XSERVER(1) BSD XSERVER(1)
NAME
X - X Window System server
SYNOPSIS
X [:displaynumber] [-option ...] [ttyname]
DESCRIPTION
X is the generic name for the X Window System server. It is frequently a
link or a copy of the appropriate server binary for driving the most
frequently used server on a given machine. On Apollo systems, Xapollo is
the name of the X server.
STARTING THE SERVER
Xapollo is typically started by the user at login via the xinit client or
at workstation boot time using /etc/rc.local.
On non-Apollo systems, the server is usually started from the X Display
Manager program xdm. This utility is run from the system boot files and
takes care of keeping the server running, prompting for usernames and
passwords, and starting up the user sessions. It is easily configured
for sites that wish to provide nice, consistent interfaces for novice
users (loading convenient sets of resources, starting up a window
manager, clock, and nice selection of terminal emulator windows).
Since xdm now handles automatic starting of the server in a portable way,
the -L option to xterm is now considered obsolete. Support for starting
a login window from 4.3bsd-derived /etc/ttys files may not be included in
future releases.
Installations that run more than one window system will still need to use
the xinit utility. However, xinit is to be considered a tool for
building startup scripts and is not intended for use by end users.
NETWORK CONNECTIONS
The server supports connections made using the following reliable byte-
streams:
TCP/IP
The server listens on port htons(6000+n), where n is the display
number.
Unix Domain
The server uses /tmp/.X11-unix/Xn as the filename for the socket,
where n is the display number.
DECnet
The server responds to connections to object X$Xn, where n is the
display number.
OPTIONS
The following command line options are accepted:
-a number
sets pointer acceleration (i.e. the ratio of how much is reported
to how much the user actually moved the pointer).
-bs disables backing store support on all screens. [Not available on
Xapollo.]
-c turns off key-click.
c volume
sets key-click volume (allowable range: 0-8).
-f volume
sets feep (bell) volume (allowable range: 0-7).
-logo turns on the X Window System logo display in the screen-saver.
There is currently no way to change this from a client.
nologo turns off the X Window System logo display in the screen-saver.
There is currently no way to change this from a client.
-p minutes
sets screen-saver pattern cycle time in minutes.
-r turns off auto-repeat.
r turns on auto-repeat.
-s minutes
sets screen-saver timeout time in minutes.
-su disables save under support on all screens. [Not available on
Xapollo.]
-t numbers
sets pointer acceleration threshold in pixels (i.e. after how
many pixels pointer acceleration should take effect).
-to seconds
sets default screensaver timeout in seconds.
v sets video-on screen-saver preference.
-v sets video-off screen-saver preference
-co filename
sets name of RGB color database
-help prints a usage message
-fp fontPath
sets the search path for fonts
-fc cursorFont
sets default cursor font
-fn font
sets the default font
-wm forces the default backing-store of all windows to be WhenMapped;
a cheap trick way of getting backing-store to apply to all
windows. [Not available on Xapollo.] See the manual pages for
Xapollo for more Apollo-specific details.
SECURITY
The server uses an access control list for deciding whether or not to
accept connections from clients on a particular machine. This list
initially consists of the host on which the server is running as well as
any machines listed in the file /etc/Xn.hosts, where n is the display
number of the server. Each line of the file should contain either an
Internet hostname (e.g. expo.lcs.mit.edu) or a DECnet hostname in double
colon format (e.g. hydra::). There should be no leading or trailing
spaces on any lines. For example:
joesworkstation
corporate.company.com
star::
bigcpu::
Users can add or remove hosts from this list and enable or disable access
control using the xhost command from the same machine as the server. For
example:
% xhost +janesworkstation
janesworkstation being added to access control list
% xhost -star::
public:: being removed from access control list
% xhost +
all hosts being allowed (access control disabled)
% xhost -
all hosts being restricted (access control enabled)
% xhost
access control enabled (only the following hosts are allowed)
joesworkstation
janesworkstation
corporate.company.com
bigcpu::
Unlike some window systems, X does not have any notion of window
operation permissions or place any restrictions on what a client can do;
if a program can connect to a display, it has full run of the screen.
The core protocol does have support for providing authentication
information when establishing connections, but is not used in the sample
implementation. Sites that have authentication and authorization systems
(such as Kerberos) might wish to make use of the hooks in the libraries
and the server to provide additional security.
SIGNALS
The server attaches special meaning to the following signals:
SIGHUP This signal causes the server to close all existing connections,
free all resources, and restore all defaults. It is sent by the
display manager whenever the main user's main application
(usually an xterm or window manager) exits to force the server to
clean up and prepare for the next user.
SIGTERM This signal causes the server to exit cleanly.
FONTS
Fonts are usually stored as individual files in directories. The list of
directories in which the server looks when trying to open a font is
controlled by the font path. Although most sites will choose to have the
server start up with the appropriate font path (using the -fp option
mentioned above), it can be overridden using the xset program.
The default font path for the sample server contains three directories:
/usr/lib/X11/fonts/misc
This directory contains several miscellaneous fonts that are
useful on all systems. It contains a very small family of
fixed-width fonts (6x10, 6x12, 6x13, 8x13, 8x13bold, and 9x15)
and the cursor font. It also has font name aliases for the
commonly used fonts fixed and variable.
/usr/lib/X11/fonts/75dpi
This directory contains fonts contributed by Adobe Systems, Inc.
and Digital Equipment Corporation and by Bitstream, Inc. for 75
dots per inch displays. An integrated selection of sizes,