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  ledblink 0.85
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What is it?
-----------

For every LED you wish to control (keyboard or connected to parallel
port) an instance of ledblink must be started running in the
background. These "server" processes can then be controlled to make
the LED blink to show certain events (arrival of new mail for
example). The blinking rate can be modified to show numerical values
(number of new mails).


Installation
------------

Building and installing should be quite straight forward:

make
make install

By default files are installed in /usr/local but you can change this
by adding "PREFIX=<your path>" to "make install".

To get access to the keyboard and parport LEDs and for writing its PID
to /var/run ledblink needs root privileges. It should be save to
install ledblink suid-root ("chmod +s /usr/local/bin/ledblink" as
root).


Usage examples
--------------

(These examples expect that ledblink is installed suid-root)

First start up a background process:

~$ ledblink
ledblink running with PID 5188.

This will now control the scroll lock LED (the default). You can
specify other LED using the -l parameter (see manpage for details). 
Now let's start blinking:

~$ ledblink -b

Repeat this command to blink more often. You would usually put this
call in the "exec on mail arrival" option of you mail checker.

The blinking rate can be decreased again by calling:

~$ ledblink -d

or can be stopped completely with:

~$ ledblink -s

You can also control the usual state of a LED:

~$ ledblink -1

Now the LED will be on by default and will blink by switching to the
off state shortly.

If you do not need ledblink anymore, the background process can be
shut down:

~$ ledblink -k
Process 5212 killed.


History
-------

I was looking for a program that started blinking a keyboard LED when
new mail arrived. After some searching I found mailblink by Don
Bindner. But there were two issues: Firstly it did not work as
expected when there was a second program also checking for
mail. Secondly because of quite long checking intervalls the LED often
kept blinking for a while even after I already had read the mail.

After all I did not need all the mailchecking stuff, since I already
was running a mail check inside gkrellm, playing a sound and showing a
mail preview on arrival of new mail. So I removed all mail checking
code from mailblink and made the blinking controlable via signals. The
result was named ledblink.

You can get mailblink from http://vh224401.truman.edu/~dbindner/linuxware/


Distribution
------------

New releases can be downloaded from the ledblink homepage at
http://www.bitplanet.de/unix/ledblink.html


Contacting the author
---------------------

Please send bugreports/rants/anything to joerg.mensmann@gmx.de or
joerg@bitplanet.de.


Licence
-------

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
USA.
