Error executing script command returned: 256 Topic is solved

[JanvdW]

In that case I don't understand why your script is executed in the background, because there's no ampersand in the script?

[waaren]

In that case I don't understand why your script is executed in the background, because there's no ampersand in the script?

Because the script does not use the Lua functions os.execute or io.popen but a separate (and async) thread coded in the domoticz program called by the dzVents function dz.executeShellCommand()

[JanvdW]

Thanks; the script works fine. I'll have a look at my other Blockly's to optimize the system

[JanvdW]

As discussed I am changing my scripts to async versions, but I am struggling with one of my scripts. It's a script that checks presence of family members based on ip connection of their mobiles phone:

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return { on = { timer  = { "every 5 minutes" } },

    logging = {  level  = domoticz.LOG_INFO, marker = "Ping smartphones" }, 

    data = { timeoutcount = { initial = {} } },

    execute = function(dz, device)
        local devices_ping =  { ['Smartphone 1']    = 'xx.xx.xx.xx',
                                ['Smartphone 2']    = 'xx.xx.xx.xx',
                                ['Smartphone 3']    = 'xx.xx.xx.xx',
                                ['Smartphone 4']    = 'xx.xx.xx.xx',         
                                ['Smartphone 5']    = 'xx.xx.xx.xx'} 
        local timeout       = 3                                                			-- # timeouts, before a switch off will be executed
        local timeoutcount  = dz.data.timeoutcount                              -- short reference
        for deviceName, ipaddr in pairs(devices_ping) do
            ping_success=""
            ping_success=os.execute('ping -c1 -w1 ' .. ipaddr)

            if timeoutcount[deviceName] == nil then
                    timeoutcount[deviceName] = 0
            end

            if ping_success then
                if timeoutcount[deviceName] == 0 then
                    print("ping "..deviceName.." success ")
                else
                    if timeoutcount[deviceName] >= timeout then                 -- log wordt alleen weggeschreven als device offline is geweest
                        print("ping "..deviceName.." success, device is back.")
                    end
                    timeoutcount[deviceName] = 0                                	-- reset the counter
                end
                if dz.devices(deviceName).state == 'Off' then
                    dz.devices(deviceName).switchOn()
                end
            elseif timeoutcount[deviceName] < timeout then
                timeoutcount[deviceName] = timeoutcount[deviceName] + 1
                print("ping ".. deviceName .." ".. timeoutcount[deviceName] .." times failed.")
            end   

            if timeoutcount[deviceName] >= timeout then
                --print ("ping ".. deviceName .." has " ..timeoutcount[deviceName].. " timeouts, this exceeds the timeout number setting.")
                if dz.devices(deviceName).state == 'On' then
                    dz.devices(deviceName).switchOff()
                end
            end
        end
    end
}

I added an ampersand to the os.execute command as follows:

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ping_success=os.execute('"ping -c1 -w1 " .. ipaddr &')

. It seems to work (no errors), but results always in positive values, even when devices are not connected. Is something wrong with the syntax?

[waaren]

As discussed I am changing my scripts to async versions, but I am struggling with one of my scripts. It's a script that checks presence of family members based on ip connection of their mobiles phone:

I added an ampersand to the os.execute command as follows:

Code: Select all

ping_success=os.execute('"ping -c1 -w1 " .. ipaddr &')

. It seems to work (no errors), but results always in positive values, even when devices are not connected. Is something wrong with the syntax?

Not directly with the syntax but the os.execute does not return the resultcode of the ping command but it returns the result of the &, meaning that it returns the result of sending the command to the background which always succeeds.

This behavior was one of the main reasons to develop the executeShellCommand() in dzVents (available in dzVents >= 3.1.0 / build >= 12771) which is true async and returns its result via trigger shellCommandResponses

[JanvdW]

That explains what happens; thanks for your explanation. I had a look already at executeShellCommand() already, but it was not clear to me how to use it in a loop, where the executeShellCommand() is called for multiple (in my case 5) devices.

[waaren]

That explains what happens; thanks for your explanation. I had a look already at executeShellCommand() already, but it was not clear to me how to use it in a loop, where the executeShellCommand() is called for multiple (in my case 5) devices.

In this case I would leave the looping to the ShellCommand. Below small bash script will do it for you and nicely shows the result in a JSON that can be processed further in dzVents when it is returned by the shellCommandResponse

bash script

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#! /bin/bash

#
# bash script to loop over all parms and ping them. Parms should be a valid IPv4 or IPv6 address or hostname 
# 
# call like  ./myPing.sh dz 192.168.192.1 192.168.192.199 8.8.8.8 noHost ::1 home.synology.me
# output will look like 
#
# {"dz":0,"192.168.192.1":0,"192.168.192.199":1,"8.8.8.8":0,"noHost":2,"::1":0,"home.synology.me":0,}
#

myJSON='{'

#
# Loop over all parms
#
for ((i=1; i<=$#; i++))
do
  ping -q -c1 -w1 ${!i}  > /dev/null 2>&1  
  myJSON=$myJSON\"${!i}\":$?, # add ip + result to the JSON
done

echo ${myJSON::-1}"}" # remove last , and add }

dzVents part

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local scriptVar = 'shell pinger'

return
{
    on =
    {
        timer =
        {
            'every minute',
        },

        shellCommandResponses =
        {
            scriptVar,
        },
    },

    logging =
    {
        level = domoticz.LOG_DEBUG,
        marker = scriptVar,
    },

    execute = function(dz, item)

        if item.isTimer then

            local IPTable =
            {
                "dz",
                "192.168.192.1",
                "192.168.192.199",
                "8.8.8.8",
                "noHost",
                "::1",
                "home.synology.me",
            }

            dz.executeShellCommand(
            {
                command = '/home/pi/domoticz/scripts/myPinger.sh ' .. table.concat(IPTable,' '),
                callback = scriptVar,
                timeout = #IPTable -- same number of seconds as there are entries in IPTable
            })
        elseif item.isShellCommandResponse and item.json then
            rt = item.json
            for host, rc in pairs(rt) do
                dz.log('Ping result of "' .. host .. '" : ' .. rc, dz.LOG_DEBUG)
            end
        else
            dz.log('There was a problem handling the command', dz.LOG_ERROR)
            dz.log(item, dz.LOG_DEBUG)
        end
    end
}

[JanvdW]

That's a good idea to solve this.

I implemented this but have some errors:

• strange enough I get the following error message:

  Code: Select all

  Error: dzVents script command running longer than specified timeout(5 seconds), cancelling...

• At other moments I get log entries like

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  2021-02-23 14:20:05.736 Error: dzVents: Error: (3.1.5) shell pinger: Error parsing json to LUA table: /home/pi/domoticz/scripts/dzVents/../lua/JSON.lua:808: trailing garbage at byte 231 of: {"xx.xx.xx.xx":0,"xx.xx.xx.xx":0,"xx.xx.xx.xx":0,"xx.xx.xx.xx":1,"xx.xx.xx.xx":1}
  2021-02-23 14:20:05.736 {"xx.xx.xx.xx":0,"xx.xx.xx.xx":0,"xx.xx.xx.xx":0,"xx.xx.xx.xx":1,"xx.xx.xx.xx":1,"xx.xx.xx.xx":0,"xx.xx.xx.xx":0,"xx.xx.xx.xx":0,"xx.xx.xx.xx":1,"xx.xx.xx.xx":1,}
  2021-02-23 14:20:05.736 Error: dzVents: Error: (3.1.5) shell pinger: There was a problem handling the command
  2021-02-23 14:20:12.657 Error: dzVents script command running longer than specified timeout(5 seconds), cancelling..

[erem]

@JanvdW

check your line endings in the script.
I'll bet the trailing garbage is cr-lf from a cut-paste from a windows editor.

[JanvdW]

Found the issue; it appears that the bash script was corrupted.

I have one question left. Based on the timer the script starts at 20:45:00.726 and finished at 20:45:00.826. Then the ShellCommandResponse starts the script at 20:45:05.035 and finished at 20:45:05.062

I don't understand why I get an error message that timeout of 12 seconds is exceeded:

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Error: dzVents script command running longer than specified timeout(12 seconds), cancelling...

. A message that I get over and over again.

[waaren]

I don't understand why I get an error message that timeout of 12 seconds is exceeded:

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Error: dzVents script command running longer than specified timeout(12 seconds), cancelling...

. A message that I get over and over again.

What is your build?
The errormessage could be the bug that was introduced in build 12970 and fixed in build 12974
If you are on build >= 12974 and still see the message then try and change line

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timeout = #IPTable -- same number of seconds as there are entries in IPTable

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timeout = ( #IPTable + 10 ) -- same number of seconds as there are entries in IPTable + 10 

[JanvdW]

Great; thanks. The system was on build 12972. After upgrade (to 12983) the error message is gone.