Table of Contents
NetBSD uses the X Window System to provide a graphical interface.
Please note that the X Window System is a rather bare bones framework. It acts as a base for modern desktop environments like MATE, or Xfce, but they are not part of the X Window System. NetBSD ships with the X Window System, but it does not include these desktop environments; they must be added via pkgsrc.
When you start using X you'll find many new terms which you may find confusing at first. The basic elements are:
An X server running on top of the
hardware. The X server provides a standard way to display
graphics (including fonts for text display) and get
On most NetBSD ports, the
Xorg(1) display server is used.
Other X servers included with NetBSD include
which runs an X server inside another X server as a window,
and Xvfb(1), which runs an off-screen X server,
and is typically used to provide a full remote-only desktop with
X clients. These are the programs you
directly interact with. They run on top of the X server. A web
browser like Firefox is an example of an X client. X is
network-transparent, which means that you can run X clients on one
machine, and the X server (i.e., the display, with video hardware)
on another machine.
The X client picks a server to use as a display based on
DISPLAY environment variable,
:0 for the first server, and
:1 for the second.
A window manager running on top of the X server. The window manager is a special X client that is allowed to control the placement of windows. It can also “decorate” windows with standard “widgets” (usually these provide actions like window motion, resizing, iconifying, window killing, etc.). ctwm(1) is NetBSD's default window manager.
A desktop environment such as MATE, or Xfce. These are suites of integrated software designed to give you a well-defined range of software and a more or less common interface to each program. These typically include a window manager, file manager, web browser, email client, multimedia player, text editor, address book, help browser, etc. As you may have guessed, a desktop environment is not needed to use X, but many users will want to install one.
A compositor or
compositing manager runs on the X server and
redirects rendering to an off-screen buffer, typically using the
GPU (Graphics Processing Unit) hardware for final rendering.
It can provide additional eye-candy and often VSync (vertical sync).
Some window managers, typically those included with large desktop
environments, include their own compositing managers.
are external compositing managers.
On NetBSD, X11 lives under the filesystem hierarchy
/usr/X11R7. Therefore, to use X,
/usr/X11R7/bin must be in your shell's
In most cases, you will be able to start using X without any configuration at all, and startx will work just fine.
In rare cases, however, configuration of the X
server is required. This configuration file is located at
/etc/X11/xorg.conf. The structure of the
configuration file is described formally in xorg.conf(5).
To generate an initial configuration file for your X server, run the command
This command should create a configuration file and place it in your home directory. To test the generated configuration file, run, e.g.,
X -config ~/xorg.conf.new
If this succeeds, you should see a crosshatched background and a cursor in the shape of an X. Try moving the cursor around to verify that the mouse is functional. You can then switch to another virtual terminal (Ctrl-Alt-F#) or log in remotely and kill the X process.
If the above test was successful, move the file into place
/etc/X11/xorg.conf and you are ready to go.
Even if you have already configured your keyboard for wscons (see Section 8.1, “wscons”), you need to configure it for X as well, at least if you want to use a non-US layout.
An easy solution is to use setxkbmap(1) .
Here is an example that shows how to use a Hebrew keyboard, with Ctrl-Alt used to switch layouts, and with the position of the Escape and Caps Lock keys swapped as an additional option:
setxkbmap -option grp:alt_shift_toggle us,il \ -option caps:swapescape -option terminate:ctrl_alt_bksp
If you wish to change the repeat rate of your keyboard, you can set it with the xset(1) command, which takes two arguments: delay and rate, respectively. The following example sets the initial delay to 200 milliseconds and the repeat rate to 30 per second:
xset r 200 30
You can also run this command in your
See below (Section 9.6, “Customizing X”) for more
If X does not run at the resolution you think it should, first run xrandr and see if the resolution you want is listed. If your preferred resolution is listed in that command's output, you can change resolutions with, e.g.,
xrandr -s 1680x1050
xrandr can also be used to enable output to hot-plugged monitors.
Managing outputs can be done graphically with the
You can start X with the following command:
If your basic X server configuration is correct, you are left in the X environment with the default window manager (ctwm). If you want a more advanced window manager or desktop environment, many are available in pkgsrc. See Section 9.7, “Other window managers or desktop environments” for information about adding and changing window managers.
One of the first things you will want to do is to change the
programs that run when X is first started. The easiest way to do this
is to copy the default
.xinitrc file to your home
directory and modify it, or create a simple new one from scratch.
cp /etc/X11/xinit/xinitrc ~/.xinitrc
chmod u+w ~/.xinitrc
If you use xdm(1),
~/.xsession is used
in place of
The following example shows how to start the window manager
(ctwm) and open an instance of the
xterm and xterm
programs. The screen background color is set to “bisque4”,
which is defined in
... # start some programs - a basic clcok xclock -geometry 50x50-1-1 & # change the color of the "root window" ("desktop background") xsetroot -solid bisque4 & # spawn a terminal uxterm -geometry 80x34-1+1 -bg OldLace & exec ctwm -W # no '&' here
With this type of setup, to quit X you must exit the window manager, which is usually done by selecting "exit" from its menu.
The above example is very simple, but illustrates the basics
of controlling the clients that are run when X is started. You can
run any number of commands from your
including basic X configuration commands like
xset b off to turn off the bell.
If you don't like ctwm, which is a very
simple window manager, you can install another window manager or
a desktop environment from pkgsrc.
The following example uses the Openbox window manager, but there are
many others available in
Openbox can be installed via binary packages or compiled with pkgsrc. As always, assuming a properly set PKG_PATH, the binary package method is:
pkgin in openbox
To build it with pkgsrc, run:
Openbox is now installed; to start it you must modify your
substitute the line which calls
a line which calls
# start some useful programs xclock -geometry 50x50-1-1 & # start window manager: exec openbox # no '&' here
The startx command will start the X11 session
with Openbox. As configured in the example
file above, choosing “Log Out” from Openbox's
menu will end the X11 session.
Installing a desktop environment is almost as easy. The following example shows how to use the Xfce desktop environment.
pkgin in xfce4
Depending on your requirements, you may wish to enable dbus as a system-wide service. The following example demonstates how. (If you don't enable dbus to run as a system-wide service, startxfce4 will start dbus under your user account during initialization.)
cp /usr/pkg/share/examples/rc.d/dbus /etc/rc.d
echo dbus=YES >> /etc/rc.conf
service dbus start
If you wish to be able to control your system's power state from within the desktop, the account you intend to run X under must also be a member of the “operator” group (see Section 5.6, “Adding users”).
After running the above commands, edit your
.xinitrc as above and change
“openbox” (or “ctwm”) to
“startxfce4”. The next time you run
startx the Xfce desktop environment will be
If you always use X and the first thing you do after you log in is run startx, you can set up a graphical login to do this automatically. It is very easy:
.xsession file in your home
directory. This file is similar to
and can, in fact, be a link to it.
ln -s .xinitrc ~/.xsession
/etc/rc.conf, adding the following
xdm=YES # x11 display manager
Start xdm(1) (or reboot your system, as this will be done automatically from now on):
service xdm start
The configuration files for xdm
are in the
Xservers file specifies the
virtual console that X is started on. It defaults to
“vt05”, which is the console you reach via
“Ctrl+Alt+F5”. If you want to use a different virtual
console, change vt05 as desired. In order to avoid keyboard contention
between getty and xdm, be sure to start xdm on a virtual terminal
where getty is disabled. For example, if in
Xservers you have:
:0 local /usr/X11R7/bin/X :0 vt04
/etc/ttys you should have
ttyE3 "/usr/libexec/getty Pc" wsvt25 off secure
(Please note that vt04 corresponds to ttyE3; in
/etc/X11/xdm/Xservers, numbering starts at 1,
/etc/ttys, numbering starts at 0.)
If you are using xdm to start various
modern desktop environments, such as Xfce or MATE, you will need to
override its default permitted authorization mechanisms, by adding
the following to
If you want to change the look of your xdm login screen, you can
modify the xdm configuration file.
For example, to change the background color you can add the
following line to the
xsetroot -solid SeaGreen
This is intended as a simple example of how to use multiple
X servers. For illustration purposes, we'll simply use
Xnest(1), which creates a new X server
:1 as a window on the existing server
Xnest :1 &
It's then possible to run programs on the second server, or even a different window manager:
DISPLAY=:1 uxterm &
DISPLAY=:1 ctwm &
Using X11 forwarding, programs
can run on a remote machine while displaying on the local
machine. This must typically be enabled in
Log in with ssh(1) and run X programs the normal way:
ssh -X remote.machine.example.com
On a completely headless system (with no monitor),
Xvfb(1) (X virtual framebuffer)
can be used in a similar manner. The fully virtual
screen of the X server can be exported over the network with
Xvfb :1 &
DISPLAY=:1 ctwm &
x11vnc -display :1 -localhost -passwdfile /path/to/password &
Notice we use the
In theory this stops remote connections, however, in practice
we're using a SSH tunnel to forward the VNC port, adding an extra
layer of security. To connect to the headless machine:
ssh -L 5900:hostname:5900 hostname
vncviewer localhost &
An X Window System Tutorial is a video series that attempts to explain basic concepts of the X Window System, including the role of the window manager.