# The &kdm; Handbook

## Introduction

&kdm; provides a graphical interface that allows you to log in to a system. It prompts for login (username) and password, authenticates the user and starts a session. &kdm; is superior to &xdm;, the X Display Manager, in a number of ways.

## Quick Start Guide

This is a quick start guide for users who fit the following pattern:

- X is configured and works with the command `startx` from the commandline.

- Each user will generally only use a single window manager or desktop environment, and does not change this choice very often, or is comfortable editing a single text file in order to change their choice.

This scenario will be sufficient for many environments where a single user or several users normally boot the computer and log into their preferred environment.

## Setting up a Default Session

1. Create or open the file `~/.xinitrc`

   If you already have a working `~/.xinitrc`, go to the next step

2. If one does not already exist, add a line to the `~/.xinitrc` to start your preferred window manager or desktop environment.

   For &kde; you should enter:

       startkde

   For other window managers or desktop environments, you should look in their documentation for the correct command.

3. Make a link as follows:

       ln -s ~/.xinitrc ~/.xsession

At this point, typing ``startx`` on the commandline should start X, with a &kde; session. The next task is to try &kdm;.

As `root`, type ``kdm`` at the prompt.

You should see a login window, which is described more fully inlogin.

Typing your normal username and password in the fields provided, and leaving `default` selected as the session type should now open a &kde; session for your user.

If you have other users to configure, you should repeat the procedure above for each of them.

This is a quick guide to getting up and running only. You probably will want to customise &kdm; further, for example, to hide the names of the system accounts, to allow further sessions, and much more. Please read through the rest of this manual to find out how to do these things.

## The Login Window

The user interface to &kdm; consists of two dialogue boxes. The main dialogue box has these controls:

- A Username: field for you to enter your username.

- A Password: field for you to enter your password.

- (Optionally) a graphical image of each user (for example, a digitised photograph). Clicking on an image is equivalent to typing the associated username into the Username: field. (This feature is an imitation of the login box on IRIX).

- A Menu drop-down box that allows &kdm; to be used to start sessions with various different window managers or desktop environments installed on the system.

- (Optionally) a region to the right of the Username:, Password: and Session Type: fields which can be used to display either a static image or an analogue clock.

- A Login button that validates the username/password combination and attempts to start a session of the selected type.

- A Clear button that clears the text from the Login and Pass fields.

- (Optionally) A Shutdown button that displays the Shutdown dialogue box.

- A Menu button that opens an action menu with the following items:

  - (On local displays) a Restart X Server item that terminates the currently running &X-Server;, starts a new one and displays the login dialogue again. You can use this if the display content seems to be broken somehow.

  - (On remote displays) A Close Connection item that closes the connection to the XDMCP server you are currently connected to. If you got to this server through a host chooser, this will bring you back to the chooser, otherwise it will only reset the &X-Server; and bring up the login dialogue again.

  - (Optionally on local displays) A Console Mode item that terminates the currently running &X-Server; and leaves you alone with a console login. &kdm; will resume the graphical login if nobody is logged in at the console for some time. To make this work, you need to use the local@<console> syntax in the `Xservers` file (see comments in that file).

- (Optionally) A Shutdown... button that displays the shutdown dialogue box.

The Shutdown dialogue box presents a set of radio buttons that allow one of these options to be selected:

Shutdown

- Shut the system down in a controlled manner, ready for power-down.

Restart

- Shut the system down and reboot. For systems that use Lilo, an optional drop-down box allows you to select a particular operating-system kernel to be used for the reboot.

Restart X Server

- Stop and then restart the X-server. Typically, you might need to use this option if you have changed your X11 configuration in some way.

Console Mode

- Stop the &X-Server; and return the system to console mode. This is achieved by bringing the system down to run-level 3. Typically, the system manager might need to use this option before upgrading or re-configuring X11 software.

Pressing the OK button initiates the selected action; pressing the Cancel button returns to the main &kdm; dialogue box.

## Configuring &kdm;

This chapter assumes that &kdm; is already up and running on your system, and that you simply want to change its behaviour in some way.

When &kdm; starts up, it reads its configuration from the folder `$KDEDIR/share/config/kdm/` (this may be `/etc/kde3/kdm/` or something else on your system).

The main configuration file is &kdmrc;; all other files are referenced from there and could be stored under any name anywhere on the system - but usually that would not make much sense for obvious reasons (one particular exception is referencing configuration files of an already installed &xdm; - however when a new &kdm; is installed, it will import settings from those files if it finds an already installed &xdm;).

Since &kdm; must run before any user is logged in, it is not associated with any particular user. Therefore, it is not possible to have user-specific configuration files; all users share the common &kdmrc;. It follows from this that the configuration of &kdm; can only be altered by those users that have write access to `$`KDEDIR`/share/config/kdm/kdmrc` (normally restricted to system administrators logged in as `root`).

You can view the &kdmrc; file currently in use on your system, and you can configure &kdm; by editing this file. Alternatively, you can use the graphical configuration tool provided by the &kcontrolcenter; (under System Administration Login Manager), which is described in the &kcontrol; help files.

The remainder of this chapter describes configuration of &kdm; via the &kcontrol; module, and the next chapter describes the options available in &kdmrc; itself. If you only need to configure for local users, the &kcontrol; module should be sufficient for your needs. If you need to configure remote logins, or have multiple &kdm; sessions running, you will need to read on.

### The Login Manager &kcontrol; Module

Using this module, you can configure the &kde; graphical login manager, &kdm;. You can change how the login screen looks, who has access using the login manager and who can shutdown the computer.

All settings will be written to the configuration file &kdmrc;, which in it's original state has many comments to help you configure &kdm;. Using this &kcontrol; module will strip these comments from the file. All available options in &kdmrc; are covered in kdm-files.

The options listed in this chapter are cross referenced with their equivalents in &kdmrc;. All options available in the &kcontrol; module are also available directly in &kdmrc; but the reverse is not true.

In order to organise all of these options, this module is divided into several sections: Appearance, Font, Background, Shutdown, Users and Convenience.

You can switch between the sections using the tabs at the top of the window.

If you are not currently logged in as a superuser, you will need to click the Administrator Mode Button. You will then be asked for a superuser password. Entering a correct password will allow you to modify the settings of this module.

#### Appearance

From this page you can change the visual appearance of &kdm;, &kde;'s graphical login manager.

The Greeting: is the title of the login screen. Setting this is especially useful if you have many servers users may log in to. You may use various placeholders, which are described along with the corresponding key `GreetString` in &kdmrc;.

You can then choose to show either the current system time, a logo or nothing special in the login box. Make your choice in the radio buttons labelled Logo area:. This corresponds to `LogoArea` in &kdmrc;

If you chose Show logo you can now choose a logo:

- Drop an image file on the image button.

- Click on the image button and select a new image from the image chooser dialogue.

If you do not specify a logo the default `$`KDEDIR`/share/apps/kdm/pics/kdelogo.xpm` will be displayed.

Normally the login box is centred on the screen. Use the Position: options if you want it to appear elsewhere on the screen. You can specify the relative position (percentage of the screen size) for the centre of the login window, relative to the top left of the display, in the fields labelled X: and Y: respectively. These correspond to the key `GreeterPos` in &kdmrc;.

While &kde;'s style depends on the settings of the user logged in, the style used by &kdm; can be configured using the GUI Style: and Colour Scheme: options. These correspond to the keys `GUIStyle` and `ColorScheme` in &kdmrc; respectively.

Below that, you have a dropdown box to choose the language for your login box, corresponding to setting `Language` in &kdmrc;.

#### Font

From this section of the module you can change the fonts used in the login window. Only fonts available to all users are available here, not fonts you have installed on a per user basis.

You can select three different font styles from the drop down box (General:, Failures:, Greeting). When you click on the Choose... button a dialogue appears from which you can select the new characteristics for the font style.

- The General: font is used in all other places in the login window.

- The Failures: font is used when a login fails.

- The Greeting: font is the font used for the title (Greeting String).

You can also check the box labelled Use anti-aliasing for fonts if you want smoothed fonts in the login dialogue.

An example of each font can be seen in the Example Box.

#### Background

Here you can change the desktop background which will be displayed before a user logs in. You can have a single colour or an image as a background. If you have an image as the background and select centre, the selected background colour will be used around the image if it is not large enough to cover the entire desktop.

The background colours and effects are controlled by the options on the tab labelled Background and you select a background image and its placement from the options on the tab labelled Wallpaper.

To change the default background colour(s) simply click either of the colour buttons and select a new colour.

The dropdown box above the colour buttons provides you with several different blend effects. Choose one from the list, and it will be previewed on the small monitor at the top of the window. Your choices are:

Flat

- By choosing this mode, you select one colour (using the colour button labelled Colour 1), and the entire background is covered with this one colour.

Pattern

- By choosing this mode, you select two colours (using both colour buttons).

  You then select a pattern by clicking Setup. This opens a new dialogue window, which gives you the opportunity to select a pattern. Simply click once on the pattern of your choice, then click on OK, and &kde; will render the pattern you selected using the two colours you selected. For more on patterns, see the section Background: Adding, Removing and Modifying Patterns.

Background Program

- By selecting this option, you can have &kde; use an external program to determine the background. This can be any program of your choosing. For more information on this option, see the section entitled Background: Using an external program.

Horizontal Gradient

- By choosing this mode, you select two colours (using both colour buttons). &kde; will then start with the colour selected by Colour 1 on the left edge of the screen, and slowly transform into the colour selected by Colour 2 by the time it gets to the right edge of the screen.

Vertical Gradient

- By choosing this mode, you select two colours (using both colour buttons). &kde; will then start with the colour selected by Colour 1 on the top edge of the screen, and slowly transform into the colour selected by Colour 2 as it moves to the bottom of the screen.

Pyramid Gradient

- By choosing this mode, you select two colours (using both colour buttons). &kde; will then start with the colour selected by Colour 1 in each corner of the screen, and slowly transform into the colour selected by Colour 2 as it moves to the centre of the screen.

Pipecross Gradient

- By choosing this mode, you select two colours (using both colour buttons). &kde; will then start with the colour selected by Colour 1 in each corner of the screen, and slowly transform into the colour selected by Colour 2 as it moves to the centre of the screen. The shape of this gradient is different then the pyramid gradient.

Elliptic Gradient

- By choosing this mode, you select two colours (using both colour buttons). &kde; will then start with the colour selected by Colour 2 in the centre of the screen, and slowly transform into the colour selected by Colour 1 as it moves to the edges, in an elliptical pattern.

The setup button is only needed for if you select Background program or Patterns. In these instances, another window will appear to configure the specifics.

Wallpaper

To select a new background image first, click on the Wallpapers tab, then you can either select an image from the drop-down list labelled Wallpaper or select Browse... and select an image file from a file selector.

The image can be displayed in six different ways:

No wallpaper

- No image is displayed. Just the background colours.

Centred

- The image will be centred on the screen. The background colours will be present anywhere the image does not cover.

Tiled

- The image will be duplicated until it fills the entire desktop. The first image will be placed in the upper left corner of the screen, and duplicated downward and to the right.

Centre Tiled

- The image will be duplicated until it fills the entire desktop. The first image will be placed in the centre of the screen, and duplicated upwards, downwards to the right, and to the left.

Centred Maxpect

- The image will be placed in the centre of the screen. It will be scaled to fit the desktop, but it will not change the aspect ratio of the original image. This will provide you with an image that is not distorted.

Scaled

- The image will be scaled to fit the desktop. It will be stretched to fit all four corners.

#### Shutdown

Allow Shutdown

Use these dropdown box to choose who is allowed to shut down:

- Nobody: No one can shutdown the computer using &kdm;. You must be logged in, and execute a command.

- Everybody: Everyone can shutdown the computer using &kdm;.

- Only Root: &kdm; requires that the `root` password be entered before shutting down the computer.

You can independently configure who is allowed to issue a shutdown command for the Local: and Remote: users.

Commands

Use these text fields to define the exact shutdown command.

The Halt: command defaults to `/sbin/halt`. The restart command defaults to `/sbin/reboot`.

When Show boot options is enabled, &kdm; will on reboot offer you options for the lilo boot manager. For this feature to work, you will need to supply the correct paths to your `lilo` command and to lilo's map file.

##### Session types

Define which session types should be accessible from the login window.

For more information on this subject, look at `/etc/X11/xdm/Xsession` to find your xdm setup files. Also review the xdm man pages, especially under the SESSION PROGRAM section.

To add a session, type its name in the blank entitled New types, and click Add new.

To remove a session, select the session from the list and click Remove.

#### Users

From here you can change the way users are represented in the login window.

You may disable the user list in &kdm; entirely in the Show Users section. You can choose from:

None

- Do not show any users. This is the most secure setting, since an attacker would then have to guess a valid login name as well as a password. It's also the preferred option if you have more than a handful of users to list, or the list itself would become unwieldy.

Selected only

- Only show users you have specifically enabled.

Not hidden

- Allows you to select a list of users that should not be shown, and all other users will be listed.

Independently of the users you specify by name, you can use the System UIDs to specify a range of valid UIDs that are shown in the list. By default user id's under 1000, which are often system or daemon users, and user id's over 65000, are not shown.

You can also enable the Sort users checkbox, to have the user list sorted alphabetically. If this is disabled, users will appear in the order they are listed in the password file.

If you choose to show users, then the login window will show images (which you select), of a list of users. When someone is ready to login, they may select their user name/image, enter their password, and they are granted access.

If you permit a user image, then you can configure the source for those images.

The available options for the User Image Source are:

You can configure the admin picture here, for each user on the system. Depending on the order selected above, users may be able to override your selection.

If you choose not to show users, then the login window will be more traditional. Users will need to type their username and password to gain entrance. This is the preferred way if you have many users on this terminal.

##### To show (and sort) or not to show users

Along the right edge of the window are two check boxes:

If Show users is selected you have chosen to show images of users, instead of making them type their login name.

If Sort users is selected, then the list of users will be sorted alphabetically in the login window. If unchecked, users will be listed in the same order as they are on this page. If Show users is not checked, this has no effect.

##### How to determine which users to show and which users to hide

Below the user image box, and above the Show users check box, is a set of two radio buttions:

- Show only selected users: If this option is selected, only the users contained in the list labelled Selected Users, will be displayed in the login window. If Show users is not checked, this has no effect.

- Show all users but no-show users: If this option is selected, all users will be listed, except those users contained in the list entitled No show users. If Show users is not checked, this has no effect.

##### Select users

This page contains three listboxes. The large listbox on the left shows all the users on the system which might be a genuine user.

The top rightmost listbox shows the selected users and the bottom rightmost listbox shows the users we do not want displayed in the login window.

To move a user from one listbox to another you click on the username in the listbox and click >> to move the user from the leftmost box the the rightmost box or << to move the user from the rightmost box to the leftmost box.

##### Images

This section of the manual only applies if Show users is selected. If it is not, this image box has no effect.

Every user on the system can be represented by an image. The image for each user is kept in a file called `$`KDEDIR`/share/apps/kdm/pics/users/$`USER`.xpm`. If there is no such file for a particular user, the file `$`KDEDIR`/share/apps/kdm/pics/users/default.xpm` will be used instead.

To assign a new image to a user just select the user in one of the listboxes and either drop an imagefile on the image button to the right or click on the image button and select a new image from the image selector.

If no user is currently selected you will be asked if you want to change the default image.

The replacement is performed by a &konqueror; process so if the imagefile already exists you will be prompted by &konqueror; if you want to replace it. If you confirm the image will be replaced - you will NOT have to press the Apply button.

#### Convenience

In the convenience tab you can configure some options that make life easier for lazy people, like automatic login or disabling passwords.

Please think more than twice before using these options. Every option in the Convenience tab is well-suited to seriously compromise your system security. Practically, these options are only to be used in a completely non-critical environment, ⪚ a private computer at home.

##### Automatic Login

Automatic login will give anyone access to a certain account on your system without doing any authentication. You can enable it using the option Enable auto-login.

You can choose the account to be used for automatic login from the list labelled User:.

##### Password-Less Login

Using this feature, you can allow certain users to login without having to provide their password. Enable this feature using the Enable password-less logins option.

Below this option you'll see a list of users on the system. Enable password-less login for specific users by checking the checkbox next to the login names. By default, this feature is disabled for all users.

Again, this option should only be used in a safe environment. If you enable it on a rather public system you should take care that only users with heavy access restrictions are granted password-less login, ⪚ `guest`.

The Automatically login after X server crash option allows you to skip the authentication procedure when your X server accidentally crashed.

You can also choose which user is preselected when &kdm; starts. The default is None, but you can choose Previous to have &kdm; default to the last successfully logged in user, or you can Specify a particular user to always be selected from the list. You can also have &kdm; set the focus to the password field, so that when you reach the &kdm; login screen, you can type the password immediately.

&kdmrc-ref;

## Configuring your system to use &kdm;

This chapter assumes that your system is already configured to run the X Window System, and that you only need to reconfigure it to allow graphical login.

### Setting up &kdm;

The fundamental thing that controls whether your computer boots to a terminal prompt (console mode) or a graphical login prompt is the default runlevel. The runlevel is set by the program /sbin/init under the control of the configuration file `/etc/inittab`. The default runlevels used by different &UNIX; systems (and different &Linux; distributions) vary, but if you look at `/etc/inittab` the start of it should be something like this:

    # Default runlevel. The runlevels used by RHS are:
    # 0 - halt (Do NOT set initdefault to this)
    # 1 - Single user mode
    # 2 - Multiuser, without NFS
    # 3 - Full multiuser mode
    # 4 - unused
    # 5 - X11
    # 6 - reboot (Do NOT set initdefault to this)

    id:3:initdefault:

All but the last line of this extract are comments. The comments show that runlevel 5 is used for X11 and that runlevel 3 is used for multi-user mode without X11 (console mode). The final line specifies that the default runlevel of the system is 3 (console mode). If your system currently uses graphical login (for example, using &xdm;) its default runlevel will match the runlevel specified for X11.

The runlevel with graphical login (&xdm;) for some common &Linux; distributions are:

- 5 for &RedHat; 3.x and later, and for &Mandrake;

- 4 for Slackware

- 3 for &SuSE;. 4.x and 5.x

The first step in configuring your system is to ensure that you can start &kdm; from the command line. Once this is working, you can change your system configuration so that &kdm; starts automatically each time you reboot your system.

To test &kdm;, you must first bring your system to a runlevel that does not run &xdm;. To do so, issue a command like this:

    /sbin/init 3

Instead of the number `3` you should specify the appropriate runlevel for console mode on your system.

If your system uses Pluggable Authentication Modules (PAM), which is normal with recent &Linux; and Solaris systems, you should check that your PAM configuration permits login through the service named `kde`. If you previously used &xdm; successfully, you should not need to make any changes to your PAM configuration in order to use &kdm;. `/etc/pam.conf` or `/etc/pam.d/kde`. Information on configuring PAM is beyond the scope of this handbook, but PAM comes with comprehensive documentation (try looking in `/usr/share/doc/*pam*/html/`).

Now it's time for you to test &kdm; by issuing the following command:

    kdm -nodaemon

If you get a &kdm; login dialogue and you are able to log in, things are going well. The main thing that can go wrong here is that the run-time linker might not find the shared &Qt; or &kde; libraries. If you have a binary distribution of the &kde; libraries, make sure &kdm; is installed where the libraries believe &kde; is installed and try setting some environment variables to point to your &kde; and &Qt; libraries.

For example:

    export
    KDEDIR=/opt/kde
    export
    QTDIR=/usr/lib/qt2
    export
    PATH=$KDEDIR/bin:$QTDIR/bin:$PATH
    export
    LD_LIBRARY_PATH=$KDEDIR/lib:$QTDIR/lib

If you are still unsuccessful, try starting &xdm; instead, to make sure that you are not suffering from a more serious X configuration problem.

When you are able to start &kdm; successfully, you can start to replace &xdm; by &kdm;. Again, this is distribution-dependent.

- For &RedHat;, edit `/etc/inittab`, look for the string xdm and replace it with &kdm; (including all paths).

- For &Mandrake;, the X11 runlevel in `/etc/inittab` invokes the shell script `/etc/X11/prefdm`, which is set up to select from amongst several display managers, including &kdm;. Make sure that all the paths are correct for your installation.

- For &SuSE;, edit `/sbin/init.d/xdm` to add a first line:

      . /etc/rc.config
      DISPLAYMANAGER=kdm
      export DISPLAYMANAGER

- For FreeBSD, edit `/etc/ttys` and find the line like this:

      ttyv8   "/usr/X11R6/bin/xdm -nodaemon"  xterm   off secure

  and edit it to this:

      ttyv8   "/usr/local/bin/kdm -nodaemon"  xterm   on secure

- Most other distributions are a variation of one of these.

At this stage, you can test &kdm; again by bringing your system to the runlevel that should now run &kdm;. To do so, issue a command like this:

    /sbin/init 5

Instead of the number `5` you should specify the appropriate runlevel for running X11 on your system.

The final step is to edit the `initdefault` entry in `/etc/inittab` to specify the appropriate runlevel for X11.

Before you make this change, ensure that you have a way to reboot your system if a problem occurs. This might be a rescue floppy-disk provided by your operating system distribution or a specially-designed rescue floppy-disk, such as `tomsrtbt`. Ignore this advice at your peril.

When you reboot your system, you should end up with the graphical &kdm; login dialogue.

If this step is unsuccessful the most likely problem is that the environment used at boot time differs from the environment that you used for testing at the command line. If you are trying to get two versions of KDE to co-exist, be particularly careful that the settings you use for your `PATH` and `LD_LIBRARY_PATH` environment variables are consistent, and that the startup scripts are not over-riding them in some way.

## Supporting multiple window managers

The main dialogue box for &kdm; includes a Session Type: drop-down box, which allows you to select a window manager to use for your session. This chapter describes the changes that you must make to your configuration files in order to support this feature.

The options that appear in the Session Type: drop-down box are configured by entries in the `KDM` section of &kdmrc;.

When you log in using &kdm;, the shell script `Xsession` is executed. The session type that you select is passed as a command-line argument. (`Xsession` can be found in `/etc/X11/xdm/` for Redhat and Mandrake, and in `/usr/X11R6/lib/X11/xdm/` for S.u.S.E.). Whilst debugging, you might find it helpful to add this line to `Xsession`:

    echo "$0 || $1 || $2"
    > $HOME/.Xsession_args

How you proceed now depends upon how your system usually starts up window managers. Here are two different approaches, with examples of the changes that you must make:

- The window manager is started by commands within `Xsession`. In this case, you can add a case statement to start the appropriate window manager. Linux Mandrake uses this approach; here is an extract from `Xsession`:

      # now, we see if xdm/gdm/kdm has asked for a specific environment
      case $# in
      1)
          case $1 in
              kde)
              source /opt/kde2/bin/kde1
              exec startkde
              ;;
              kde2)
              source /opt/kde2/bin/kde2
              exec startkde
              ;;
                  failsafe)
              exec xterm -geometry 80x24-0-0
              ;;
              default)
              ;;
              *)
              exec /bin/sh -c "$(/usr/sbin/chksession -x=$1)"
              ;;
           esac
      esac

- The window manager is started by another script that is invoked by `Xsession`. In this case you must ensure that the parameter passed to `Xsession` is passed on to that other script. For example, if the window manager is started like this:

      exec $startup

  you would need to change it to:

      exec $startup$@

  Having made this change, you must trace your way through the startup to find the place where the window manager is started. One approach uses `xinitrc` to start the window manager; this allows a system-wide file `/etc/X11/xinit/xinitrc` or a user-specific file `$HOME/.xinitrc` to be used. If you edit `$HOME/.xinitrc`, you may want to save a copy in `/etc/skel`, so that it will be automatically generated in every user account you create from now on. Here is an example `xinitrc` for a system using this approach:

      #!/bin/bash
      #
      # .xsession/.xinitrc
      #
      # choose a window manager
      #

      defaultwm=kde
      #set the window manager to $1 if it was supplied
      windowmgr=${1:-$defaultwm}

      #start the respective window managers
      case ${windowmgr} in
        kde|kwm|kdestart)
              WINDOWMANAGER=startkde
              ;;
        fvwm|fvwm2)
              WINDOWMANAGER=fvwm2
              ;;

        fvwm95)
              WINDOWMANAGER=fvwm95
              ;;

        *)    WINDOWMANAGER=windowmgr   # default for unknown wm's

      esac

      #
      # load resources
      #

      if [ -f /usr/X11R6/lib/X11/Xmodmap ]; then
          xmodmap /usr/X11R6/lib/X11/Xmodmap
      fi

      if [ -f ~/.Xmodmap ]; then
          xmodmap ~/.Xmodmap
      fi

      if [ -f ~/.Xdefaults ]; then
          xrdb -merge ~/.Xdefaults
      fi

      if [ -f ~/.Xresources ]; then
          xrdb -merge ~/.Xresources
      fi
      #
      # finally start the window manager
      #
      exec $WINDOWMANAGER

## Using &kdm; for Remote Logins (&XDMCP;)

&XDMCP; is the Open Group standard, the X Display Manager Control Protocol. This is used to set up connections between remote systems over the network.

&XDMCP; is useful in multiuser situations where there are users with workstations and a more powerful server that can provide the resources to run multiple X sessions. For example, &XDMCP; is a good way to reuse old computers - a Pentium or even 486 computer with 16 Mb RAM is sufficient to run X itself, and using XDMCP such a computer can run a full modern &kde; session from a server. For the server part, once a single &kde; (or other environment) session is running, running another one requires very few extra resources.

However, allowing another method of login to your machine obviously has security implications. You should run this service only if you need to allow remote X Servers to start login sessions on your system. Users with a single &UNIX; computer should not need to run this.

## Other sources of information

Since &kdm; is descended from &xdm;, the xdm man page may provide useful background information. For X-related problems try the man pages X and startx. If you have questions about &kdm; that are not answered by this handbook, take advantage of the fact the &kdm; is provided under the terms of the GNU General Public Licence: look at the source code.

## Credits and Licence

&kdm; is derived from, and includes code from, &xdm; (C) Keith Packard, MIT X Consortium.

&kdm; 0.1 was written by Matthias Ettrich. Later versions till &kde; 2.0.x were written by Steffen Hansen. Some new features for &kde; 2.1.x and a major rewrite for &kde; 2.2.x made by Oswald Buddenhagen.

Other parts of the &kdm; code are copyright by the authors, and licensed under the terms of the GNU GPL. Anyone is allowed to change &kdm; and redistribute the result as long as the names of the authors are mentioned.

&kdm; requires the Qt library, which is copyright Troll Tech AS.

Documentation contributors:

- Documentation written by Steffen Hansen stefh@dit.ou.dk

- Documentation extended by Gregor Zumsteinzumstein@ssd.ethz.ch. Last update August 9, 1998

- Documentation revised for KDE 2 by Neal Crooknac@forth.org. Last update August 6, 2000

- Documentation extended and revised for KDE 2.2 by Oswald Buddenhagenossi@kde.org. Last update August, 2001

Documentation copyright Steffen Hansen, Gregor Zumstein, Neal Crook and Oswald Buddenhagen. This document also includes large parts of the &xdm; man page, which is (C) Keith Packard.

Conversion to British English: John Knight anarchist_tomato@herzeleid.net

&underFDL; &underGPL;

## Building and Installing kdm

&kdm; is part of the KDE project. The various component parts of the KDE project are broken into sections, called packages. &kdm; is part of the package called kdebase. You can get KDE source code from various Linux and BSD distribution CDs, or by download from www.kde.org or its mirrors. If you have an out-of-date source code tree, you can use one of the KDE cvsup servers to bring it up-to-date whilst using minimal network bandwidth.

Before building kdebase, you must have built and installed (in this order) version 2 of the qt library and the KDE packages kdesupport (optionally) and kdelibs.

In order to build any of the above, you must already have the X Window System installed, together with a C++ compiler. If are you building from CVS you will also need the GNU configuration tools automake and autoconf.

If the last few paragraphs seemed like a foreign language, then either you have strayed into an Inappropriate Area of this handbook, or you are about to undergo a Great Learning Experience.

If you managed to satisfy all of the prerequisites, you are unlikely to have any problems with building and installing kdebase. &kdm; is installed in your `$KDEDIR/bin` folder.

`make `install`` will not overwrite your previous &kdm; config files including &kdmrc;.

## Glossary

greeter

The greeter is the login dialogue, &ie; the part of &kdm; which the user sees.

entropy

...