(1), xwud(1), XWDFile.h


AUTHORS

       David P. Wiggins, The Open Group, Inc.














































X Version 11		   Release 6.6				3