1XVFB(1) General Commands Manual XVFB(1)
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6 Xvfb - virtual framebuffer X server for X Version 11
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9 Xvfb [ option ] ...
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12 Xvfb is an X server that can run on machines with no display hardware
13 and no physical input devices. It emulates a dumb framebuffer using
14 virtual memory.
15 The primary use of this server was intended to be server testing. The
17 fb code for any depth can be exercised with this server without the
18 need for real hardware that supports the desired depths. The X commu‐
19 nity has found many other novel uses for Xvfb, including testing
20 clients against unusual depths and screen configurations, doing batch
21 processing with Xvfb as a background rendering engine, load testing, as
22 an aid to porting the X server to a new platform, and providing an
23 unobtrusive way to run applications that don't really need an X server
24 but insist on having one anyway.
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27 To build Xvfb, put the following in your host.def and remake.
28 #define BuildServer YES /∗ if you aren't already building other servers
30 */
31 #define XVirtualFramebufferServer YES
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35 In addition to the normal server options described in the Xserver(1)
36 manual page, Xvfb accepts the following command line switches:
37 -screen screennum WxHxD
39 This option creates screen screennum and sets its width, height,
40 and depth to W, H, and D respectively. By default, only screen 0
41 exists and has the dimensions 1280x1024x12.
42 -pixdepths list-of-depths
44 This option specifies a list of pixmap depths that the server
45 should support in addition to the depths implied by the supported
46 screens. list-of-depths is a space-separated list of integers that
47 can have values from 1 to 32.
48 -fbdir framebuffer-directory
50 This option specifies the directory in which the memory mapped
51 files containing the framebuffer memory should be created. See
52 FILES. This option only exists on machines that have the mmap and
53 msync system calls.
54 -shmem
56 This option specifies that the framebuffer should be put in shared
57 memory. The shared memory ID for each screen will be printed by
58 the server. The shared memory is in xwd format. This option only
59 exists on machines that support the System V shared memory inter‐
60 face.
61 If neither -shmem nor -fbdir is specified, the framebuffer memory will
63 be allocated with malloc().
64 -linebias n
66 This option specifies how to adjust the pixelization of thin lines.
67 The value n is a bitmask of octants in which to prefer an axial
68 step when the Bresenham error term is exactly zero. See the file
69 Xserver/mi/miline.h for more information. This option is probably
70 only useful to server developers to experiment with the range of
71 line pixelization possible with the fb code.
72 -blackpixel pixel-value, -whitepixel pixel-value
74 These options specify the black and white pixel values the server
75 should use.
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78 The following files are created if the -fbdir option is given.
79 framebuffer-directory/Xvfb_screen<n>
81 Memory mapped file containing screen n's framebuffer memory, one
82 file per screen. The file is in xwd format. Thus, taking a full-
83 screen snapshot can be done with a file copy command, and the
84 resulting snapshot will even contain the cursor image.
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87 Xvfb :1 -screen 0 1600x1200x32
88 The server will listen for connections as server number 1, and
89 screen 0 will be depth 32 1600x1200.
90 Xvfb :1 -screen 1 1600x1200x16
92 The server will listen for connections as server number 1, will
93 have the default screen configuration (one screen,
94 1280x1024x12), and screen 1 will be depth 16 1600x1200.
95 Xvfb -pixdepths 3 27 -fbdir /usr/tmp
97 The server will listen for connections as server number 0, will
98 have the default screen configuration (one screen,
99 1280x1024x12), will also support pixmap depths of 3 and 27, and
100 will use memory mapped files in /usr/tmp for the framebuffer.
101 xwud -in /usr/tmp/Xvfb_screen0
103 Displays screen 0 of the server started by the preceding exam‐
104 ple.
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107 X(7), Xserver(1), xwd(1), xwud(1), XWDFile.h
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110 David P. Wiggins, The Open Group, Inc.
111X Version 11 xorg-server 1.3.0.0 XVFB(1)