Table of ContentsXvfb - 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 is intended to be server testing. The mfb or cfb code for any depth can be exercised with this server without the need for real hardware that supports the desired depths.
A secondary use is testing clients against unusual depths and screen configurations.
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 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 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.
- -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 memory 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().
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 format.
- 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 configuration (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 configuration (one screen, 1280x1024x8), will also support pixmap depths of 3 and 27, and will use memory 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.
X(1), Xserver(1), xwd(1), xwud(1), XWDFile.h
David P. Wiggins, X Consortium, Inc.
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