This is the command Xvfb that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
Xvfb - virtual framebuffer X server for X Version 11
Xvfb [ option ] ...
Xvfb is an X server that can run on machines with no display 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 fb code for any
depth can be exercised 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.
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 dimensions
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.
This option specifies the directory in which the memory mapped files containing the
framebuffer memory should be created. See FILES. This option only exists on machines
that have the mmap and msync system calls.
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 memory is in xwd
format. This option only exists on machines that support the System V shared memory
If neither -shmem nor -fbdir is specified, the framebuffer memory will be allocated with
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 experiment with the range of line
pixelization possible with the fb code.
-blackpixel pixel-value, -whitepixel pixel-value
These options specify the black and white pixel values the server should use.
Use Xvfb online using onworks.net services