1wdm(1x) wdm(1x)
2
6 wdm - WINGs Display Manager
7
9 wdm [ options ]
10
12 wdm is an X display manager based on the original X11 X Display Manager
13 (xdm). It features numerous functionality improvements, including the
14 ability
15 to reboot or halt the machine (once the proper password has been sup‐
16 plied) and to select from a list of available X sessions to start. The
17 look of the login panel is somewhat configurable, too.
18
20 Except for -config, all of these options can be specified as resources.
21 -config configuration_file
23 Names the configuration file, which specifies resources to con‐
24 trol the behavior of wdm. #configdir#/wdm-config is the default.
25 -nodaemon
27 Specifies ``false'' as the value for the DisplayManager.daemon‐
28 Mode resource. This suppresses the normal daemon behavior, which
29 is for wdm to close all file descriptors, disassociate itself
30 from the controlling terminal, and put itself in the background
31 when it first starts up.
32 -debug debug_level
34 Specifies the numeric value for the DisplayManager.debugLevel
35 resource. A non-zero value causes wdm to print lots of debug‐
36 ging statements to the terminal; it also disables the Display‐
37 Manager.daemonMode resource, forcing wdm to run synchronously.
38 To interpret these debugging messages, a copy of the source code
39 for wdm is almost a necessity. No attempt has been made to
40 rationalize or standardize the output.
41 -error error_log_file
43 Specifies the value for the DisplayManager.errorLogFile
44 resource. This file contains errors from wdm as well as any‐
45 thing written to stderr by the various scripts and programs run
46 during the progress of the session.
47 -syslog facility
49 Specifies the value for the DisplayManager.syslogFacility
50 resource. This is factility to use with all messages if log is
51 redirected to syslog.
52 -usesyslog
54 Specifies ``true'' as the value for the
55 DisplayManager.useSyslogP resource. This will force all messages
56 go to syslog with facility specified by DisplayManager.syslogFa‐
57 cility resource.
58 -useerrfile
60 Specifies ``false'' as the value for the DisplayManager.useSys‐
61 logP resource. This will force all messages go to log file spec‐
62 ified by DisplayManager.errorLogFile resource.
63 -resources resource_file
65 Specifies the value for the DisplayManager*resources resource.
66 This file is loaded using xrdb to specify configuration parame‐
67 ters for the authentication widget.
68 -server server_entry
70 Specifies the value for the DisplayManager.servers resource.
71 -udpPort port_number
73 Specifies the value for the DisplayManager.requestPort resource.
74 This sets the port-number which wdm will monitor for XDMCP
75 requests. As XDMCP uses the registered well-known UDP port 177,
76 this resource should not be changed except for debugging. If set
77 to 0 wdm will not listen for XDMCP or Chooser requests.
78 -session session_program
80 Specifies the value for the DisplayManager*session resource.
81 This indicates the program to run as the session after the user
82 has logged in.
83 -xrm resource_specification
85 Allows an arbitrary resource to be specified, as in most X Tool‐
86 kit applications.
87
89 At many stages the actions of wdm can be controlled through the use of
90 its configuration file, which is in the X resource format. Some
91 resources modify the behavior of wdm on all displays, while others mod‐
92 ify its behavior on a single display. Where actions relate to a spe‐
93 cific display, the display name is inserted into the resource name
94 between ``DisplayManager'' and the final resource name segment.
95 For local displays, the resource name and class are as read from the
97 Xservers file.
98 For remote displays, the resource name is what the network address of
100 the display resolves to. See the removeDomain resource. The name must
101 match exactly; wdm is not aware of all the network aliases that might
102 reach a given display. If the name resolve fails, the address is used.
103 The resource class is as sent by the display in the XDMCP Manage
104 request.
105 Because the resource manager uses colons to separate the name of the
107 resource from its value and dots to separate resource name parts, wdm
108 substitutes underscores for both dots and colons when generating the
109 resource name. For example, DisplayManager.expo_x_org_0.startup is the
110 name of the resource which defines the startup shell file for the
111 ``expo.x.org:0'' display.
112 DisplayManager.servers
114 This resource either specifies a file name full of server
115 entries, one per line (if the value starts with a slash), or a
116 single server entry. See the section Local Server Specification
117 for the details.
118 DisplayManager.requestPort
120 This indicates the UDP port number which wdm uses to listen for
121 incoming XDMCP requests. Unless you need to debug the system,
122 leave this with its default value of 177.
123 DisplayManager.errorLogFile
125 Error output is normally directed at the system console. To re‐
126 direct it, set this resource to a file name. A method to send
127 these messages to syslog should be developed for systems which
128 support it; however, the wide variety of interfaces precludes
129 any system-independent implementation. This file also contains
130 any output directed to stderr by the Xsetup, Xstartup, Xsession
131 and Xreset files, so it will contain descriptions of problems in
132 those scripts as well.
133 DisplayManager.debugLevel
135 If the integer value of this resource is greater than zero,
136 reams of debugging information will be printed. It also dis‐
137 ables daemon mode, which would redirect the information into the
138 bit-bucket, and allows non-root users to run wdm, which would
139 normally not be useful.
140 DisplayManager.daemonMode
142 Normally, wdm attempts to make itself into a daemon process
143 unassociated with any terminal. This is accomplished by forking
144 and leaving the parent process to exit, then closing file
145 descriptors and releasing the controlling terminal. In some
146 environments this is not desired (in particular, when debug‐
147 ging). Setting this resource to ``false'' will disable this
148 feature.
149 DisplayManager.pidFile
151 The filename specified will be created to contain an ASCII rep‐
152 resentation of the process-id of the main wdm process. Xdm also
153 uses file locking on this file to attempt to eliminate multiple
154 daemons running on the same machine, which would cause quite a
155 bit of havoc.
156 DisplayManager.lockPidFile
158 This is the resource which controls whether wdm uses file lock‐
159 ing to keep multiple display managers from running amok. On
160 System V, this uses the lockf library call, while on BSD it uses
161 flock.
162 DisplayManager.authDir
164 This names a directory under which wdm stores authorization
165 files while initializing the session. The default value is
166 #configdir#. Can be overridden for specific displays by Dis‐
167 playManager.DISPLAY.authFile.
168 DisplayManager.autoRescan
170 This boolean controls whether wdm rescans the configuration,
171 servers, access control and authentication keys files after a
172 session terminates and the files have changed. By default it is
173 ``true.'' You can force wdm to reread these files by sending a
174 SIGHUP to the main process.
175 DisplayManager.removeDomainname
177 When computing the display name for XDMCP clients, the name
178 resolver will typically create a fully qualified host name for
179 the terminal. As this is sometimes confusing, wdm will remove
180 the domain name portion of the host name if it is the same as
181 the domain name of the local host when this variable is set. By
182 default the value is ``true.''
183 DisplayManager.keyFile
185 XDM-AUTHENTICATION-1 style XDMCP authentication requires that a
186 private key be shared between wdm and the terminal. This
187 resource specifies the file containing those values. Each entry
188 in the file consists of a display name and the shared key. By
189 default, wdm does not include support for XDM-AUTHENTICATION-1,
190 as it requires DES which is not generally distributable because
191 of United States export restrictions.
192 DisplayManager.accessFile
194 To prevent unauthorized XDMCP service and to allow forwarding of
195 XDMCP IndirectQuery requests, this file contains a database of
196 hostnames which are either allowed direct access to this
197 machine, or have a list of hosts to which queries should be for‐
198 warded to. The format of this file is described in the section
199 XDMCP Access Control.
200 DisplayManager.exportList
202 A list of additional environment variables, separated by white
203 space, to pass on to the Xsetup, Xstartup, Xsession, and Xreset
204 programs.
205 DisplayManager.randomFile
207 A file to checksum to generate the seed of authorization keys.
208 This should be a file that changes frequently. The default is
209 /dev/mem.
210 DisplayManager.greeterLib
212 On systems that support a dynamically-loadable greeter library,
213 the name of the library. The default is /usr/lib/X11/xdm/libXd‐
214 mGreet.so. This not used in Debian.
215 DisplayManager.choiceTimeout
217 Number of seconds to wait for display to respond after user has
218 selected a host from the chooser. If the display sends an XDMCP
219 IndirectQuery within this time, the request is forwarded to the
220 chosen host. Otherwise, it is assumed to be from a new session
221 and the chooser is offered again. Default is 15.
222 DisplayManager.sourceAddress
224 Use the numeric IP address of the incoming connection on multi‐
225 homed hosts instead of the host name. This is to avoid trying to
226 connect on the wrong interface which might be down at this time.
227 DisplayManager.willing
229 This specifies a program which is run (as) root when an an XDMCP
230 BroadcastQuery is received and this host is configured to offer
231 XDMCP display management. The output of this program may be dis‐
232 played on a chooser window. If no program is specified, the
233 string Willing to manage is sent.
234 DisplayManager.DISPLAY.resources
236 This resource specifies the name of the file to be loaded by
237 xrdb as the resource database onto the root window of screen 0
238 of the display. The Xsetup program, the Login widget, and
239 chooser will use the resources set in this file. This resource
240 data base is loaded just before the authentication procedure is
241 started, so it can control the appearance of the login window.
242 See the section Authentication Widget, which describes the vari‐
243 ous resources that are appropriate to place in this file. There
244 is no default value for this resource, but #configdir#/Xre‐
245 sources is the conventional name.
246 DisplayManager.DISPLAY.chooser
248 Specifies the program run to offer a host menu for Indirect
249 queries redirected to the special host name CHOOSER.
250 /usr/X11R6/bin/chooser is the default. See the sections XDMCP
251 Access Control and Chooser.
252 DisplayManager.DISPLAY.xrdb
254 Specifies the program used to load the resources. By default,
255 wdm uses /usr/X11R6/bin/xrdb.
256 DisplayManager.DISPLAY.cpp
258 This specifies the name of the C preprocessor which is used by
259 xrdb.
260 DisplayManager.DISPLAY.setup
262 This specifies a program which is run (as root) before offering
263 the Login window. This may be used to change the appearance of
264 the screen around the Login window or to put up other windows
265 (e.g., you may want to run xconsole here). By default, no pro‐
266 gram is run. The conventional name for a file used here is
267 Xsetup. See the section Setup Program.
268 DisplayManager.DISPLAY.startup
270 This specifies a program which is run (as root) after the
271 authentication process succeeds. By default, no program is run.
272 The conventional name for a file used here is Xstartup. See the
273 section Startup Program.
274 DisplayManager.DISPLAY.session
276 This specifies the session to be executed (not running as root).
277 By default, /usr/X11R6/bin/xterm is run. The conventional name
278 is Xsession. See the section Session Program.
279 DisplayManager.DISPLAY.reset
281 This specifies a program which is run (as root) after the ses‐
282 sion terminates. By default, no program is run. The conven‐
283 tional name is Xreset. See the section Reset Program.
284 DisplayManager.DISPLAY.openDelay
286 DisplayManager.DISPLAY.openRepeat
288 DisplayManager.DISPLAY.openTimeout
290 DisplayManager.DISPLAY.startAttempts
292 These numeric resources control the behavior of wdm when
293 attempting to open intransigent servers. openDelay is the
294 length of the pause (in seconds) between successive attempts,
295 openRepeat is the number of attempts to make, openTimeout is the
296 amount of time to wait while actually attempting the open (i.e.,
297 the maximum time spent in the connect(2) system call) and star‐
298 tAttempts is the number of times this entire process is done
299 before giving up on the server. After openRepeat attempts have
300 been made, or if openTimeout seconds elapse in any particular
301 attempt, wdm terminates and restarts the server, attempting to
302 connect again. This process is repeated startAttempts times, at
303 which point the display is declared dead and disabled. Although
304 this behavior may seem arbitrary, it has been empirically devel‐
305 oped and works quite well on most systems. The default values
306 are 5 for openDelay, 5 for openRepeat, 30 for openTimeout and 4
307 for startAttempts.
308 DisplayManager.DISPLAY.pingInterval
310 DisplayManager.DISPLAY.pingTimeout
312 To discover when remote displays disappear, wdm occasionally
313 pings them, using an X connection and XSync calls. pingInterval
314 specifies the time (in minutes) between each ping attempt, ping‐
315 Timeout specifies the maximum amount of time (in minutes) to
316 wait for the terminal to respond to the request. If the termi‐
317 nal does not respond, the session is declared dead and termi‐
318 nated. By default, both are set to 5 minutes. If you fre‐
319 quently use X terminals which can become isolated from the man‐
320 aging host, you may wish to increase this value. The only worry
321 is that sessions will continue to exist after the terminal has
322 been accidentally disabled. wdm will not ping local displays.
323 Although it would seem harmless, it is unpleasant when the work‐
324 station session is terminated as a result of the server hanging
325 for NFS service and not responding to the ping.
326 DisplayManager.DISPLAY.terminateServer
328 This boolean resource specifies whether the X server should be
329 terminated when a session terminates (instead of resetting it).
330 This option can be used when the server tends to grow without
331 bound over time, in order to limit the amount of time the server
332 is run. The default value is ``false.''
333 DisplayManager.DISPLAY.userPath
335 Xdm sets the PATH environment variable for the session to this
336 value. It should be a colon separated list of directories; see
337 sh(1) for a full description.
338 ``:/bin:/usr/bin:/usr/X11R6/bin:/usr/ucb'' is a common setting.
339 The default value can be specified at build time in the X system
340 configuration file with DefaultUserPath.
341 DisplayManager.DISPLAY.systemPath
343 Xdm sets the PATH environment variable for the startup and reset
344 scripts to the value of this resource. The default for this
345 resource is specified at build time by the DefaultSystemPath
346 entry in the system configuration file;
347 ``/etc:/bin:/usr/bin:/usr/X11R6/bin:/usr/ucb'' is a common
348 choice. Note the absence of ``.'' from this entry. This is a
349 good practice to follow for root; it avoids many common Trojan
350 Horse system penetration schemes.
351 DisplayManager.DISPLAY.systemShell
353 Xdm sets the SHELL environment variable for the startup and
354 reset scripts to the value of this resource. It is /bin/sh by
355 default.
356 DisplayManager.DISPLAY.failsafeClient
358 If the default session fails to execute, wdm will fall back to
359 this program. This program is executed with no arguments, but
360 executes using the same environment variables as the session
361 would have had (see the section Session Program). By default,
362 /usr/X11R6/bin/xterm is used.
363 DisplayManager.DISPLAY.grabServer
365 DisplayManager.DISPLAY.grabTimeout
367 To improve security, wdm grabs the server and keyboard while
368 reading the login name and password. The grabServer resource
369 specifies if the server should be held for the duration of the
370 name/password reading. When ``false,'' the server is ungrabbed
371 after the keyboard grab succeeds, otherwise the server is
372 grabbed until just before the session begins. The default is
373 ``false.'' The grabTimeout resource specifies the maximum time
374 wdm will wait for the grab to succeed. The grab may fail if
375 some other client has the server grabbed, or possibly if the
376 network latencies are very high. This resource has a default
377 value of 3 seconds; you should be cautious when raising it, as a
378 user can be spoofed by a look-alike window on the display. If
379 the grab fails, wdm kills and restarts the server (if possible)
380 and the session.
381 DisplayManager.DISPLAY.authorize
383 DisplayManager.DISPLAY.authName
385 authorize is a boolean resource which controls whether wdm gen‐
386 erates and uses authorization for the local server connections.
387 If authorization is used, authName is a list of authorization
388 mechanisms to use, separated by white space. XDMCP connections
389 dynamically specify which authorization mechanisms are sup‐
390 ported, so authName is ignored in this case. When authorize is
391 set for a display and authorization is not available, the user
392 is informed by having a different message displayed in the login
393 widget. By default, authorize is ``true.'' authName is ``MIT-
394 MAGIC-COOKIE-1,'' or, if XDM-AUTHORIZATION-1 is available,
395 ``XDM-AUTHORIZATION-1 MIT-MAGIC-COOKIE-1.''
396 DisplayManager.DISPLAY.authFile
398 This file is used to communicate the authorization data from wdm
399 to the server, using the -auth server command line option. It
400 should be kept in a directory which is not world-writable as it
401 could easily be removed, disabling the authorization mechanism
402 in the server. If not specified, a name is generated from Dis‐
403 playManager.authDir and the name of the display.
404 DisplayManager.DISPLAY.authComplain
406 If set to ``false,'' disables the use of the unsecureGreeting in
407 the login window. See the section Authentication Widget. The
408 default is ``true.''
409 DisplayManager.DISPLAY.resetSignal
411 The number of the signal wdm sends to reset the server. See the
412 section Controlling the Server. The default is 1 (SIGHUP).
413 DisplayManager.DISPLAY.termSignal
415 The number of the signal wdm sends to terminate the server. See
416 the section Controlling the Server. The default is 15
417 (SIGTERM).
418 DisplayManager.DISPLAY.resetForAuth
420 The original implementation of authorization in the sample
421 server reread the authorization file at server reset time,
422 instead of when checking the initial connection. As wdm gener‐
423 ates the authorization information just before connecting to the
424 display, an old server would not get up-to-date authorization
425 information. This resource causes wdm to send SIGHUP to the
426 server after setting up the file, causing an additional server
427 reset to occur, during which time the new authorization informa‐
428 tion will be read. The default is ``false,'' which will work
429 for all MIT servers.
430 DisplayManager.DISPLAY.userAuthDir
432 When wdm is unable to write to the usual user authorization file
433 ($HOME/.Xauthority), it creates a unique file name in this
434 directory and points the environment variable XAUTHORITY at the
435 created file. It uses /tmp by default.
436 DisplayManager.wdmLogin
438 Specifies the path to wdmLogin(1x)
439 DisplayManager.wdmWm
441 Is a colon separated list of window managers to use as options
442 in the login panel. Note that if you include the path to the
443 window manager, it will look ugly. You may set this resource to
444 None if you want only NoChange to appear.
445 DisplayManager.wdmLogo
447 Path to the logo pixmap, several formats are accepted, read wdm‐
448 Login(1x) to find out more.
449 DisplayManager.wdmHelpFile
451 Path to a text file which will be displayed in the help panel,
452 read wdmLogin(1x) to find out more.
453 DisplayManager.wdmDefaultUser
455 a default username which will be used if no username is typed.
456 DisplayManager.wdmDefaultPasswd
458 the clear text password of the default user above. BE VERY CARE‐
459 FUL when using this two resources, and don't forget to do: chmod
460 600 wdm-config ; chown root.root wdm-config
461 DisplayManager.wdmBg
463 Background specification. Read the BACKGROUND IMAGE SPECIFICA‐
464 TION section to find out about the format. If this is not spec‐
465 ified, then the background is not set.
466 DisplayManager.wdmReboot
468 Reboot command.
469 DisplayManager.wdmHalt
471 Halt command.
472 DisplayManager.wdmVerify
474 If true, verify user's identity for reboot/halt/exit.
475 DisplayManager.wdmRoot
477 If true, user must be root to exit.
478 DisplayManager.wdmAnimations
480 If true, enable animations consisting of shaking the panel (if
481 an error) and rolling up the panel (when closing it). If false,
482 animations are disabled.
483 DisplayManager.wdmLocale
485 LANG environment variable will be set to value of this resource
486 before starting wdmLogin.
487 DisplayManger.wdmCursorTheme
489 If you have recent version of XFree with support for transparent
490 cursors you can select cursor theme to use on login panel.
491 XCURSOR_THEME environment variable will be set to value of this
492 resource before starting wdmLogin.
493
495 The default location of the wdm configuration file is #configdir#/wdm-
496 config
497 Here is a reasonable configuration file, which could be named wdm-con‐
499 fig:
500 DisplayManager.servers: /usr/X11R6/lib/X11/xdm/Xservers
503 DisplayManager.errorLogFile: /usr/X11R6/lib/X11/xdm/xdm-errors
504 DisplayManager*resources: /usr/X11R6/lib/X11/xdm/Xresources
505 DisplayManager*startup: /usr/X11R6/lib/X11/xdm/Xstartup
506 DisplayManager*session: /usr/X11R6/lib/X11/xdm/Xsession
507 DisplayManager.pidFile: /usr/X11R6/lib/X11/xdm/xdm-pid
508 DisplayManager._0.authorize: true
509 DisplayManager*authorize: false
510 Note that this file mostly contains references to other files. Note
513 also that some of the resources are specified with ``*'' separating the
514 components. These resources can be made unique for each different dis‐
515 play, by replacing the ``*'' with the display-name, but normally this
516 is not very useful. See the Resources section for a complete discus‐
517 sion. If the entry is a host name, all comparisons are done using net‐
518 work addresses, so any name which converts to the correct network
519 address may be used. For patterns, only canonical host names are used
520 in the comparison, so ensure that you do not attempt to match aliases.
521 Preceding either a host name or a pattern with a `!' character causes
522 hosts which match that entry to be excluded.
523 To only respond to Direct queries for a host or pattern, it can be fol‐
525 lowed by the optional ``NOBROADCAST'' keyword. This can be used to
526 prevent an wdm server from appearing on menus based on Broadcast
527 queries.
528 An Indirect entry also contains a host name or pattern, but follows it
530 with a list of host names or macros to which indirect queries should be
531 sent.
532 A macro definition contains a macro name and a list of host names and
534 other macros that the macro expands to. To distinguish macros from
535 hostnames, macro names start with a `%' character. Macros may be
536 nested.
537 Indirect entries may also specify to have wdm run chooser to offer a
539 menu of hosts to connect to. See the section Chooser.
540 When checking access for a particular display host, each entry is
542 scanned in turn and the first matching entry determines the response.
543 Direct and Broadcast entries are ignored when scanning for an Indirect
544 entry and vice-versa.
545 Blank lines are ignored, `#' is treated as a comment delimiter causing
547 the rest of that line to be ignored, and `\newline' causes the newline
548 to be ignored, allowing indirect host lists to span multiple lines.
549 Here is an example Xaccess file:
551 #
553 # Xaccess - XDMCP access control file
554 #
555 #
557 # Direct/Broadcast query entries
558 #
559 !xtra.lcs.mit.edu # disallow direct/broadcast service for xtra
561 bambi.ogi.edu # allow access from this particular display
562 *.lcs.mit.edu # allow access from any display in LCS
563 *.deshaw.com NOBROADCAST # allow only direct access
565 *.gw.com # allow direct and broadcast
566 #
568 # Indirect query entries
569 #
570 %HOSTS expo.lcs.mit.edu xenon.lcs.mit.edu \
572 excess.lcs.mit.edu kanga.lcs.mit.edu
573 extract.lcs.mit.edu xenon.lcs.mit.edu #force extract to contact xenon
575 !xtra.lcs.mit.edu dummy #disallow indirect access
576 *.lcs.mit.edu %HOSTS #all others get to choose
577
579 The Xresources file is loaded onto the display as a resource database
580 using xrdb. As the authentication widget reads this database before
581 starting up, it usually contains parameters for that widget:
582 xlogin*login.translations: #override\
584 Ctrl<Key>R: abort-display()\n\
585 <Key>F1: set-session-argument(failsafe) finish-field()\n\
586 <Key>Return: set-session-argument() finish-field()
587 xlogin*borderWidth: 3
588 xlogin*greeting: CLIENTHOST
589 #ifdef COLOR
590 xlogin*greetColor: CadetBlue
591 xlogin*failColor: red
592 #endif
593 Please note the translations entry; it specifies a few new translations
596 for the widget which allow users to escape from the default session
597 (and avoid troubles that may occur in it). Note that if #override is
598 not specified, the default translations are removed and replaced by the
599 new value, not a very useful result as some of the default translations
600 are quite useful (such as ``<Key>: insert-char ()'' which responds to
601 normal typing).
602 This file may also contain resources for the setup program and chooser.
604
606 The Xsetup file is run after the server is reset, but before the Login
607 window is offered. The file is typically a shell script. It is run as
608 root, so should be careful about security. This is the place to change
609 the root background or bring up other windows that should appear on the
610 screen along with the Login widget.
611 In addition to any specified by DisplayManager.exportList, the follow‐
613 ing environment variables are passed:
614 DISPLAY the associated display name
616 PATH the value of DisplayManager.DISPLAY.systemPath
617 SHELL the value of DisplayManager.DISPLAY.systemShell
618 XAUTHORITY may be set to an authority file
619 Note that since wdm grabs the keyboard, any other windows will not be
621 able to receive keyboard input. They will be able to interact with the
622 mouse, however; beware of potential security holes here. If Display‐
623 Manager.DISPLAY.grabServer is set, Xsetup will not be able to connect
624 to the display at all. Resources for this program can be put into the
625 file named by DisplayManager.DISPLAY.resources.
626 Here is a sample Xsetup script:
628 #!/bin/sh
630 # Xsetup_0 - setup script for one workstation
631 xcmsdb < /usr/X11R6/lib/monitors/alex.0
632 xconsole -geometry 480x130-0-0 -notify -verbose -exitOnFail &
633
636 There are several possible ways of specifing a background image. The
637 generic format is type:image. type can be any of:
638 none The backgound is not set.
640 solid it renders a solid backgroud, and image is a color name
642 hgradient, vgradient, dgradient
644 a gradient (either horizontal, vertical or diagonal) will be
645 rendered. image is comma separated of color names, and any num‐
646 ber of colors can be specified.
647 pixmap a pixmap will be used for the background. image is the full path
649 to an image file (tiff, png, jpeg and xpm allowed) and it will
650 be scaled to use the full screen.
651
653 wdmLogin(1x)
654
656 wdm was written by Gene Czarcinski <genec@mindspring.com>. wdm is based
657 on work by Tom Rothamel and xdm, (c) 1988 X Consortium
658 This man page was written by Marcelo Magallon <mmagallo@debian.org> and
660 extensively modified by Noah Meyerhans <noahm@debian.org>. Much of the
661 content was taken from xdm's manual page.
662 July 2002 wdm(1x)