xvfb-run

Run the specified command in a virtual X server

$ xvfb-run [command]

Try to get a free server number, if the default (99) is not available

$ xvfb-run --auto-servernum [command]

Pass arguments to the Xvfb server

$ xvfb-run --server-args "[-screen 0 1024x768x24]" [command]

xvfb-run [ options ] command

xvfb-run is a wrapper for the Xvfb(1x) command which simplifies the task of running commands (typically an X client, or a script containing a list of clients to be run) within a virtual X server environment.

xvfb-run sets up an X authority file (or uses an existing user-specified one), writes a cookie to it (see xauth(1x)) and then starts the Xvfb X server as a background process. The process ID of Xvfb is stored for later use. The specified command is then run using the X display corresponding to the Xvfb server just started and the X authority file created earlier.

When the command exits, its status is saved, the Xvfb server is killed (using the process ID stored earlier), the X authority cookie removed, and the authority file deleted (if the user did not specify one to use). xvfb-run then exits with the exit status of command.

xvfb-run requires the xauth command to function.

-a, --auto-servernum

Try to get a free server number, starting at 99, or the argument to --server-num.

-e file, --error-file=file

Store output from xauth and Xvfb in file. The default is /dev/null.

-f file, --auth-file=file

Store X authentication data in file. By default, a temporary directory called xvfb-run.PID (where PID is the process ID of xvfb-run itself) is created in the directory specified by the environment variable TMPDIR (or /tmp if that variable is null or unset), and the tempfile(1) command is used to create a file in that temporary directory called Xauthority.

-h, --help

Display a usage message and exit.

-n servernumber, --server-num=servernumber

Use servernumber as the server number (but see the -a, --auto-servernum option above). The default is 99.

-l, --listen-tcp

Enable TCP port listening in the X server. For security reasons (to avoid denial-of-service attacks or exploits), TCP port listening is disabled by default.

-p protocolname, --xauth-protocol=protocolname

Use protocolname as the X authority protocol to use. The default is ‘.’, which xauth interprets as its own default protocol, which is MIT-MAGIC-COOKIE-1.

-s arguments, --server-args=arguments

Pass arguments to the Xvfb server. Be careful to quote any whitespace characters that may occur within arguments to prevent them from regarded as separators for xvfb-run's own arguments. Also, note that specification of ‘-nolisten tcp’ in arguments may override the function of xvfb-run's own -l, --listen-tcp option, and that specification of the server number (e.g., ‘:1’) may be ignored because of the way the X server parses its argument list. Use the xvfb-run option -n servernumber, --server-num=servernumber to achieve the latter function. The default is ‘-screen 0 1280x1024x24’.

-w delay, --wait=delay

Ignored for compatibility with earlier versions.

COLUMNS

indicates the width of the terminal device in character cells. This value is used for formatting diagnostic messages. If not set, the terminal is queried using stty(1) to determine its width. If that fails, a value of ‘80’ is assumed.

TMPDIR

specifies the directory in which to place xvfb-run's temporary directory for storage of the X authority file; only used if the -f or --auth-file options are not specified.

Unless the -f or --auth-file options are specified, a temporary directory and file within it are created (and deleted) to store the X authority cookies used by the Xvfb server and client(s) run under it. See tempfile(1). If -f or --auth-file are used, then the specified X authority file is only written to, not created or deleted (though xauth creates an authority file itself if told to use use that does not already exist).

An error file with a user-specified name is also created if the -e or --error-file options are specified; see above.

xvfb-run uses its exit status as well as output to standard error to communicate diagnostics. The exit status of ‘1’ is not used, and should be interpreted as failure of the specified command.

0

xvfb-run only uses this exit status if the -h, --help option is given. In all other situations, this may be interpreted as success of the specified command.

2

No command to run was specified.

3

The xauth command is not available.

4

The temporary directory that was going to be used already exists; since xvfb-run produces a uniquely named directory, this may indicate an attempt by another process on the system to exploit a temporary file race condition.

5

A problem was encountered while cleaning up the temporary directory.

6

A problem was encountered while using getopt(1) to parse the command-line arguments.

xvfb-run --auto-servernum --server-num=1 xlogo

runs the xlogo(1x) demonstration client inside the Xvfb X server on the first available server number greater than or equal to 1.

xvfb-run --server-args="-screen 0 1024x768x24" ico -faces

runs the ico(1x) demonstration client (and passes it the -faces argument) inside the Xvfb X server, configured with a root window of 1024 by 768 pixels and a color depth of 24 bits.

Note that the demo X clients used in the above examples will not exit on their own, so they will have to be killed before xvfb-run will exit.

See the Debian Bug Tracking System ⟨URL: https://bugs.debian.org/xvfb ⟩. If you wish to report a bug in xvfb-run, please use the reportbug(1) command.

Xvfb(1x), xauth(1x)

xvfb-run was written by Branden Robinson and Jeff Licquia with sponsorship from Progeny Linux Systems.