Script to Monitor Remote System -

[jamesng]

Hi

I have a script which I use to monitor the zones in a remote alarm system.    It's a looping script which processes the data coming in from a socket connection.  I need one instance of the script running continuously.

What's the best place to locate this (script below) - is it as a resident script with a 0 interval time or as an init script or somewhere else?

Many thanks in advance

Kind Regards,
James

Code:

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-- Initialise socket connection if not sock then   require('socket')   sock, err = socket.connect('192.168.1.100', 2401)   if sock then     sock:settimeout(1)   else     log('Error connecting ' .. err)     sleep(5)   end end -- Process data received if sock then        while true do     rec = sock:receive('*l')     if rec then              data = lmcore.hextostr(rec, true)       st, addr, len, cmd, event, id, area = data:byte(1, 7)           if (event == 0) then           log('Door open in Zone ' .. id)         else           log('Door closed in Zone ' .. id)         end           end   end   end

[admin]

You can make multiple copies of this script as a resident script with sleep time set to 0. init script should not have any blocking or long-running parts.

Also non-blocking connect should be used and possible errors during receive should be checked:

Code:

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if not sock then   sock = require('socket').tcp()   sock:settimeout(1)   res, err = sock:connect('192.168.1.100', 2401)   if not res then     log('connect failed', err)     sock:close()     sock = nil     os.sleep(1)   end end if sock then       res, err = sock:receive('*l')   if res then     -- parse res   elseif err == 'closed' then     log('connection closed')     sock:close()     sock = nil   end end

[jamesng]

Thanks for the script refinements. I’m still a little confused - if this shouldn’t be run a resident or Init script then what type of script would you suggest I create this as?


Kind Regards
James

[admin]

I've never said it shouldn't be a resident script. Resident script is exactly what is needed for such task.

[jamesng]

But won’t multiple instances of the same script running cause issues / use up all the available device memory?

What time interval would you suggest or modifications to the script to avoid the above?

Kind Regards
James

[admin]

You can run multiple instances without any issues. Sleep interval must be set to 0 in this case. Most of the time the script is in a suspended state waiting for data to arrive so it does not consume CPU resources.

[jamesng]

Thanks for clarifying. Many thanks.