dtsession(1X)

NAME
dtsession - the CDE Session Manager

SYNOPSIS
dtsession [options]

NOTE : The dtsession client is automatically invoked by the DT Login Manager (dtlogin(1X)) via the Xsession script. If desired, dtsession may be started via the Xsession script on an existing X server.

NOTE : dtsession automatically starts a window manager.

DESCRIPTION
The dtsession client provides ICCCM 1.1 compliant session management functionality during a user's session, the time from login to logout. It launches a window manager and allows for saving a session, restoring a session, locking a session, launching screen savers and allocating colors for desktop compatible clients.

  Key Supported Tasks
The dtsession client supports the following key tasks:

    - Initializing a session.

    - Launching a window manager.

    - Restoring a `home' or `current' session.

    - Providing session locking on command or timeout.

    - Providing session screen saving on command or timeout.

    - Acting as a color allocation server for other DT clients.

    - Saving a `home' or `current' session.

    - Displaying confirmation dialog at logout.

    - Displaying session selection dialog at logout.

    - Terminating a session.

  A Session
A session is the collection of applications, settings and resources that are present on the user's desktop. Session management is a set of conventions and protocols that allow a special session manager such as dtsession to save and restore a user's session. A user is able to log into their system and be presented with the same set of running applications, settings and resources as were present when the user logged off. When a user logs into the desktop for the first time, a default initial session is loaded. Afterward, dtsession supports the notion of a current and a home session.

  The Initial Session
When a user logs into the desktop for the first time, dtsession will generate the user's initial session using system default values. Refer to Session Resource Management and Session Application Management for more information.

  The Current Session
The user's running session is always considered the current session, whether restored upon login from a saved home session, a saved current session or the system default initial session. Based on the user's Style Manager Startup settings, when the user exits the session, the current session is automatically saved. When the user next logs into the desktop, the previously saved current session is restarted. This means that the desktop will be restored to same state as it was when the user last logged out.

  The Home Session
Another option is having the desktop be restored to the same state every time the user logs in, regardless of its state when the user logged out. The user may save the state of the current session, then via the Style Manager Startup settings, have the desktop start that session every time the user logs in.

  Display-specific Sessions
To run a specific session for a specific display, a user may create a display-specific session. To do this, the user can copy the $HOME/.dt/sessions directory to $HOME/.dt/display where display is the real, unqualified hostname (for example, pablo:0 is valid, pablo.gato.com:0 or local:0 is not). When the user logs in on display pablo:0, that display specific session will take precedence.

  The ICCCM Session Management Protocol
For an application to be saved upon logout and restarted upon login, it must participate in a simple session management protocol. Dtsession supports the ICCCM 1.1 Session Management Protocol.

Applications that wish to save their state can take part in the WM_SAVE_YOURSELF protocol. To do this, an application needs to set the WM_SAVE_YOURSELF property on one and only one of its top-level windows. When a session is saved, dtsession will send the application's top-level window a WM_SAVE_YOURSELF client message. At this point the application can proceed to quietly save its state. The application cannot interact with the user in any way as it is saving its state. As an application will likely save its state into a file, the session manager provides a convenience function DtSessionSavePath() which returns a full pathname of a file in which an application can save its state. While the application is saving its state, dtsession is awaiting notice from the application that it is done. To tell dtsession that the state save is complete, the application needs to update the WM_COMMAND property on its top-level window.

The WM_COMMAND property on an application's top-level window serves two purposes. First, a change of this property is the indication to dtsession that an application is done saving its state and dtsession can proceed to the next application. Second, the WM_COMMAND property value is expected to contain the command line that dtsession will use to restart the application at session startup. If an application is launched with a full pathname, then it should use the full pathname when setting WM_COMMAND. Applications that do not need to save their state, but wish to be restarted, can simply set WM_COMMAND during application startup and forget about it.

Refer to the XmAddWmProtocols(), XmAddWMProtocolCallback() and XSetCommand() API's for more information.

  Restoring A Session
At session startup time, dtsession will determine which session to restore. The following describes the precedence:

- Display-specific Current or Home Session -OR-

- Current or Home Session -OR-

- Initial Session

  Session Resource Management
The session manager uses the X Server RESOURCE_MANAGER property on which to make available desktop resources to all applications. The session manager will load the RESOURCE_MANAGER in the following manner:

- load the system default resources -AND-

- merge any system administrator specified resources -AND-

- merge any user specified resources

The desktop default resources can be found in /usr/dt/config/$LANG/sys.resources. These resources will be made available to each user's session via the RESOURCE_MANAGER property. This file should not be edited as it will be unconditionally overwritten upon subsequent desktop installations.

A system administrator may augment the system default resources by creating /etc/dt/config/$LANG/sys.resources. In this file, a system administrator may override system default resources or specify additional resources. As this file is merged into the desktop default resources during session startup, it is preferrable that only new or updated resource specifications be placed in this file, rather than a copy being made of the desktop default resource file. Resources specified in this file will be made available to each user's session via the RESOURCE_MANAGER property. Resources specified in this file take precedence over those specified in the desktop default resource file.

A user may augment the desktop default and system administrator resources via their $HOME/.Xdefaults file. Resources specified in this file will be made available to only that user's session via the RESOURCE_MANAGER property. Resources specified in this file take precedence over those specified in the desktop default or system administrator resource files.

NOTE : The X Toolkit Intrinsics specifies that it will load resources for an application from either RESOURCE_MANAGER or from $HOME/.Xdefaults, but not both. Ordinarily, this would mean that the user's $HOME/.Xdefaults file would be ignored. However, the session manager accomodates $HOME/.Xdefaults by merging it into the RESOURCE_MANAGER at session startup as described above. If a user changes their $HOME/.Xdefaults, their changes will not be visible to new applications until the user invokes the ReloadResources action.

The ReloadResources action will instruct the session manager to reload the RESOURCE_MANAGER with the system, system administrator and user specified resources. This is useful to make available to new applications changes made to system administrator or user specified resource files.

See also dtresourcesfile(4) and dtsessionactions(5).

  Session Application Management
At session startup, the session manager will restart any applications that were saved as part of the session. The system default set of applications to be restored as part of the user's Initial Session can be found in /usr/dt/config/$LANG/sys.session. This file should not be edited as it will be unconditionally overwritten upon subsequent desktop installations.

See also dtsessionfile(4).

A system administrator may replace the set of applications that are restored as part of the user's Initial Session by creating a file named /etc/dt/config/$LANG/sys.session. Unlike the resource files, this file will be used as a complete replacement for the desktop default file, so it is valid to make a copy of the system default file and make any necessary modifications.

  The Window Manager
Dtsession is responsible for starting the window manager. By default /usr/dt/bin/dtwm is started. An alternate window manager can be specified with the wmStartupCommand resource. Refer to the Workspace Manager specification for more information.

  The Style Manager
The style manager provides the interface by which a user can change various desktop and X server settings for the current session. Refer to the Style Manager specification for more information.

  The Color Server
Dtsession serves as the color server for the desktop and provides a set of resources that can be used to configure it. The foregroundColor resource controls whether a pixel is allocated for the foreground color. The dynamicColor resource specifies whether read-only colors are allocated. The shadowPixmaps resource specifies whether colors are allocated for top shadow or bottom shadow. The colorUse resource limits color allocation. Finally, the writeXrdbColors resource specifies whether the *background and *foreground resources are placed in the resource database. See the Color Server Resources section and the Color Model specification for more information.

  Session Lock
Dtsession provides session locking. The current session can be locked directly by pressing the lock icon on the front panel. If supported by the X server, the current session can be locked after a specified period of inactivity. To unlock the session, the user must enter their login password.

By default, dtsession supports traditional local UNIX authentication for unlocking the session. Additional re-authentication function such as that required by DCE may be added by individual vendors.

  Screen Savers
Dtsession provides support for the launching of external screen savers as a part of session locking from the front panel or, if supported by the X server, after a specified period of inactivity. Refer to the Screen Saver specification for information as to how screen savers are integrated into the desktop.

  X Server Screen Saver Extensions
Dtsession's ability to provide session lock or screen saver launch after a specified period of inactivity depends upon the availability of an X server screen saver extension. Dtsession supports two such extensions:

    - X Consortium Sample X11 Screen Saver Extension 1.0

    - HP X Screen Saver Extension

The ability of dtsession to recognize both, either or none of these extensions is vendor specific.

  Launching The Session Manager
Dtsession should be launched from the Xsession script. Xsession is described in the login manager specification. It is recommended that Xsession be launched from dtlogin as part of the login sequence as is the default but there are alternative methods of starting Xsession:

dtlogin
    the default dtlogin configuration launches Xsession when a user logs in

proxy
    some systems will allow programs such as xinit, x11start or startx to start Xsession

OPTIONS
The dtsession client is automatically invoked by the DT Login Manager (dtlogin(1X)). If desired, dtsession may also be started on an existing X server. Note that dtsession automatically starts a window manager.

  -norestore
This option instructs dtsession not to restore a previous session nor save the session upon logout.

RETURN VALUE
 Exit values are:

0   Successful completion.

>1  Error condition occurred.

EXAMPLES

  dtsession -norestore
Start session manager from command line without restoring previous session.

RESOURCES

  Color Server

Name | Class | Value Type | Default
colorUse | ColorUse | String | DEFAULT
dynamicColor | DynamicColor | Boolean | True
foregroundColor | ForegroundColor | String | DYNAMIC
shadowPixmaps | ShadowPixmaps | String | DEFAULT
writeXrdbColors | WriteXrdbColors | Boolean | True

  Screen Lock/Screen Save

Name | Class | Value Type | Default
keys | Keys | unsigned char | NULL
passwordTimeout | passwordTimeout | unsigned int | 10

  Miscellaneous

Name | Class | Value Type | Default
queryServerSettings | QueryServerSettings | Boolean | False
saveFontPath | SaveFontPath | Boolean | False
wmStartupCommand | WmStartupCommand | executable path | NULL

  colorUse - DEFAULT
This resource specifies the number of colors to use for the user interface. Valid types are: Color server will determine type of monitor based upon number of display planes of the screen as follows:

1,2 B_W

4   LOW_COLOR

6   MEDIUM_COLOR

7+  HIGH_COLOR

B_W - Specifies a black and white system. The color palettes will use two color cells for the user interface. In this configuration only two color palettes are available: BlackWhite and WhiteBlack. These palettes cannot dynamically change. To change a palette, all applications using that color palette must be restarted. This resource value forces ShadowPixmaps to True, and ForegroundColor to either black or white depending on the palette chosen.

LOW_COLOR - Specifies a low color system. The color palettes will have two color sets and use a maximum of 12 color cells for the user interface, including black and white (color cells 0 and 1). The number of co ShadowPixmaps and ForegroundColor.

MEDIUM_COLOR - Specifies a medium color system. The color palettes will have 4 color sets and use a maximum of 22 color cells for the user interface, including black and white (color cells 0 and 1). The number of color cells can be reduced by using the resources ShadowPixmaps and ForegroundColor.

HIGH_COLOR - Specifies a high color system. The color palettes will have 8 color sets and use a maximum of 42 color cells for the user interface. including black and white (color cells 0 and 1). The number of color cells can be reduced by using the resources ShadowPixmaps and ForegroundColor.

  dynamicColor
This resource can have values of True or False. dynamicColor is used to reduce the number of color cells being used. Once a palette has been selected and it is not likely to be changed, dynamicColor can be set to False. If set to False colors cannot be dynamically changed using the DT style manager. A selected palette will take effect the next session. The next time the session comes up, the color server uses Read Only color cells that can be shared by all clients, thus reducing the number of color cells used.

  foregroundColor
This resource can have values of White, Black or Dynamic. ForegroundColor causes all text (foreground) to use either pixel 0 or 1 (Black or White) or to have a color cell dedicated to foreground and changes in response to the background color (Dynamic) for each ColorSet. If set to White or Black, the number of color cells used per ColorSet is reduced by 1.

  keys
This resource is a list of keyholders who have the ability to unlock the screen any time it is locked by the user. The list is a list of user id's separated by commas. For example if user kim has the following resource active during a session:

Dtsession*keys: fred,keith

Users fred and keith have the ability to unlock the display when kim locks it.

  passwordTimeout
This resource specifies (in seconds) the amount of time before the password dialog is removed from the screen. When the display is locked, the pointer shows a lock cursor, and a dialog appears which asks for the user password. If no activity from the pointer or keyboard is detected for passwordTimeout seconds, the dialog is removed from the screen. The dialog is redisplayed as soon as a pointer or keyboard event is detected. An passwordTimeout of 0 leaves the password dialog in place for the entire time the display is locked. The default value is 10 seconds.

  queryServerSettings
This resource specifies whether dtsession queries the server at logout for all its settings or saves only those settings set by using the DT Style Manager. Querying the server ensures that all settings are saved; however, there is a degradation in performance when a full query is done. The default value is False, which means that the server will not be queried.

  shadowPixmaps
For color systems, this resource can have a value of True or False. If True, topShadowColor and bottomShadowColor use the same pixel as background and topShadowPixmap and bottomShadowPixmap are specified instead of solid color to create the 3D look. This reduces the number of color cells per ColorSet by 2. ShadowPixmaps defaults to True for systems with 4 or less color planes (16 or less color cells), and False for systems with more than 4 color planes.

  wmStartupCommand
This resource allows for an alternate window manager to be started at login. If this resource is NULL , dtsession starts /usr/dt/bin/dtwm. An alternate startup might look like: Dtsession*wmStartupCommand: /usr/bin/X11/mwm

NOTE : that the command should not have any commands to a shell in it, and that it should not be surrounded by quotes. Also, if any other window manager other than dtwm is used, clients will be restored, but may not be restored to the correct position. By default, this resource contains a NULL value.

FILES

/usr/dt/config/$LANG/sys.session
    The desktop default set of applications for the user's Initial Session.

/etc/dt/config/$LANG/sys.session
    System Administrator specified set of applications for the user's Initial Session.

/usr/dt/config/$LANG/sys.resources
    The desktop default resources.

/etc/dt/config/$LANG/sys.resources
    System administrator specified resources.

$HOME/.Xdefaults
    User specified resources.

Dtsession stores session information in $HOME/.dt/display or $HOME/.dt/sessions. The content of these directories should not be directly edited by the user.

/usr/dt/app-defaults/$LANG/Dtsession
    Default dtsession resources.

SEE ALSO
See related specifications:

dtstyle
    Customization of many session properties

dtscreen
    Desktop screen savers

dtwm
    Window manager

dtlogin
    Login manager

dtsessionaction
    Session manager actions

dtsessionfile
    Format and location of desktop session files

dtresourcesfile
    Format and location of desktop resource files