xautolock-2.1: description + notes


Xautolock  monitors  console activity  under the X window system, and
fires  up  a  program  of your choice if  nothing  happens  during  a
user configurable  period of time.  You can use this to automatically
start up a screen locker in case you tend to forget to do so manually
before having a coffee break.

Xautolock  will  typically  be used to lock the screen but it  really
doesn't care what program you make it start. The only real assumption
made  by  xautolock  is that  a new countdown  starts  as soon as the
locker exits.


Just read the man page, it's really simple.

If you're on VMS, you should also check out the VMS.notes file.


If  xautolock  has been compiled to  support either the Xidle, or the
MIT ScreenSaver  extensions  (or both),  it first tries  to find  out
whether the X server also supports one of them. If it does, xautolock
will  periodically  call it to  determine the amount of time  elapsed
since the last input event, and will then base its actions upon that.

In the absence of both extensions, xautolock starts by traversing the
window tree,  selecting  SubstructureNotify on all windows and adding
each window to a temporary list.  About +- 30 seconds later, it scans
this  list,  asking  for  KeyPress  events.  However, it  takes  care
to interfere  as  little  as  possible  with  the  event  propagation
mechanism.  This is the  reason  for the  delay  between  the  moment
xautolock  learns  about  a new window  (and  consequently  asks  for
SubstructureNotify  events)  and  the  moment  it  asks for  KeyPress
events. Whenever a new window is created by an application, a similar
process takes place.  In contradiction  to what many people  believe,
this scheme does not cause a noticeable overhead.

In addition, xautolock periodically issues a  QueryPointer request in
order to  find out  whether  the pointer has moved  and implement the
"corners" feature as decribed in the man page.

If nothing happens within a user-specified period of time,  xautolock
will fire up a program  which is supposed  to lock the screen.  While
this program is running, xautolock itself remains on the look-out for
user interaction.


Important notice:  the first two bugs listed here are only present in
case xautolock  has been compiled with support for neither the  Xidle
nor the  MIT ScreenSaver  extensions,  or in case the X server  being
used does not support them.  They make up a good reason to get one of
these extensions installed.

 1. If, when creating a window,  an application waits for more than
    30 seconds before calling selecting KeyPress events on non-leaf
    windows,   xautolock  may interfere with the event  propagation
    mechanism.  This  effect  is  theoretical  and  has never  been
    observed  in real life.

 2. Xautolock  can not properly handle  the secure keyboard mode of
    xterm, since  that  will prevent any other  process,  including
    xautolock,  from  noticing  the  keyboard  events  aimed at the
    xterm.  Consequently, xautolock sometimes will think that there
    is no keyboard activity while in reality there is.

 3. Under some configurations, xautolock fails to exit upon logout.
    This  problem can occur  (but does not always do so)  under the
    following combined circumstances:

     + Xautolock is started in background from within a .xinitrc.
     + Your are trusting your windowmanager to kill all X processes
       when quitting  (which, by the way, is not a good idea).  One
       well known  source of problems in this area consists of olwm
       and its look-alikes.
     + The .xinitrc contains a "wait"  statement to make it collect
       all background processes upon logout.

    The  simplest workround for this problem is to start  xautolock
    from within a subshell. I.e. use this:

      ( xautolock & )

    On Solaris  an alternative solution  (which basically works  in
    exactly the same way) is to use this:

      toolwait xautolock

 4. The -disable,  -enable,  -toggle,  -exit, -locknow, -unlocknow,
    and  -restart  options  depend on  access to the X server to do
    their work.  This implies  that  they will be suspended in case
    some other application has grabbed the server all for itself.

 5. Xautolock  does not check  whether  the screen locker specified
    actually is available.

 6. The xautolock resources have a dummy resource classes.

If you can find others, please notify eyckmans@imec.be.

Note that,  while  I still scan most  X related newsgroups,  I do not
actually  read  them on a  regular basis  anymore,  as X no longer is
a part of my job.  I do still  actively  support xautolock on a daily
basis, though.  Hence you are  much more likely to get  quick help if
you contact me directly.

It looks like there is a bug in  the event management code of some  X
servers  (amongst  which  both  X11R4 and  X11R5 on older versions of
SunOS).  If you are using  version 1.7 of xautolock (previously known
as patchlevel 7), it is best to reset  the server before switching to
version 1.8 or later.  If you fail to do so, an old  version 1.7  bug
may  still show up.  (Some keyboard  events were  being  hijacked  by
version 1.7  of  =================

The  contrib  directory may  contain  various patches  that have been
contributed over time. If a patch is in there, I have for some reason
or  another decided not to include it in xautolock proper,  but still
consider  it to be sufficiently usefull  to other people  in order to
add it to the distribution.

Note  that the contents of  the contrib directory are  *not*  part of
xautolock. Each of the contributions lives under its own copyright.

In version 2.1 of xautolock,  the contrib  directory is empty,  since
due to a lack of time I did not feel like porting the stuff that used
to be in there to the 2.x versions. Maybe it'll be back in 2.2 or so.


Copyright 1990, 1992-1999, 2001-2002 by  Stefan De Troch  and  Michel

Versions 2.0 and above of xautolock  are available under version 2 of
the GNU GPL.  Earlier versions are available under other  conditions.
For more information, see the License file.


Xautolock was conceived, written, and performed by:

 Michel Eyckmans (MCE)       eyckmans@imec.be
 Stefan De Troch             stefan@specs.philips.com

Please  send queries for help, feature suggestions, bug reports, etc.
to eyckmans@imec.be only.
xautolock, particularly when using tvtwm).


Special thanks to:

 Kris Croes                  croes@imec.be

And the many people who submitted bug reports, patches, suggestions,
kudos, etc.

No thanks to a certain commercial X server provider who  volunteered
to beta test version 1.9 on many,  *many* platforms  but didn't live
up to it.  Also our apologies to the candidate beta testers who were
not retained because of this candidate.

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