The apuledctld daemon is designed to monitor of the button on front panel of PCEngines APU<x> devices.
In addition, it can control the illumination of three LEDs on front panel according to the scheme
given in configuration file.

Daemon lights LEDs according to builtin "running" scheme when started without parameters and then
tracks the front panel's button state. Long press a button for a period specified in configuration
file will invoke command specified in configuration file.

When started with '--startup' parameter, LEDs will be light up according builtin "startup" scheme
and then as described above.

During button pressing LEDs lights up according builtin scheme "press". If button released 
before period expires, LEDs state returns to the previously used scheme.

*** LEDs BLINKING SCHEMES ***

Schemes can be of two types: permanent and cyclic. Permanent scheme lights up LEDs once according
to the specified parameters, cyclic scheme lights up LEDs in the loop.

Blinking scheme is specified in configuration file according to the following syntax:

blink:<scheme name>:<bitmap>:<light time (ms)>[:<bitmap>:<light time (ms)>]...
scheme name - any string up to 256 chars
bitmap - integer where bits 0,1 and 2 indicates the state of LEDs 1,2 and 3 respectively
    for example - 5 (LED 1 and 3 is on and LED 2 is off)
light time - LED glow time (in milliseconds) according to the bitmap.


If the scheme has only one pair "bitmap:light_time", such scheme is considered static and light_time 
is ignored, a value of -1 must be assigned. If there are more than one pair, the scheme 
is considered cyclic, and light_time value must be a positive integer. Number of pairs is limited 
by maximal  line length of 1024 bytes.

For example:
blink:running:5:-1
A static scheme, where LEDs 1 and 3 constantly on.

blink:startup:1:300:2:300:4:300
A cyclic scheme, where LEDs 1, 2 and 3 light subsequently with 300 ms. interval

blink:press:5:100:0:100
A cyclic scheme where LEDs 1 and 3  turn (go) on and off with 100 ms. interval.

Number of schemes in config file is unlimited. Three schemes must be defined:
'startup', 'running' and 'press'
Other schemes can have arbitrary names.

When the daemon is running, it is possible to switch schemes using signals:
SIGUSR1: switching to the “startup” scheme
SIGUSR2: switching to the “running” scheme
SIGHUP: switching to the scheme specified in the text file /var/run/apuled-scheme
For use of SIGHUP daemon is supplied with a shell-script 'al_chscheme'

*** ACTION TO BE EXECUTED AFTER CLICKING THE BUTTON ***

Action to be executed after clicking the button is specified in the configuration file according to the following syntax:
following syntax: <button click time>:<command>
Button click time - time in seconds
Command - any command or script (full absolute path)

If ‘startup’ scheme is active button click is ignored
After executing the command specified in configuration the daemon finishes its work.
When the button is pressed LEDs are activated according to the ‘press’ scheme, if the button press was 
shorter than specified in configuration, LEDs’ activation returns to the scheme that was active during 
the button pressing.

Only one action can be specified, in case there are several of them, the last one will be active.

For example:
action:5:/usr/local/etc/rc.reboot
After continuously pressing the button for 5 seconds /usr/local/etc/rc.reboot script will run